Category: Building Science

TL;DR: Whole house surge protection is not required by code in Idaho. The 2023 National Electrical Code makes it mandatory on a house, and then Idaho’s own amendment deletes dwelling units from that requirement — so a dorm room in Rexburg has to have it and your custom home does not. I spec it anyway, at the panel, on every build. It is one of the cheapest line items in the electrical package and it protects the most expensive ones.

I have been in construction about twenty years, and this is one of the few items where I have watched the code move in the opposite direction from where I would have bet. Nationally, surge protection on a house went from optional to mandatory. In Idaho, it went back to optional, on purpose, in writing.

Most clients have never heard of it. It shows up as one line on an electrical bid, somewhere between the smoke detectors and the exterior receptacles, and it is one of the easiest things in the world to cut when you are trimming a budget in month six. So here is the straight version: what the code says, what the thing actually does, what it does not do, and what I put in.

Is whole house surge protection required by code in Idaho?

No. Idaho specifically took houses out of the requirement, and it is worth understanding exactly how, because the answer in almost every other state is yes.

Electrical work in Idaho is different from the rest of your building permit. Your structural and energy code comes from the county. Teton County, Idaho is on the 2018 family of I-Codes, for instance. Electrical is statewide. The Idaho Electrical Board adopts the code and runs the inspections through the Division of Occupational and Professional Licenses, so the electrical rules are the same in Driggs, Rigby and Rexburg no matter what the county did.

Under IDAPA 24.39.10, Idaho adopts the 2023 National Electrical Code and then amends it with 34 state amendments, lettered (a) through (hh). Three of those amendments deal with surge protection, at NEC sections 215.18, 225.42 and 230.67. All three read the same way. Each one says the section “shall apply in full,” then adds an exception: “For dwelling units, a surge protection device shall be permitted when installed in compliance with” subsections (B) through (E). And each one ends with the line that does the real work: “Delete section 230.67(A) list item (1).”

List item (1) is dwelling units.

In the 2023 NEC, section 230.67(A) lists four occupancies whose service has to be provided with a surge protective device: dwelling units, dormitory units, hotel and motel guest rooms and suites, and areas of nursing homes and limited-care facilities used exclusively as patient sleeping rooms. The 2020 edition had covered dwelling units only; the 2023 cycle expanded it. Idaho adopted the expansion and then struck houses from the list.

So the practical result in Idaho is this: a dormitory at a university, a motel room, and a patient sleeping room all require surge protection at the service. A single-family custom home does not. If you install one on a house — and you should — it has to be installed correctly per the rest of the section, but nobody is going to fail your rough-in for leaving it out.

This is not an isolated edit, either. The same amendment list narrows NEC arc-fault protection down to bedrooms only in one- and two-family dwellings, where the national code is far broader. Idaho has a consistent habit of trimming the electronics-protection requirements back on houses and leaving the decision to whoever is building. On my jobs that decision is mine, and I make it the same way every time.

One scheduling note while we are in the rule book. Idaho requires the electrical permit to be purchased before work commences, the permit holder has to request the inspection, and no wiring or equipment may be concealed from sight until it has been inspected. A permit expires 365 days after purchase. That is why surge protection is a design-phase decision and not a drywall-day decision — see what inspections happen on a custom home build for where the electrical rough-in falls in the sequence.

What actually causes a power surge in a house?

Your own appliances, most of the time. That is the part that reframes the whole conversation, because almost everybody assumes this is a lightning product.

A surge is a very short, very fast voltage spike — a rise above about 110 percent of nominal voltage, lasting on the order of one to ten microseconds. It is not an outage, and your breakers will not catch it. A circuit breaker protects against too much current for too long. A surge is too much voltage for almost no time at all, and it passes through a breaker like it is not there.

On where they come from, the numbers published by utilities and equipment manufacturers land in the same place. Orcas Power and Light Cooperative, an electric co-op, puts it at about 80 percent of all power surges being created by electronic equipment inside the home, with lightning accounting for only around 15 percent. Major switchgear manufacturers publish a near-identical figure from the other direction: up to 80 percent of surges occur on the customer side of the meter.

What is doing it inside the house is anything with a motor or a compressor cycling on and off. The air conditioner. The refrigerator. The well pump. A shop vac in the garage. Every time an inductive load drops off the circuit, the collapsing magnetic field dumps a spike back into the wiring. A house does that hundreds of times a day, every day, for thirty years.

Where it comes from	Roughly how often	What it looks like	What stops it
Your own motors and compressors cycling	About 80% of surges	Small, constant, cumulative — nothing visibly happens	Panel-level device, plus point-of-use at sensitive gear
Utility switching, reclosing, capacitor banks	Common on rural feeders	Bigger spike, often right after an outage comes back	Panel-level device at the service
Lightning, nearby strike or induced on the line	About 15% of surges	Large, fast, can be destructive	Panel-level device helps; a direct hit is a different problem
Lightning, direct strike on or near the house	Rare, especially here	Catastrophic	Nothing in this article. A surge device is not a lightning arrestor

I want to be straight about that last row, because the marketing in this category is not. A panel-mounted device will not survive a close lightning strike and it is not sold as protection against one. Surge protection reduces the damage from the frequent, small, unglamorous events and from the moderate ones. It does not make a house lightning-proof.

Does lightning even matter in eastern Idaho?

Barely, and I would rather tell you that than sell you something on a scare. This valley is one of the quietest places in the country for lightning.

The National Weather Service publishes a cloud-to-ground flash density table by state, averaged over 2008 through 2017 from the National Lightning Detection Network. Idaho comes in at 0.9 flashes per square mile per year, which puts it 46th. Florida, at the top, is 20.4, more than twenty times our rate.

State	Cloud-to-ground flashes per square mile per year	Rank
Florida	20.4	1
Wyoming	2.7	37
Utah	2.2	42
Montana	2.1	43
Nevada	1.1	45
Idaho	0.9	46
California	0.5	47
Oregon	0.5	48
Washington	0.4	49

Interesting wrinkle for anyone building here from the Wyoming side of the pass: Wyoming has three times Idaho’s flash density. Same mountains, different number.

So if lightning is the argument, the argument is weak in Teton Valley. The reason I still put surge protection on every house is the other 80 percent — the constant internal stuff — plus one local factor that does not show up in a lightning map.

Rural electric service switches more than city service does. Fall River Rural Electric Cooperative, which serves most of Teton Valley, is actually very good by national standards: it reported a 2022 outage average of 165 minutes per member against more than 500 minutes for the all-Idaho utility average that year, and a five-year average under 300 minutes per member. For context, the U.S. Energy Information Administration’s Electric Power Annual put the national figure at about 11 hours without power in 2024. Our co-op is not the problem.

But every one of those interruptions ends with power coming back, and reclosers and capacitor switching on a long rural feeder are exactly the kind of events that produce a spike at the service. The house that rides out eight outages a winter also absorbs eight restorations. That is the local case, and it is an honest one.

What does a surge actually destroy in a new custom home?

Circuit boards. Which, in a house built in 2026, is most of what you paid for.

Think about what is actually on a modern custom home’s electrical system. Thirty years ago a surge found a water heater element, a furnace blower motor and a few light bulbs. Today it finds:

• The HVAC equipment. A variable-speed ECM blower and an inverter-driven compressor are both electronics. A cold-climate heat pump is essentially a computer bolted to a refrigerant circuit, and the control board is not a cheap part.
• The water heater. A tankless unit has a control board, a flow sensor and a modulating gas valve. A failed board on a tankless heater is a service call, a part on order, and cold showers in between.
• The well pump controller. On a rural lot, a variable-frequency constant-pressure controller is what gives you consistent well water pressure at the fixtures. It is also a drive, and drives do not like voltage spikes.
• The ventilation and filtration equipment. An HRV or ERV running whole house ventilation, plus the ECM blower pushing air through a deep air filtration cabinet, are both electronically commutated.
• The softener head. The control head on a demand-initiated water softener is a small computer that decides when to regenerate.
• Every LED driver in the house. This is the one nobody expects. A surge rarely kills an LED fixture outright; it degrades the driver, and the fixture starts flickering or dies early. On a house with 120 cans and a lighting control system, that is a real number.
• The lighting control system, the network gear and the camera NVR. If you are doing any of the smart home systems I spec, the processors and switches are the brains of the house.
• Appliances. Induction ranges, the refrigerator inverter, the dishwasher board.

Here is the part that makes this worth doing rather than merely interesting. A surge event usually does not announce itself. Nothing bangs, nothing trips, nothing smells. The equipment just degrades a little, and then something fails eighteen months later and reads as a defective part. That is why clients rarely connect the two, and why nobody walks into a design meeting asking me about surge protection. It is a failure mode that never gets attributed to its cause.

What kind of device goes at the panel?

A Type 1 or a Type 2 surge protective device, and the difference is just where in the service it is allowed to connect.

The NEC sorts these devices into types by installation point, and the code requirements for each type are spelled out in NEC Article 242:

	Type 1	Type 2	Type 3
Where it connects	Can go on the supply side of the service disconnect, including the meter base	Load side of the service disconnect overcurrent device	Load side of branch-circuit overcurrent protection, at the equipment
What it is in practice	Meter-base or line-side unit, often installed by the utility or a lineman	Panel-mounted or breaker-style device in or next to your load center	Plug strip, wall-tap, or a module at one piece of equipment
Satisfies NEC 230.67 where required	Yes	Yes	No
Catches surges coming in from the utility	Yes	Yes	Only what reaches that one outlet
Catches surges created inside the house	Partly	Partly	Yes, at the device it serves
Minimum distance rule	—	—	If the manufacturer requires it, at least 30 feet of conductor from the service disconnect
Who I have install it	Electrician, coordinated with the co-op	Electrician, at electrical rough-in	Homeowner, after move-in

Two things worth pulling out of that table. First, Type 1 devices are usually dual-rated so they can be used in Type 2 locations too, which is why a good electrician will often just spec a Type 1 and put it at the panel. Second, a plug strip is a Type 3 device and it is not a substitute for either of the first two. More on that below, because it is the question I get most.

Which numbers on the spec sheet actually matter?

Four of them, and they are not the one printed biggest on the box.

Every one of these devices is built around metal oxide varistors, which shunt surge energy away from your wiring and absorb a little damage doing it. The spec sheet describes how much they can absorb and how much voltage gets past them while they do it.

Spec	What it means	What to ask for	Why it matters
Nominal discharge current (In)	The surge current the device can take repeatedly without failing	At least 10 kA	The 2023 NEC made 10 kA the floor where surge protection is required. Use it as your floor even though Idaho exempted houses
Voltage protection rating (VPR), also called let-through	How much voltage still reaches your equipment while the device clamps	Lower is better; 330 V or less on a 120 V leg is the common benchmark	This is the number that decides whether your LED drivers survive. A high kA rating with a sloppy VPR is a bad trade
Peak surge current rating (kA)	The one-time maximum it can survive	Co-ops commonly suggest 39,000 A or more for point-of-use gear	This is the number marketing shouts. It relates to life expectancy more than to protection quality
UL 1449 listing	The product safety standard for these devices	Non-negotiable. A plain power tap is not a listed SPD	Unlisted devices are the reason this category has a bad reputation

The field detail that does not appear on any spec sheet: lead length matters, a lot. Every inch of wire between the device and the bus adds roughly 15 to 25 volts of let-through. Six inches of extra conductor can undo the difference between a good VPR and a mediocre one. This is why I want the device mounted tight to the panel with the leads cut as short as they will physically go, and why I would rather have a competent electrician install an average device properly than a great device sloppily.

Do I still need power strips if I have whole house surge protection?

Yes, at a handful of locations. Panel-level and point-of-use do two different jobs, and the whole house surge protection at your service does not make the second one unnecessary.

The panel device is a dam. It takes the big energy, mostly what comes in from outside, and shunts it to ground before it gets into the branch circuits. What it cannot do is stop a spike that is created downstream of it — the refrigerator compressor on the kitchen circuit kicking off and sending a spike at the kitchen outlets. The energy never passes the panel, so the panel device never sees it.

Which is why the right answer is layered, and why the phrase “whole house surge protection” oversells itself a little:

1. At the service: a Type 1 or Type 2 device at or immediately next to the panel. This is the one that goes in during construction and the one I put on the electrical plan.
2. At the equipment that matters: listed Type 3 devices at the network rack, the lighting control processor, the camera recorder, the office, the media equipment and the well pump controller.
3. Nothing at all on the stuff where it does not pay — table lamps, the vacuum, the garage freezer.

Co-op guidance on the point-of-use pieces is worth repeating because it is more specific than most: look for UL 1449 listing, a peak surge current rating of 39,000 amperes or more, let-through voltage of 330 volts or less, 420 joules or more, an outlet for each device rather than a daisy chain, a status indicator, and a warranty of at least five years. And protect the data lines too, because a surge that comes in on a coax or ethernet run does not care what you did at the panel.

Where does the device go, and when does it get installed?

At or immediately beside the load center, and it goes in at electrical rough-in — which means the decision belongs in design.

The code is specific about location where it does apply: the device has to be an integral part of the service equipment or located immediately adjacent to it. There is an exception allowing it at each next-level distribution equipment downstream toward the load instead, which is how you handle a house with a main panel in the garage and a subpanel in the mechanical room. On a larger build with two or three subpanels, that exception is the one your electrician will be working from.

Practically, there are three ways this lands:

• Breaker-style, in a panel space. Cleanest install, shortest leads, and it costs you one or two breaker spaces. Which is a real consideration, and it is one more reason the panel needs headroom, and panel headroom is the whole subject of what size electrical panel a new home needs.
• Surface-mounted beside the panel. Nipple-connected, leads kept short. What you use when the panel is full or the device is a larger unit.
• At the meter base. A Type 1 unit on the line side, coordinated with the co-op. Catches the most before it enters the house, but it is a utility conversation, not just an electrician conversation.

The sequencing point is the same one that applies to most of the invisible systems in a house: this is a line on a drawing, not a decision made in the field. We handle plan development and engineering coordination in house, so the panel location, the panel size, the SPD, the generator interlock and the subpanel layout all get resolved on one sheet during the design agreement. Adding a device after the fact is not hard, but by then nobody is thinking about it, and that is how it gets skipped.

Worth saying plainly: because Idaho exempted dwellings, the inspector is not going to catch its absence. On most code items the inspection is your backstop. On this one, there is no backstop.

How long does one last, and how do I know when it is dead?

It wears out, and this is the part almost nobody is told at handoff.

A surge protective device is a consumable. Every surge it absorbs degrades the varistors inside it a little, and eventually it stops protecting anything. The device does not disconnect itself or announce the problem. Power keeps flowing. The house keeps working. The protection is simply gone.

That is why a status indicator is not a nice-to-have. A decent unit carries an indicator light, or per-phase indicators, that tell you the protection circuit is still alive. On a house that lives behind a long rural feeder, I want that light somewhere a person will actually look — which in practice means the mechanical room wall next to the panel, not buried behind a water heater.

Two other things on the life of the device:

• Service equipment replacement resets the obligation. Where the code requires surge protection, replacing the service equipment means the whole section applies again. If you ever upgrade the service on an older house, this is the moment the device gets added.
• A warranty on connected equipment is not a protection plan. Several manufacturers offer one. Read what it actually covers and what it requires of you. I treat it as a tiebreaker between two otherwise equal devices, not as a reason to pick a weaker one.

I put the model, the install date and the indicator location in the closeout package, along with the rest of the equipment documentation. A device nobody knows about is a device nobody will ever check.

What about the well pump, the generator and the battery?

Each one changes the picture a little, and on a rural Teton Valley lot you will likely have all three.

The well pump is the single best argument for this whole line item on a rural build. It is a motor at the end of a long run, usually with a drive controller, and losing it means losing water in the house. It is both a major source of internal surges and a major victim of them. I want a listed device at the pump controller in addition to the one at the panel.

The generator adds a wrinkle. A standby generator with an automatic transfer switch means your house gets its power from two sources, and the transfer event itself is a switching event. Where the SPD sits relative to the transfer switch decides what it protects during a generator run. That is a question for your electrician at design, and the answer depends on whether the switch is service-rated and where the panel lands. Ask it before the equipment is ordered, not after.

Battery storage is where Idaho’s amendments show up again. The state amendment list requires energy storage systems to be listed, with an exception for lead-acid, and requires the ESS disconnect or remote control to be readily accessible. A battery system is an inverter, which is to say a large expensive circuit board with its own protection requirements from the manufacturer. If you are putting in a battery, the manufacturer’s surge requirements govern and they are usually stricter than anything in the code.

Same logic runs through most of the mechanical systems on a rural build. The more of the house that depends on a drive, a board or an inverter, the more a twenty-dollar-a-year insurance policy at the panel makes sense.

What does it cost, and what is not in that number?

I am not going to publish an install price for this, and I want to explain why rather than just dodge it.

The third-party cost pages that rank for this search are, almost without exception, generated content with numbers nobody verified. I would rather give you the drivers and have you hold your electrician to a real line item than give you a figure that is wrong for your house. What moves the number:

• Device class and ratings. A breaker-style Type 2 unit and a high-capacity dual-rated Type 1 are not in the same bracket.
• Panel spaces. A breaker-style device consumes spaces. If the panel is tight, you are either upsizing the panel or surface-mounting beside it.
• Number of panels. A main plus two subpanels is potentially three devices, depending on how your electrician applies the downstream exception.
• Meter-base work. A line-side Type 1 involves the co-op and their schedule.
• Point-of-use count. How many pieces of equipment get their own listed device, and whether the data lines get protected too.
• Retrofit versus rough-in. At rough-in it is a small adder on an electrical bid. After drywall, with a full panel, it is its own trip and its own permit.

What I will tell you is where it sits in the hierarchy. On any build I have run, surge protection at the panel is one of the lowest-cost items on the electrical bid and it sits upstream of some of the most expensive equipment in the house. That ratio is the entire argument. It is the same test I apply to every other line in which custom home upgrades are actually worth the money: can you change it later, and what does it protect?

Where it goes wrong is in a vague allowance. If “electrical” is one lump number on your bid, surge protection is invisible inside it and it is the first thing to quietly disappear when the electrician is squeezed. Ask for it as its own line. That pattern — real items vanishing into round allowances — is behind most of the hidden costs of building a custom home, and it is why I carry this as a named item rather than a plumbing-style allowance. For how the electrical package fits a whole-project budget, start with the honest cost to build in Teton Valley.

What I spec on a SwagerBuilds build

Same thing every time, and it is short.

During the design agreement, the panel location, panel size and surge protection all get decided together, before any construction price is signed. It goes on the electrical plan as a named item with a rating, not as a note saying “contractor to provide.”

The device: a listed Type 1 or Type 2 unit at the service, nominal discharge current of at least 10 kA, the lowest voltage protection rating I can get at that capacity, with a status indicator, mounted tight to the panel with the leads as short as they will go. If there are subpanels, we settle at design whether each one gets its own.

At the equipment: listed point-of-use devices at the well pump controller, the lighting control processor, the network rack and the camera recorder. Data lines protected, not just power.

At the electrical rough-in inspection, it is verified in place before anything gets covered. Idaho will not fail you for its absence, so I check it myself. We run 24/7 cameras on every job, so if you are following the build from California you can watch the panel go in.

At closeout, the model, install date, ratings and the location of the indicator light go in the package with everything else, plus the plain-English version: this part wears out, here is the light that tells you, look at it once a year.

I am involved in every phase of every build, which is why I care about a part that costs less than a nice faucet. It sits upstream of the heat pump, the tankless heater, the well pump, the lighting system and every LED driver in the house. Skipping it is not saving money. It is deferring a repair you will not connect to its cause.

Thinking about a build in Teton Valley, Jackson Hole or Eastern Idaho? Bring me your plans or your lot and I will walk you through what I would put on the electrical sheet. Start with how I build, look at the custom homes page, or reach out directly. You can also call me at (208) 520-0636. Design is sold as a design agreement with a fixed design fee, quoted per project. If you are earlier than that, the questions custom home buyers ask page is the fastest way to get oriented.

Frequently asked questions

Is whole house surge protection required by code in Idaho?

No. Idaho adopts the 2023 National Electrical Code under IDAPA 24.39.10, which requires a surge protective device at the service for dwelling units, dormitories, hotel and motel guest rooms, and nursing home patient sleeping rooms. Idaho’s own amendments then delete dwelling units from that list at NEC 215.18, 225.42 and 230.67, and state that for dwelling units a surge protection device is permitted rather than required. A dorm room in Idaho must have one. A single-family house does not.

Does a circuit breaker protect against power surges?

No. A breaker protects against too much current flowing for too long, which is an overload or a short circuit. A surge is a voltage spike above roughly 110 percent of nominal lasting one to ten microseconds, and it passes through a breaker without tripping it. Surge protection and overcurrent protection are two different jobs done by two different devices, and arc-fault and ground-fault breakers do not cover it either.

Is a power strip the same as whole house surge protection?

No. A plug strip is a Type 3 device under the NEC and protects only what is plugged into it, from surges that have already entered the branch circuits. A Type 1 or Type 2 device at the service panel takes the larger events, mostly those arriving from the utility, before they reach any circuit. The two are complements, not substitutes. A plain power tap with no UL 1449 listing is not surge protection at all.

Does surge protection stop lightning damage?

It helps with induced surges from a nearby strike and does nothing meaningful against a direct hit. A panel-mounted device is not a lightning arrestor and will not survive close lightning. Eastern Idaho is a weak place to make the lightning argument anyway: the National Weather Service puts Idaho at 0.9 cloud-to-ground flashes per square mile per year, 46th among the states, against 20.4 in Florida. The real case here is the roughly 80 percent of surges created by motors and compressors inside the house, plus utility switching on rural feeders.

How long does a surge protective device last?

There is no fixed interval, because it depends on how much surge energy it absorbs. The metal oxide varistors inside degrade with each event and eventually stop protecting, without interrupting power or giving any sign at the panel. That is why a status indicator matters and why it should be mounted somewhere a person will look. Where code requires surge protection, replacing the service equipment also triggers the requirement again, so a service upgrade is the natural moment to replace an old device.

Short answer: you need an engineered septic system when your lot’s soil, groundwater, slope or wastewater volume rules out a standard gravity drainfield. In Idaho that call is not a guess and it is not made by your builder. It is made from a test pit dug on your own lot, read by an environmental health specialist, and measured against the numbers in Idaho’s subsurface sewage rules.

On most buildable Teton Valley and Eastern Idaho lots a standard system works. On lots with shallow soil over fractured bedrock, high groundwater, heavy clay or more than about 20 percent slope, an engineered septic system is the only thing the health district will permit. I have built on both kinds, and the difference shows up in your budget long before it shows up in the ground.

What are my septic options in Idaho, in plain English?

There are three families of system, and the rules name them. A standard system is the simple one: a septic tank, an effluent sewer line, and gravel-filled trenches that let the liquid soak away by gravity. No pumps, no power, no moving parts. An alternative system is anything the state has written separate design guidance for because a standard trench will not work on that site. A large soil absorption system is for 2,500 gallons a day or more, which is subdivision and commercial territory, not a single house.

Inside the alternative family, Idaho’s rules call out a specific list of what it labels complex alternative systems: pressure distribution, sand mounds, intermittent sand filters, evapotranspiration systems, extended treatment package systems, proprietary treatment systems and lagoons. Those are the names you will hear from a designer. In practice, on a rural lot here, the two you are most likely to meet are pressure distribution, which uses a pump to dose the drainfield evenly instead of letting gravity dump into the near end, and a sand mound, which builds the drainfield up in imported sand above the native ground because there is not enough good soil below it.

One term worth clearing up early, because it causes real confusion: “engineered” is not a product you buy. It is a description of how the system got designed. A standard system is drawn off a table. An engineered septic system is designed for your specific soil profile, usually with a licensed professional engineer’s stamp on it, because no table covers your conditions.

Do I need an engineered septic system, or will a standard one work?

You need an engineered septic system when the test pit on your lot fails one of the thresholds in IDAPA 58.01.03, Idaho’s Individual and Subsurface Sewage Disposal Rules. Those thresholds are specific, and they are the whole ballgame:

• Not enough soil above groundwater. The rules require a minimum depth of suitable soil between the bottom of the drainfield and the next limiting layer down. Depending on your soil group that is roughly 3 to 6 feet above normal high groundwater or fractured bedrock, and 4 feet above an impermeable layer. Miss it and gravity trenches are out.
• Seasonal high groundwater too close. There is a separate, tighter clearance to seasonal high water. On valley-floor lots and anything near a creek or an irrigation ditch, this is the one that bites. Spring is when groundwater is highest here, which is exactly when most people are not out digging test pits.
• Soil that drains too fast or not at all. Gravel and extremely permeable material move effluent through before the soil can treat it. Clay, sandy clay, silty clay and hardpan will not take it at all. Both ends of that range are listed as unsuitable, and both push you to an engineered septic system.
• Too much slope. The natural slope of the drainfield site cannot exceed 20 percent. Absorption beds have a stricter ceiling and are ruled out above 8 percent. A lot of the pretty building sites on the benches above Driggs and Tetonia sit right around those lines.
• Volume. Past 2,500 gallons a day you are into a large soil absorption system, which must be designed by an Idaho-licensed professional engineer with plans reviewed by the state.

There is also a quieter trigger that catches people: a nutrient-pathogen evaluation. In areas where the groundwater is already carrying a nitrate load, the health district can require enhanced treatment, which means a treatment unit ahead of the drainfield rather than a bigger drainfield. That is a water-quality determination about the area, not about your soil, so a perfectly good-looking lot can still land there.

Here is the honest version of the answer: nobody can tell you from the road, from a plat map or from a satellite photo. I have walked lots that looked like gravel bars and tested into clay at 30 inches, and lots that looked like pasture and had 8 feet of beautiful sandy loam. The only thing that settles it is a hole in the ground and a specialist looking at the wall of it.

What does the soil test on my lot actually decide?

The health district’s environmental health specialist comes out, looks at a test pit, and assigns your soil to one of three design groups. That group assignment then drives everything downstream, including how big the drainfield is, how deep it can sit, and whether a standard system is allowed at all.

The groups run from coarsest to finest. Group A is the sands and loamy sands. Group B is the finer sands, sandy loam and loam. Group C is the silt loams, silts and clay loams. Each group gets a different soil application rate, which is just how many gallons per day each square foot of drainfield is allowed to absorb: roughly 1.0 gallon per square foot per day for Group A, 0.5 for Group B, and 0.2 for Group C. Outside those groups, with gravel at one extreme and true clays and hardpan at the other, the soil is simply listed as unsuitable.

Read that rate list again, because it is the most consequential set of numbers on this page. The same house on Group C soil needs five times the drainfield area it would need on Group A soil. Your house did not change. Your dirt did.

That is also why “my neighbor’s septic was cheap” is not evidence about your lot. Soil changes across a single parcel, let alone across a road. The test pit is cheap compared to being wrong.

How much of my yard does the drainfield take?

More than almost anyone expects, and this is where an engineered septic system starts to look less like a code technicality and more like a site-planning problem.

Start with the flow. Idaho’s rules size a dwelling at 250 gallons per day for a three-bedroom house, adjusted by 50 gallons per day for each bedroom above or below that. So a four-bedroom is 300 gallons a day, a five-bedroom is 350. Note that it is bedrooms, not square footage and not how many people actually live there. A 4,500-square-foot house with three bedrooms is sized the same as a 2,200-square-foot house with three bedrooms.

Now divide that flow by your soil’s application rate to get the required absorption area. Then double it, because the rules require your site to be big enough to build two complete drainfields, each sized for the full design flow. The second one is the replacement area. You do not install it, but you have to own the room for it, keep it undisturbed, and not drive on it, pave it or build on it. People lose their driveway alignment or their shop pad to that rule every year.

The arithmetic looks like this:

Bedrooms	Design flow	Group A soil (1.0 gal/sf/day)	Group B soil (0.5)	Group C soil (0.2)
3 bedroom	250 gal/day	250 sf, 500 sf with replacement	500 sf, 1,000 sf with replacement	1,250 sf, 2,500 sf with replacement
4 bedroom	300 gal/day	300 sf, 600 sf with replacement	600 sf, 1,200 sf with replacement	1,500 sf, 3,000 sf with replacement
5 bedroom	350 gal/day	350 sf, 700 sf with replacement	700 sf, 1,400 sf with replacement	1,750 sf, over the standard cap

That last cell is the one to understand. A standard trench system is capped at 1,500 square feet of trench area. A five-bedroom house on Group C soil needs more than that, so a standard system is mathematically unavailable before anyone even looks at your groundwater. You are into an engineered septic system by bedroom count alone.

This is a design-phase decision disguised as a dirt problem. Moving one bedroom to an office on the plans, before anything is drawn in ink, can be the difference between a gravity system and a pump, a panel and an annual service obligation. That is exactly the kind of trade we run during the design phase, while it is still free to change.

Standard, alternative and large systems: how they compare

	Standard system	Engineered / alternative system	Large soil absorption system
What it is	Tank, effluent sewer, gravel trenches, gravity flow	Pressure distribution, sand mound, sand filter, ET bed or a treatment unit ahead of the drainfield	Any system at 2,500 gallons per day or more
When it is allowed	Soil, groundwater separation, slope and flow all inside the table limits	One or more of those limits is missed, or a nutrient-pathogen evaluation requires treatment	Multi-home, subdivision or commercial flows
Who designs it	Sized from the rule’s tables by the installer and health district	Site-specific design, typically stamped by an Idaho-licensed professional engineer	Must be designed by an Idaho-licensed professional engineer
State plan review	No	Depends on the system and product	Yes, plans and specs reviewed by the state
Moving parts	None	Usually a pump, floats, a control panel and an alarm	Pumps, controls, often monitoring
Power required	No	Yes, so it is a load on your panel and a reason to think about backup power	Yes
Owner obligation after move-in	Pump the tank on a normal interval	Pumping plus ongoing service, and on treatment units an operating and monitoring requirement	Formal operation and maintenance
Can a homeowner install it themselves?	Yes, standard and basic alternative systems only	No, complex systems require a permitted complex installer	No

The row people skip is the second-to-last one. A gravity system is a thing you forget about between pump-outs. An engineered septic system with a pump and a panel is a piece of equipment that your house now owns, with an alarm that will eventually go off, and it needs power to work. If you are already weighing backup power on a rural lot, a septic pump belongs on that load list next to the well pump.

What do the setbacks do to my site plan?

Septic is the single most location-constrained thing on a rural lot, and the constraints come from two different agencies that do not share a rulebook. Idaho’s sewage rules set distances measured from the tank and drainfield. The Department of Water Resources well rules set distances measured from the well. You have to satisfy both at once.

The numbers that drive most site plans here:

• Drainfield to any well or domestic water supply: 100 feet. From the well side, the water rules say the same thing, 100 feet to a drainfield, and 300 feet if that drainfield is over 2,500 gallons a day.
• Septic tank to a well, spring or suction line: 50 feet for a private supply, 100 feet for a public one. The effluent pipe carries its own 50-foot separation from the well.
• Drainfield to permanent or intermittent surface water: 100 to 200 feet depending on your soil group, with the coarsest soils requiring the most distance. Irrigation canals, ditches and temporary water drop to 50 feet.
• Septic tank to surface water: 50 feet, and 25 feet to temporary water.
• Drainfield to the house: 10 feet for a crawl space or slab, 20 feet for a basement. If you are still deciding between a basement, a crawl space or a slab, that is 10 extra feet of separation your site plan has to find.
• Tank to the foundation and to the property line: 5 feet each.
• Well to the property line: 5 feet, and to a neighbor’s well in separate ownership: 25 feet. On a one-acre lot with neighbors on two sides, your neighbors’ septic systems constrain your well as much as your own does.

Stack those up on a small parcel and the free space collapses fast. On a one-acre lot you are placing a well, a tank, two full drainfield areas, a driveway, the house and usually a shop, with a 100-foot circle around the well that nothing wastewater-related can enter. This is why I want the septic site evaluation done before the house gets sited, not after. Reversing that order is the most expensive sequencing mistake I see on rural lots, and it is the reason the septic evaluation sits near the top of the order of operations when you prepare land to build a house.

One more trench detail that nobody bids by accident: Idaho amended the plumbing code to require buried yard piping to be at least 42 inches below grade. Teton County’s frost depth is 32 inches, so the plumbing rule is ten inches deeper than frost. Every foot between your tank and your drainfield, and between your well and your house, gets dug to the deeper number.

What does the permit process cost and how long is it good for?

The state writes the rules, but the seven public health districts issue the permits, do the site evaluations and inspect the installation. For Teton, Jefferson, Madison, Bonneville, Fremont, Clark, Custer and Lemhi counties, that is Eastern Idaho Public Health. Their published fees as of this writing:

Item	Fee
Individual system permit (new, expansion or repair)	$900
Central / large soil absorption system permit	$3,000
Tank only or vault privy permit	$450
Speculative site evaluation	$450, creditable toward the permit fee if requested within a year
Permit renewal	$50

Those are the health district’s fees only. They are not what the system costs to build, which is tank, pump, panel, sand, pipe, gravel, excavation and backfill, and on an engineered septic system also the designer’s fee. The install number swings more with soil and system type than almost any other site line item, which is why it sits in the same budget conversation as well drilling. I keep the dollars for that in the well and septic cost guide rather than restating them here, and the broader site-cost picture lives with the hidden costs of building a custom home.

Two process facts worth planning around. The permit is valid for two years and renewable for $50, so pulling it very early in a long design process can mean renewing it.

Nothing gets processed without a scaled plot plan and building plans in the application. That is a real dependency. You cannot permit the septic until the house is far enough along to show bedroom count and footprint, and you cannot finalize the house position until you know where the septic can go. Running those two in the right overlapping order is a scheduling problem, and getting it wrong is how a build loses a construction season. If you are watching the calendar, it ties directly into when you need to start to be dried in before winter.

Also worth knowing: Idaho lets a homeowner install their own system, but only if it is a standard or basic alternative system. A complex system requires a permitted complex installer. So the moment your lot pushes you into an engineered septic system, the do-it-yourself path closes.

Where septic plans go wrong on rural lots

After twenty years of these, the failures repeat:

Buying the lot before the test pit. This is the big one. A septic site evaluation is cheap, it is available on a speculative basis before you own the ground, and in Eastern Idaho the health district’s fee for it is creditable toward your permit. Spending $450 to learn that a lot needs a sand mound is the best money in the whole process. Skipping it and finding out later is how a lot that looked like a bargain stops being one.

Testing at the wrong time of year. Groundwater is highest in spring. A pit dug in September can read beautifully and still have seasonal high water a few feet down. The specialist knows how to read soil mottling for that, but it is a reason to take the evaluation seriously rather than treating a dry hole as a pass.

Designing the house first. Bedroom count sets your design flow, and design flow times your soil group sets your drainfield size. Draw a five-bedroom floor plan before anyone tests the dirt and you may be redrawing it.

Forgetting the replacement area is permanent. It is not a suggestion and it is not reclaimable later. I have seen homeowners pave over a replacement area for RV parking and create a problem that only surfaces years on, when the original field needs replacing and there is nowhere legal to put it.

Treating the pump as free. An engineered septic system with a pump needs a circuit, a panel location, an alarm somebody will actually hear, and power when the grid is down. Those are decisions, and they are cheaper made during electrical panel planning than after drywall.

Assuming the well and the septic are separate projects. They are one geometry problem. The well has to clear your septic and your neighbors’, and your septic has to clear your well and theirs. Decide them together, and settle the water side at the same time you are thinking about well yield and water pressure.

Who handles all of this on a SwagerBuilds build?

We do. You are not sent off to assemble a team.

On a SwagerBuilds project, the septic site evaluation is scheduled as part of the design agreement work, before the house is sited. We coordinate the test pit with the health district, bring in the designer or engineer when the soil says we need one, and we hold the engineering relationships that make a stamped design a phone call instead of a search. The plot plan and building plans that the permit application requires come out of our own plan development, so the septic application is not waiting on an outside firm’s calendar. Then we carry the permit, the install and the inspection through construction, and the system’s documentation ends up in the package you get at closeout.

That sequencing is the point. An engineered septic system is not a bad outcome. It is a solved problem on a lot of excellent building sites in Teton Valley and Eastern Idaho, and it is a routine piece of a custom home here. What costs people money is finding out about it late, after the lot is bought, after the floor plan is set, after the driveway is graded through the replacement area.

Construction on the Idaho side starts at $400 per square foot and goes up, measured on conditioned square footage, with site work like well and septic budgeted separately. On the Wyoming side, Jackson Hole starts at $1,000 per square foot and goes up. Design is sold as a fixed design fee, quoted per project, and it is the stage where this septic question gets answered rather than assumed.

If you own a lot, or you are about to buy one, the useful next step is small: get a septic site evaluation before you commit. If you want me to look at the parcel with you first, call (208) 520-0636 or get in touch here. I would rather tell you a lot is hard before you own it than after.

Built different. Built right. Built by SwagerBuilds.

Septic questions I get asked most

How do I know if I need an engineered septic system before I buy a lot?

Order a speculative site evaluation from the health district before closing. In Eastern Idaho Public Health’s territory that is a $450 fee and it is creditable toward your permit fee if you request the credit within a year. A specialist reads a test pit on the actual parcel and assigns your soil design group, which is what decides whether a standard gravity drainfield is permitted. No desk review, satellite photo or neighbor’s experience substitutes for it.

What is the difference between a standard and an engineered septic system?

A standard system is a tank, an effluent sewer and gravel trenches that distribute by gravity, sized straight from the tables in Idaho’s rules. An engineered septic system is designed for your specific site because one of those table limits is missed: not enough soil above groundwater or bedrock, soil that is too tight or too coarse, too much slope, or too much flow. It usually carries a professional engineer’s stamp and usually involves a pump, a control panel and an alarm.

How big does my drainfield have to be?

Take your design flow and divide by your soil’s application rate. Idaho sizes a three-bedroom dwelling at 250 gallons per day and adjusts by 50 gallons per bedroom from there, and the application rates run about 1.0, 0.5 and 0.2 gallons per square foot per day for soil Groups A, B and C. Then double the result, because the rules require room for two complete drainfields, each sized for the full flow. A four-bedroom house on Group C soil commits roughly 3,000 square feet of yard.

How far does a septic drainfield have to be from a well in Idaho?

100 feet between a drainfield and any well or domestic water supply, rising to 300 feet for a drainfield over 2,500 gallons per day. The septic tank itself needs 50 feet from a private well and 100 feet from a public supply, and the effluent pipe needs 50 feet. Those distances apply to your neighbors’ wells and drainfields too, which is what makes septic layout tight on smaller parcels.

Can I install my own septic system in Idaho?

Only if it is a standard or basic alternative system. A complex system, whether that is pressure distribution, a sand mound, a sand filter, an evapotranspiration bed or a packaged treatment unit, must be installed by a permitted complex installer. So if your soil pushes you into an engineered septic system, self-installation is off the table regardless of your own skills.

TL;DR: A backup generator on a rural Idaho lot is not really about the average outage, because the average outage here is short. It is about the eight-hour February one that drops the well pump and the heat at the same time. Size it around the loads that fail badly, pick the transfer switch before the generator, and know that Idaho’s electrical code says almost nothing about any of it.

Do you actually need a backup generator in Teton Valley?

Start with the honest number, because most backup generator sales pitches skip it. Fall River Rural Electric Cooperative, which serves most of Teton Valley, reports a 2022 average outage duration of 165 minutes per member, against an average of more than 500 minutes for Idaho electric utilities that year. Its own five-year figure for 2018 through 2022 is under 300 minutes per member, which it describes as a little over 24 minutes a month. The co-op runs 25 substations. By utility standards that is a good record, and it excludes major weather events and wholesale supply problems.

Nationally the picture is similar in shape. The U.S. Energy Information Administration reported that American customers averaged 11 hours without power in 2024, but nearly nine of those hours came from major event days, which is 80 percent of the total. Interruptions outside major events routinely average about two hours a year.

So the case for a backup generator is not the two hours. It is the tail. A handful of hours a year, concentrated in one or two bad storms, in a place where the storms land in January and the lots are at the end of long rural feeders. The question is not how often the power goes out. It is what breaks when it goes out for eight hours at ten degrees.

That is a different question for a house on a well than for a house in town, and it is why I treat a backup generator as a rural-lot decision rather than a luxury upgrade. If you are still choosing a parcel, it belongs in the same conversation as well and septic cost and the rest of what it takes to prepare land to build a house.

What a backup generator has to carry in a rural house

In town, an outage is an inconvenience. On a well, with no gas main, an outage takes your water, your heat, and sometimes your sewer in the same minute. That is the list worth protecting, and it is shorter than people expect.

The loads that actually matter in a cold-climate Idaho house:

• The well pump. No power, no water, and no water means no flushing and no refilling a boiler. Pump starting current is the single biggest surge most houses have. We cover pump and pressure-tank sizing in detail in will my well give the house enough water pressure.
• Heat. A gas furnace needs maybe 600 watts to run its blower and controls. A boiler needs its circulators. A heat pump needs real amperage, and a cold-climate heat pump needs it on exactly the night you are losing power.
• Freeze protection. This is the one that turns an outage into a claim. Pipes in an unheated bay, a hose bib, the slab edge in an unheated garage. A house that loses heat for a day in February can cost more to repair than the generator.
• A septic lift pump, if the lot needs one.
• Refrigeration, a few lights, internet, and the garage door. Small loads, high quality-of-life return.
• Fresh air and filtration. If the outage happens during smoke season, the whole house ventilation fan and the air filtration in front of it are worth keeping alive.

Notice what is not on that list: the range, the dryer, the hot tub, the car charger, and the second oven. Those are the loads that drive a generator from 14 kW to 26 kW, and they are the loads you can live without for eight hours. That single distinction is most of the sizing conversation.

Three ways to size a backup generator

There are only three honest approaches, and the one you choose decides the generator, the switch, and the fuel tank all at once.

Approach	What it powers	Transfer equipment	What sets the size	Fits
Essential circuits	Well pump, heat, fridge, some lights and outlets, internet	Small manual or automatic switch feeding a subpanel	The well pump’s starting surge, plus the heating system	A house with a gas or propane furnace and a modest well; the lowest-cost path that still protects the house
Load-managed whole house	Everything, but not all at once. Electronics shed the big loads in sequence	Service-rated automatic switch plus load-management modules	The largest combination the controls will ever allow at one time	Most of the custom homes we build. You get normal life on a smaller machine
True whole house	Everything, simultaneously, with nothing managed	Service-rated automatic switch sized to the service	The full calculated load of the house	All-electric houses, heat pumps plus EV charging, or an owner who does not want to think about it

Load management is the move most people should make and most people have never heard of. Instead of buying a generator big enough to start the heat pump, the oven, and the dryer in the same second, you buy a smaller one and let the controls decide the order. The dryer waits. Nobody notices.

Two things matter more than the kilowatt number on the lid. First, surge. A well pump or a compressor draws several times its running current for a moment at startup, so a generator that comfortably carries the running load can still stall on the start. Soft starters and electronic load control are often cheaper than the next size up. Second, derating for altitude. Teton Valley floor sits around 6,100 feet and the benches run higher. Naturally aspirated engines lose output with altitude, so a machine rated at sea level does not deliver its nameplate here. Ask your installer for the altitude-corrected rating in writing, not the brochure number.

Manual switch, interlock kit, or automatic transfer switch?

Pick the transfer equipment first. It decides how the house behaves at 2 a.m. when nobody is awake to notice the power went out, and it is the part that keeps a lineman safe.

Whatever you choose, the job is the same: it has to be impossible to connect the generator and the utility to the house at the same time. Backfeeding a de-energized line is how people get killed, and code treats that as the whole point of transfer equipment, not a feature of it. Never run a generator into a dryer outlet or a “suicide cord.” If a contractor offers that, you have learned something useful about the contractor.

Option	How it works	Who acts	Watch out for
Generator interlock kit	A sliding plate in the main panel physically prevents the main breaker and a generator breaker from being on together	You, by hand: kill the main, start the generator, flip the generator breaker, then shed loads yourself	Must be a kit listed for that exact panel. You are the load management, so the discipline has to be yours
Manual transfer switch	A separate switch feeding a dedicated subpanel of chosen circuits	You, by hand, but the circuit selection is already decided and labeled	Only the circuits in that subpanel are covered. Decide them during design, not after drywall
Automatic transfer switch (load side)	Sits downstream of the service and switches a subpanel or the whole panel automatically within seconds	Nobody. It senses the outage, starts the generator, and transfers	Adds a box and a second set of conductors. Needs a maintained exercise schedule to stay reliable
Service-rated automatic transfer switch	Replaces the service disconnect, so utility power and generator power both land in one listed enclosure	Nobody	Cleanest install on new construction, but it has to be planned with the meter and service layout, not retrofitted later

On a new build the service-rated automatic switch is usually the right answer, for an unglamorous reason: we are already setting the meter, the service conductors, and the panel, so making the transfer switch part of that assembly costs far less than adding it as a second enclosure after the fact. It also means the generator is sized and the panel is sized in the same conversation, which is the point of the electrical panel and service capacity discussion we have before the slab goes in.

One manufacturer detail worth knowing, because it changes the sizing math: an automatic switch can be told to lock out a single large load. Generac, for instance, lists an auxiliary transfer switch contact kit for exactly that, and notes it is not compatible with their 50-amp pre-wired switches. That one accessory sometimes saves a whole size class of backup generator.

What Idaho’s electrical code says about generators, and what it skips

This is the part nobody tells you, and it is the most useful thing in this post.

Idaho’s electrical rules live in IDAPA 24.39.10, the Rules of the Idaho Electrical Board, administered by the Idaho Division of Occupational and Professional Licenses. Section 600.01 adopts the 2023 National Electrical Code and then amends it, item by item, from (a) through (hh). That is 34 state amendments to the national code.

I read all 34. Not one of them mentions generators, standby power, or transfer switches.

That matters in both directions. It means Idaho has not softened anything about backup power, so NEC Article 702, which governs optional standby systems, applies to your house exactly as written. And it means the state has added no local requirement either: no mandated size, no required transfer switch type, no rule that a new rural house be generator-ready. The design is entirely your builder’s and your electrician’s call, which is also true of the filter in your furnace and, as we found earlier this month, of several other things Idaho leaves open.

Idaho’s amendments do touch the neighborhood of this work. Amendment (k) narrows arc-fault protection in one- and two-family dwellings to bedroom circuits only. Amendments (o) and (r) allow emergency disconnects on one- and two-family dwellings, which is relevant to how your service and a service-rated switch get arranged. Amendments (gg) and (hh) address energy storage: systems must be listed, except lead-acid batteries, and in one- and two-family dwellings the disconnect or its remote control must be readily accessible. If you are weighing a battery instead of a generator, those two are the Idaho-specific rules that apply to you.

From the national code, the one requirement that actually shapes your quote is the capacity rule. Under the 2023 NEC, if the generator picks up the load automatically, the system has to either supply the full load that gets automatically connected, or have capacity sufficient for the maximum load that an energy management system will connect. In plain terms: you may not wire an automatic switch to more house than the generator can carry and hope nobody runs the dryer. If you want a smaller generator on an automatic switch, the load shedding has to be engineered in, not left to the homeowner’s judgment. With a manual switch the user selects the loads, which is why interlock kits and manual switches are allowed to be simpler.

The permit side is specific and easy to get wrong. Under Section 500 of the same rule, electrical permits must be purchased before work commences, the permit holder must request an inspection, no wiring or equipment may be concealed from sight until it has been inspected, and a permit expires 365 days after purchase. The rule also sets an existing-dwelling-unit permit at sixty-five dollars per inspection. So if you are adding a backup generator to a house you already own, that is a permitted, inspected job with a published fee, not a weekend project. On a new build it folds into the electrical permit we are already pulling, and the generator circuit gets inspected along with everything else. What gets inspected and when is worth reading if you have not been through it.

Propane, natural gas, or diesel on a Teton Valley lot

Fuel choice is usually decided for you by the lot, not by preference.

Natural gas is the easiest fuel to live with, because the backup generator never needs refilling and there is no tank to site. It is also unavailable on most of the rural lots we build on. If a gas main runs to your parcel, use it.

Propane is the default for a rural Idaho custom home, and it has a quiet advantage: most of these backup generators make more power on propane than on natural gas. Generac’s published spec sheet for the 26 kW Guardian rates it at 22,500 watts on natural gas and 26,000 watts on propane. Same machine, same pad, 3.5 kW of difference. If you are sizing near a threshold, the fuel changes which side of it you land on.

Diesel makes sense when you need a big machine, a long unattended run, or a unit that is not dependent on a gas regulator in the cold. It costs more up front, needs the fuel kept fresh, and is the loudest of the three. For a house, propane usually wins.

Two propane details that get skipped on rural installs. First, the tank has to be sized for vaporization, not just for volume. A propane tank has to boil liquid into gas to feed the backup generator, and how fast it can do that depends on how much tank wall is in contact with liquid and how cold it is outside. A tank that holds plenty of fuel can still fail to deliver enough gas on a ten-degree morning if it is too small or too empty. That is why a backup generator on a Teton Valley lot gets a 500- or 1,000-gallon tank, not a pair of cylinders, and why your propane supplier should size the tank and the regulators for the backup generator’s peak demand in winter conditions. Second, plan the tank location with the driveway. A tank the truck cannot reach in February is a tank that does not get filled in February, which is the same month you will want it.

How long will a 500-gallon propane tank run a backup generator?

You can do this arithmetic yourself, and you should, because it is the number that tells you whether your plan survives a real storm.

From the same manufacturer spec sheet, the 26 kW Guardian burns 2.06 gallons of propane per hour at half load and 3.63 gallons per hour at full load. Propane tanks are filled to about 80 percent, so a 500-gallon tank holds roughly 400 usable gallons and a 1,000-gallon tank roughly 800.

Tank	Usable propane (at 80%)	Runtime at half load	Runtime at full load
500 gallon	about 400 gallons	about 194 hours, roughly 8 days	about 110 hours, roughly 4.5 days
1,000 gallon	about 800 gallons	about 388 hours, roughly 16 days	about 220 hours, roughly 9 days

Three honest caveats. That tank is also feeding your furnace, your water heater, your range and your fireplace, so backup generator runtime competes with heating. The tank is rarely full when the storm arrives. And a backup generator sized with load management spends most of an outage well under half load, which stretches those hours considerably. The point of the table is not the exact figure. It is that a correctly sized propane install buys you days, not hours, and that is a different category of protection from a portable unit and a gas can.

Multiply gallons per hour by your own delivered propane price to get the cost of running it. I am not going to publish a fuel price that will be wrong by spring.

Where the generator goes, and what it sounds like

Siting is a design decision, and on a snowy lot it is not a small one.

The manufacturer’s listing governs clearance. The 26 kW Guardian is listed and labeled for installation as close as 18 inches to a structure, and the spec sheet directs that it be located away from doors, windows and fresh air intakes and in accordance with local codes. Combustion engines make carbon monoxide, so that second sentence is the one that matters. Keep it away from openings, away from where the dog sleeps, and off the path of a bedroom window.

Noise is real but overstated. The same sheet lists 67 dB(A) at 23 feet under normal load, and 57 dB(A) at 23 feet during its low-speed weekly exercise. Conversation is around 60. Your neighbors will hear it on the one night it runs; you will barely hear the Tuesday self-test.

Then the Idaho part. The pad has to sit above where the snow piles and where the roof dumps, because a backup generator buried in a drift cannot get combustion air and an air-cooled unit that cannot breathe shuts down. Keep it out from under eaves that shed, which is the same reasoning behind how we detail roofs to prevent ice dams, and plan for the snow load the site actually gets. Leave yourself a path to shovel to it. And since the whole point is that it runs when you are not there, put it on monitoring, which is one of the few smart home features that pays for itself: a backup generator that failed its self-test in November and told nobody is not backup power.

Wildfire season adds one more reason to care. In smoke and fire conditions, utilities across the West de-energize lines on purpose, and that kind of outage is planned, regional, and long. If the lot is in that exposure, read this alongside how we approach a wildfire resistant home.

Is a battery better than a backup generator?

Sometimes, and it depends almost entirely on how long your outages are and whether the house is all-electric.

	Propane standby generator	Home battery
Runtime	Days, limited by the tank	Hours for the whole house, longer on essential circuits only
Refuel	Propane truck	Grid, or solar if you have it and the sun is out
Cold weather	Runs; needs a correctly sized tank and a cold-weather kit	Capacity and charge rate drop in the cold unless the enclosure is conditioned
Startup surge	Handles a well pump well, especially on propane	Depends on the inverter rating; a deep well pump can be a problem
Noise and emissions	About 67 dB(A) at 23 feet; combustion, so siting matters	Silent, no exhaust, can sit in a garage
Maintenance	Oil, filters, a weekly exercise cycle, annual service	Essentially none, with a finite cycle life
Idaho code note	No state amendment addresses it; NEC 702 applies as written	Must be listed except lead-acid, and the disconnect must be readily accessible

For a house on a well in Teton Valley, the backup generator is usually the better single answer, because a long winter outage is the scenario you are buying for and days beat hours. The combination is better still, and increasingly common on all-electric builds: battery for the quiet two-hour outages that make up most of the count, backup generator for the rare multi-day event. Just do not buy both to hedge a decision nobody has made yet. Pick the scenario first.

What drives the cost

I am not going to publish a backup generator price here, because the installed number swings more with site conditions than with the machine, and a stale figure is worse than none. What I can tell you is exactly what moves it:

• Backup generator size, which is driven by the sizing approach you chose above, not by the square footage of the house.
• Transfer equipment. An interlock kit is a fraction of a service-rated automatic transfer switch. This is usually the largest single swing.
• Load management modules, if you are going smaller on purpose.
• Fuel. Tank purchase or lease, the gas line, the regulator, and the excavation to set the tank where the truck can reach it.
• Distance. Trenching from the backup generator to the panel, priced by the foot, and rock makes it worse.
• The pad and the electrical work, including any service changes.
• Permit and inspection. Published and modest. Idaho’s rule sets an existing-dwelling-unit electrical permit at sixty-five dollars per inspection; on new construction it rides along with the electrical permit already in the budget.

The real lever is timing. Every one of those line items is cheaper while the trenches are open and the service is being set than it is after the driveway is poured. Making a house generator-ready during construction, a conduit stub, a pad location, the tank sized with the generator in mind, a transfer switch planned into the service, costs very little and preserves the option. Adding it in year three means opening ground twice.

For how pricing works on our side of it, SwagerBuilds starts at $400 per square foot and goes up in Teton Valley and eastern Idaho, and starts at $1,000 per square foot and goes up in Jackson Hole, with a fixed design fee quoted per project. Backup power is scoped as part of the electrical package, not sold as an add-on after the fact. If you want the broader picture first, start with what it costs to build in Teton Valley.

How we handle backup power on a SwagerBuilds build

Twenty years in construction has taught me that the backup generator conversation always happens. The only variable is whether it happens during design, when it is cheap, or during the first February, when it is not.

So we raise it at the electrical walk, before the slab, in the same sitting as the panel and the service. I ask three questions. Is the lot on a well? Is the heat electric? And how long are you willing to be without water? Those three answers settle the sizing approach, and the sizing approach settles everything else. A propane house on a modest well with a gas furnace usually lands on a load-managed machine and a service-rated automatic switch. An all-electric house with a heat pump and a car charger lands bigger, or lands on load management plus a battery.

Then it gets built in. The pad gets located with the snow and the propane truck in mind, the conduit gets run while the ditch is open, the tank gets sized with the supplier for winter demand rather than for the generator’s brochure, and the transfer switch is part of the service assembly instead of a box bolted on later. The circuits that matter get labeled, so the house is documented rather than guessed at. And because I am involved in every phase of every build, the electrician, the propane supplier and the excavator are hearing the same plan from the same person rather than three versions of it. We also keep 24/7 cameras on every job, so you can watch the service and the pad go in from wherever you are, which matters to the clients who are managing a build from out of state.

If backup power never becomes a priority, you have lost almost nothing: a stub of conduit and a thoughtfully placed pad. That is the cheapest insurance on the whole electrical package. For how we work in general, see our process, and for the market itself, building in Teton Valley and building in Driggs.

Backup generator FAQ

What size backup generator do I need for a house on a well in Idaho?
It depends on the heating system and the pump, not the square footage. A propane- or gas-heated house protecting its well pump, heat, refrigeration and some lights is usually well served by a mid-size machine with load management. An all-electric house with a heat pump and an EV charger needs a larger unit or engineered load shedding. Get the altitude-corrected rating and the pump’s starting surge in writing before you sign anything.

Does Idaho require a permit to install a backup generator?
Yes. Idaho’s electrical rule requires that a permit be purchased before work commences, that the permit holder request an inspection, and that no wiring be concealed before it is inspected. The rule sets an existing-dwelling-unit permit at sixty-five dollars per inspection, and permits expire 365 days after purchase. On a new build it is part of the electrical permit already being pulled.

Do I need an automatic transfer switch, or is a manual one fine?
A manual switch or a listed interlock kit is fine if someone is reliably home to operate it and to keep the big loads off. An automatic switch is better for a second home, for a house with a well, or for anyone who does not want to be awake for the transfer. Under the 2023 NEC, an automatic system must either carry the full load it connects or use an energy management system sized for the maximum load it will connect, so you cannot quietly undersize an automatic install.

How long can a backup generator run on a 500-gallon propane tank?
Roughly eight days at half load and about four and a half days at full load, using a 26 kW unit’s published consumption of 2.06 and 3.63 gallons per hour and a tank filled to about 80 percent. In practice the propane is shared with the furnace and water heater, and the tank is rarely full, so treat it as a planning estimate.

Should I put in a battery instead of a backup generator?
If your outages are short and the house is all-electric with solar, a battery can cover most of them silently and with no maintenance. If you are on a well in a cold valley and worried about a multi-day winter storm, the generator is the better single answer because its runtime is measured in days. In Idaho, energy storage systems must be listed, except lead-acid, and the disconnect or its remote control must be readily accessible in a one- or two-family dwelling.

Talk it through before the slab

If you are planning a custom home on a rural lot in Teton Valley or eastern Idaho, the backup power decision is cheapest right now, before the service is set and the ground is closed. Call me at (208) 520-0636 or use the contact page and we will walk the loads, the fuel and the switch together.

Built different. Built right. Built by SwagerBuilds.

Short answer: air filtration in a new Idaho home should be a MERV 13 filter in a 4-inch or deeper cabinet at the air handler, sized so the filter is not fighting the blower. Idaho code requires a ventilation system in every new house and never names a filter rating, so the number is the builder’s call, not the inspector’s. In smoke season that choice is the whole ballgame.

Does Idaho code require air filtration in a new house?

No. Idaho requires a filter to exist in a central system, and it stops there. It never tells you how good that filter has to be.

Here is the part most people never hear. Idaho adopts the 2018 International Residential Code with its own amendments at IDAPA 24.39.30, and amendment 03.h throws out the national language and replaces it with one flat sentence: dwelling units shall be provided with whole-house mechanical ventilation in accordance with Section M1505.4. The national code only triggers that requirement if the house tests tight. Idaho removed the trigger. Every new Idaho dwelling gets a ventilation system, period. I wrote up how that sizing works in the whole house ventilation guide.

Now read those two facts together, because nobody in this market does. Your new house is required to have a fan whose entire job is pulling outdoor air inside. And not one line of Idaho’s amendments mentions filters, filtration, or MERV. I went through them. The word does not appear.

So in August, when the valley fills with smoke off a fire in central Idaho or western Montana, code has guaranteed you a machine bringing that air in and has said nothing at all about cleaning it. That gap is filled by whoever specs the mechanical system. On my jobs that is me.

The only places real numbers show up are voluntary programs. ENERGY STAR certified new homes require MERV 6 or better. EPA Indoor airPLUS and DOE Zero Energy Ready Home require MERV 8 or better. Those are floors written for the whole country, not answers for a valley that gets a month of smoke a year.

What does a MERV rating actually mean?

MERV stands for Minimum Efficiency Reporting Value. In plain English: out of 100 particles of a given size that hit the filter, how many does it catch? Higher number, more caught. The test behind it is ASHRAE 52.2, and it only scores particles between 0.3 and 10 microns.

Why that window matters: a human hair is about 70 microns. Wildfire smoke is mostly PM2.5, meaning 2.5 microns and under. Pollen and dust sit up at the big end. So a filter can be great at dust and nearly useless at smoke, and the single MERV number hides that unless you look at the breakdown. Here are EPA’s minimum efficiencies by particle size.

MERV	0.3 to 1.0 micron	1.0 to 3.0 micron	3.0 to 10 micron	What it is really for
1 to 4	not rated	not rated	under 20%	Keeping fuzz off the blower. Not air quality.
6	not rated	not rated	35% or more	ENERGY STAR floor. Big dust only.
8	not rated	20% or more	70% or more	Indoor airPLUS floor. Dust, pollen, some mold spores.
11	20% or more	65% or more	85% or more	Starts touching fine particles. Pet dander.
13	50% or more	85% or more	90% or more	Smoke, fine dust, most of what you care about.
14	75% or more	90% or more	95% or more	Better on smoke. Needs a system built for it.
16	95% or more	95% or more	95% or more	Clean-room territory. Rare in a house.

Read down the first column. Everything below MERV 11 is simply not rated for the 0.3 to 1.0 micron band, which is where smoke lives. That is the whole argument for 13 in this valley, and it is why I do not treat the ENERGY STAR floor as an answer here.

One more term, because a salesman will use it on you. HEPA is not a MERV rating. A true HEPA filter catches 99.97% of particles at 0.3 microns. It also chokes a residential blower, which is why HEPA belongs in a portable unit or a dedicated bypass, not jammed into your furnace slot.

What MERV should a new Idaho custom home have?

MERV 13, in a deep cabinet. That is my default on every house, and I will tell you exactly when I deviate.

EPA’s own guidance is to use at least MERV 13 if you are upgrading, and then to go as high as the fan and the filter slot can handle. The second half of that sentence is the one builders skip. A MERV 16 filter in a 1-inch slot is worse than a MERV 8 done right, because the system cannot move air through it and you end up with a cold bedroom, a short-cycling furnace, and a blower motor that dies early.

Where I go up: a client with a documented sensitivity, or a house sited low in the valley where smoke settles and holds. Then I look at 14, and I size the cabinet and the return for it from the start rather than bolting it on.

Where I stay at 13 and spend the money elsewhere: almost always. Thirteen in a 4-inch cabinet, with return ducts sized to keep the air moving slowly through it, outperforms a higher number squeezed into a system that was never drawn for it. The filter is one line on the mechanical plan, and the plan is where this gets won or lost. That coordination happens during the design phase, before anybody signs a construction number.

Why does a 1-inch filter choke a brand-new furnace?

Because air has to be pushed through it, and pushing costs pressure. The filter is typically 20% to 50% of the total pressure drop in a residential system, per the Department of Energy’s Building America guidance on high-MERV filters. That is one component eating up to half your budget.

The budget is small. Most residential systems want total static pressure no higher than 0.4 to 0.5 inches of water column. A standard PSC blower motor starts losing airflow around 0.5. An ECM motor is happiest between 0.3 and 0.5 and will keep straining past that, which is how you get a burned-out motor in year six instead of year twenty.

Now the numbers that settle the 1-inch argument. Same manufacturer, same MERV 7 media, measured at 300 feet per minute:

Filter depth	Pressure drop at 300 FPM	Share of a 0.5 in. w.c. budget
1 inch	0.20 in. w.c.	40%
2 inch	0.13 in. w.c.	26%
4 inch	0.12 in. w.c.	24%

Nothing changed but thickness, and the 1-inch filter costs you almost twice the pressure. The reason is surface area. A 4-inch pleat gives roughly twice the media area of a 2-inch pleat, so the same volume of air crawls through instead of being forced through. The target face velocity is 200 to 400 feet per minute, with 500 as the hard ceiling.

And here is the fact that kills the usual objection. A high MERV rating does not automatically mean high resistance. Filter design and area matter more than the number. A 4-inch MERV 12 runs about 0.2 in. w.c. at 300 FPM, which is the same as that 1-inch MERV 7. You get five MERV steps for free by making the filter bigger.

This is also why the fix is never “just buy a better filter at the hardware store.” If the slot is 1 inch, a MERV 13 in that slot is a compromise. The real fix is a cabinet, and cabinets get installed at mechanical rough-in, not after you move in.

What is a media filter cabinet, and do I need one?

A media filter cabinet is a sheet-metal box built into the return duct right before the air handler, deep enough to hold a 4-inch, 5-inch, or thicker filter instead of the 1-inch slot that comes stamped into the equipment. It is the single highest-value piece of air filtration hardware in a house, and it costs almost nothing when it goes in during construction.

What it buys you, in order of how much the client notices:

• You can actually run MERV 13. The depth gives you the media area to do it without strangling the blower.
• Filter changes drop from monthly to quarterly. More media means more loading capacity before pressure climbs. DOE guidance is roughly every three months on a normal house.
• The blower lasts. Lower static pressure for the life of the equipment.
• It seals. A proper cabinet has a gasketed door. A 1-inch slot usually leaks air around the filter frame, which means a share of your air never gets filtered at all. That bypass leak is the quiet reason a good filter underperforms.

The one thing it costs you is space. A deep cabinet plus service clearance needs a real mechanical room, not a closet somebody found after the floor plan was done. That is a design decision, and on my jobs we make it while the plans are still on the screen.

If you want more area without a deeper cabinet, the other move is a return box that holds two filters side by side, or simply a physically larger filter. Both need the duct drawn that way from the start. Retrofitting either one into a finished house means opening ceilings.

Does a better filter help with wildfire smoke?

Yes, and in this valley that is the main reason to spend the money. Smoke is the one air-quality problem here that is severe, annual, and completely outside your control.

Wildfire smoke is dominated by PM2.5, particles 2.5 microns and smaller, and a good share of that mass sits down in the 0.3 to 1.0 micron band. Go back to the MERV table. A MERV 8 filter has no rated efficiency in that band at all. A MERV 13 catches at least half of it on every pass, and a house recirculating its air several times an hour gets a lot of passes.

EPA’s own wildfire indoor air quality guidance says the same thing in homeowner terms: keep windows and doors shut, set the system to recirculate, use a MERV 13 filter if possible, run a portable air cleaner that does not produce ozone, and stop adding particles indoors by cooking, burning candles, or lighting the wood stove during a smoke event.

Three things I would add from working through smoke seasons here.

Your fresh-air intake needs a plan. Code gave you a ventilation system that runs on a timer. During a bad smoke stretch you want to be able to shut it down or switch to recirculation without climbing in the attic. That means a control the homeowner can reach, specified at rough-in, not a dip switch inside the unit.

Keep spare filters. A smoke week loads a filter like a normal month. Buy them in the spring, before the valley buys them out in August.

The envelope does half the work. A leaky house pulls smoke through every gap regardless of what is in the filter cabinet. Air sealing and insulation detail are part of your air filtration strategy whether anybody calls it that. Same for the water-resistive barrier and the windows.

Smoke season is one piece of a bigger pattern. If you are new to the area, read what the Eastern Idaho climate does across a full year and how I build for wildfire. Idaho DEQ publishes the monitoring data and issues the advisories.

Does my HRV or ERV need its own filter?

Yes, and this is where I see the most expensive mistakes.

An HRV or ERV is a second air path into your house that does not necessarily go through the furnace filter. If the unit is ducted independently, outdoor air enters through whatever filter came in the box, which on a lot of units is a washable screen or a low MERV panel. You can have a beautiful MERV 13 cabinet on the furnace and a separate fan quietly delivering unfiltered August air to your bedrooms.

How the ventilation is ducted	Where the air filtration happens	What I check
Fresh air dumped into the furnace return, upstream of the cabinet	The main MERV 13 cabinet handles everything	Blower has to run for ventilation to be filtered. Verify the control logic.
HRV or ERV fully ducted on its own supply and return	Only the unit’s own filters	Can the unit take a higher MERV cartridge, and what does that do to its rated airflow?
Exhaust-only ventilation	Nowhere. Makeup air comes in through leaks.	Not something I spec on a custom home here.

My preference on a Teton Valley house is an ERV with a filter cartridge on the outdoor-air side that I can upgrade, plus the MERV 13 cabinet on the air handler. Two stages, and the smoke has to get through both. The tradeoff is that higher-MERV cartridges cut the unit’s rated airflow, so the unit has to be selected a size up front. Again: a plan decision, not a field decision.

The sizing math and the HRV-versus-ERV call are in the ventilation post. Short version for a cold dry climate like ours: an ERV, because cold air is dry air and you do not want to haul the indoor humidity out all winter.

What does air filtration cost to put in and keep running?

In a new build, the hardware is a rounding error and the operating cost is real but small. The expensive version is the one you retrofit.

These are market figures, not SwagerBuilds pricing. They come from a May 2026 HVAC cost survey and are national, so read them as orders of magnitude.

Item	Market range	Typical
Whole-house media filter cabinet, installed	$250 to $1,800	$500 to $900
Custom cabinet or retrofit into finished ductwork	$400 to $2,000	$900
Stepping media from MERV 8 to 11 up to MERV 13 to 16	adds $50 to $400	per filter
Replacement filter, 4-inch or deeper media	$30 to $300 each	$95
Annual filter spend, normal house	$120 to $250	two to three changes
Annual filter spend, pets plus a hard smoke season	about $380	four changes

What is not in those numbers: the duct and return sizing that lets a deep filter work, the mechanical-room square footage, the homeowner-reachable ventilation control, and the ERV cartridge upgrade. On a custom home those are design and coordination items, not line items you buy at a counter. They are also the difference between a system that performs and a box full of expensive filters.

For what the whole house runs, construction on a SwagerBuilds home in Teton Valley or Idaho starts at $400 per square foot and goes up. The breakdown is in the Teton Valley cost post and the Idaho cost post. Design is a fixed design fee, quoted per project.

Do I need a whole-house purifier, a UV light, or an ionizer?

Usually no, and I will not sell you one. A correctly sized MERV 13 in a deep cabinet does most of the work that these add-ons promise, at a fraction of the price and with no moving parts.

The honest breakdown:

• Portable air cleaners. These are genuinely useful, especially in a bedroom during a smoke event. EPA treats them as a real tool and specifically says to pick one that does not produce ozone. Buy one sized for the room, not the house.
• UV lights in the ductwork. Aimed at microbes on the coil, not at particles. They do nothing for smoke or dust. Not on my standard spec.
• Ionizers and electronic air cleaners. Some generate ozone as a byproduct, and ozone is a lung irritant. If a contractor cannot hand you third-party test data on ozone output, that is your answer.
• Whole-house HEPA bypass. Real technology, real cost, real ducting. It makes sense for a client with a documented medical need. For everyone else the money goes further in the envelope.

If you want to go deeper on what a portable unit can and cannot do, EPA’s guide to air cleaners and filters in the home is the straight version, and it leads with the thing nobody selling equipment leads with: fix the source first, ventilate second, filter third.

What air filtration will not fix

A filter catches particles. That is the entire job description. Four things in a new house that air filtration does not touch.

Radon. It is a gas that comes up out of the ground, and no filter in your furnace does anything to it. That is a sub-slab system, roughed in before the concrete goes down. Two out of five Idaho homes test above the EPA action level, which is why I rough in a passive system on every house. The full story is in the radon post, and the foundation choice interacts with it, covered in basement versus crawl space versus slab.

Combustion gases. Carbon monoxide is a gas. Detectors and correct venting handle it. A filter does not.

Off-gassing from new materials. A new house smells like a new house because of what is in the cabinets, the glues and the finishes. Standard filter media does not remove those compounds. Choosing low-emission materials and running the ventilation system handle it, and the smell fades over the first months.

Humidity. Winter here is cold and dry, and a filter has no opinion about moisture. That is an ERV, a humidifier, or both, decided at design.

I would rather tell you that up front than have you buy a two-thousand-dollar air cleaner expecting it to solve a radon reading.

How I spec air filtration on a SwagerBuilds house

Twenty years in construction, and I am involved in every phase of every build, which means the mechanical plan crosses my desk before anybody orders equipment. Here is the standard I hold it to.

1. MERV 13 media, 4-inch cabinet minimum, gasketed door, located where a homeowner can reach it without a ladder.
2. Return ducts sized for face velocity in the 200 to 400 FPM range, so the filter is not the bottleneck. That is a duct-design input, calculated, not guessed.
3. Static pressure measured at commissioning. Supply plus return, with a manometer, with the filter in. If the total is over roughly 0.5 in. w.c., something gets fixed before I hand over keys.
4. ERV with an upgradeable outdoor-air cartridge, and the unit selected a size up so the better cartridge does not starve it.
5. A ventilation control the owner can actually operate during a smoke week, labeled, with the filter sizes written inside the mechanical room door.
6. Construction filters pulled and replaced before occupancy. Drywall dust destroys a filter, and the one that ran during the build does not stay in the house.

None of that is exotic. It is coordination, and it only happens if somebody owns it. We handle plan development, engineering coordination and the mechanical design in-house, so the air filtration decision gets made once, on paper, instead of three times in the field. For the broader envelope list, start with the nine energy-efficient features worth paying for, then the heat pump versus furnace call.

What to ask your builder before the mechanical rough-in

Print these. Ask them before the ducts go in, because after insulation the answers get expensive.

1. What MERV is the filter, and how deep is the cabinet?
2. What face velocity did the duct design assume through the filter?
3. Will you measure total static pressure at commissioning with the filter installed, and will you give me the number?
4. Does the fresh-air system run through the main filter, or does it have its own?
5. Can the ERV take a higher MERV cartridge, and was it sized with that cartridge in mind?
6. Where is the filter, and can I change it without a ladder?
7. Who pulls the construction filter before I move in?

If a builder gets vague on numbers two and three, you have learned something. Those are the two that separate a designed system from a pile of equipment. The same instinct applies to the electrical panel and well water pressure. Ask for the calculation, not the reassurance. More questions like these are in the final walkthrough checklist.

Air filtration FAQ

Is MERV 13 too restrictive for a residential furnace?

Not in a properly sized cabinet. The restriction comes from media area, not the MERV number. A 4-inch MERV 12 measures about 0.2 in. w.c. at 300 FPM, the same as a 1-inch MERV 7. Put MERV 13 in a 1-inch slot and yes, you have a problem. Put it in a 4-inch or 5-inch cabinet with the return sized for it and the blower never notices.

How often should I change the filter in a new Idaho home?

About every three months on a deep media filter, per Department of Energy guidance, and more often with pets, allergies, or a hard smoke season. Change it immediately if it is collapsed, damp, or making the system noisy. During the first year after construction, check it sooner, because build dust lingers.

Does Idaho require a specific MERV rating in a new house?

No. Idaho adopts the 2018 IRC with amendments at IDAPA 24.39.30, and none of those amendments mention filters, filtration, or MERV. Idaho does require whole-house mechanical ventilation in every new dwelling, with no blower-door trigger, so every new house has a system bringing outdoor air in. The filter rating on that system is the builder’s decision.

Will a MERV 13 filter keep wildfire smoke out of my house?

It removes a large share of the smoke particles that pass through it, and that is the single most effective mechanical step you can take. It is not a seal. EPA guidance pairs the MERV 13 filter with closed windows, recirculation, a portable air cleaner with no ozone output, and not adding smoke indoors. A tight, well-sealed envelope does as much work as the filter does.

Can I add a media filter cabinet to a house that is already finished?

Usually yes, if there is room at the air handler and the return duct can be opened up. Market figures for a custom cabinet or retrofit run roughly $400 to $2,000 nationally, versus a few hundred dollars when it goes in during construction. The harder problem is that retrofitting a cabinet does not fix undersized return ducts, which is the real constraint in most houses.

Want this handled before the ducts go in?

Air filtration is a thirty-minute conversation during design and a demolition job afterward. If you are planning a custom home in Teton Valley, Eastern Idaho or Jackson Hole, I will walk you through the mechanical plan before anybody orders equipment.

Call me at (208) 520-0636 or get in touch here. If you want the full picture first, here is how we build custom homes.

Built different. Built right. Built by SwagerBuilds.

Short answer: well water pressure in a new Idaho home is not something your driller hands you. It is three numbers working together: how many gallons per minute the well actually produces, how many gallons per minute the house demands at its worst minute of the day, and how much water the pressure tank can hand over before the pump has to restart. Get those three right during design and the house feels like city water. Get them wrong and you own a plumbing problem that no amount of pipe can fix later.

What actually decides well water pressure in a new house?

Four things, in this order.

Well yield. The gallons per minute your well can deliver without pulling the water level in the borehole down below the pump intake. This is a property of the ground, not of your budget. You cannot buy your way past it.

Pump capacity. How many gallons per minute the pump moves against the lift and friction it has to fight. The rule here is absolute: never set a pump bigger than the well. A pump that outruns its well will suck the water level down to the intake, gulp air, and burn itself up.

Tank drawdown. How many usable gallons the pressure tank releases between the pump shutting off and switching back on. This is what carries you through a 90-second handwashing and a toilet flush without the pump ever starting.

Pressure setting and pipe sizing. What psi the switch turns the pump on and off at, and whether the pipe between the well and the far shower is big enough that the pressure survives the trip.

I have been in construction 20 years and I am involved in every phase of every build, which means I have watched this go wrong in all four places. The most common failure is not a weak well. It is a decent well paired with a tank that is too small, so the pump short-cycles, the pressure swings while you shower, and the pump dies years early.

How much water does a custom home need at once?

Not as much as people assume in total, and more than people assume at the peak.

Total daily use for a normal household lands in the low hundreds of gallons. That is rarely the constraint. The constraint is the worst seven minutes of the morning, when two showers, a toilet, a dishwasher and a washing machine all want water simultaneously.

There are two ways the industry sizes for that peak, and they are worth knowing because they give different answers.

The fixture-count method is crude and fast: count every fixture and outlet in the house, including hose bibbs and a hot tub, and call that number your gallons per minute. A house with twelve fixtures gets a 12 gpm pump.

The peak-demand method is better. It looks at the gallons a household actually pulls in a seven-minute window. The Water Systems Council publishes the table most drillers work from, and the numbers are higher than homeowners expect.

Bathrooms in the house	Peak gallons in 7 minutes	Minimum pump size
1	45 gal	7 gpm
1.5	70 gal	10 gpm
2	98 gal	14 gpm
3 to 4	122 gal	17 gpm

Look at the bottom row. A four-bathroom custom home wants 17 gpm at its peak. That is a real number and it is the one that surprises people who were told “we hit water at 180 feet, you’re fine.”

What is not in that table: outdoor irrigation. Lawn and landscape are usually the biggest draw on the whole property, they run for hours instead of minutes, and on an Idaho lot they can also be a water-right question rather than a plumbing one. More on that below.

What counts as a good well, and what counts as a weak one?

Five gallons per minute is the rough line. At or above 5 gpm, a normal house usually needs no supplemental storage at all. Below 5 gpm, you start engineering around it. Below 1 gpm, you are building a water system that happens to include a well.

Here is why a low number is such a problem, using Penn State Extension’s example. A 1 gpm well produces about 1,440 gallons across a full day, which sounds like plenty. But peak periods last 30 minutes to two hours, and a household can pull more than 300 gallons in a two-hour morning peak. That same 1 gpm well only delivers 120 gallons in two hours. The daily total is fine. The morning is a disaster.

The other thing people miss is that the borehole itself is storage. A 6-inch well holds about 1.5 gallons for every foot of standing water, so 100 feet of water column in the casing is roughly 147 gallons sitting there before the pump even has to keep up. That is why two wells with the same gpm can behave completely differently: the deeper one with more water above the pump has a buffer, and the shallow one does not.

In Teton Valley this matters more than most places. Idaho DEQ’s assessment of the valley describes a predominantly unconfined alluvial aquifer, recharged by tributary underflow, stream seepage, irrigation and precipitation, and it notes that shallow groundwater of 10 feet or less is common in the valley, particularly where coarse gravels sit near the surface. Unconfined and shallow means the water level responds to the season. A well tested in June is not telling you what it does in a dry September.

So the honest version is this: until your well is drilled and tested, nobody knows what your well water pressure will be. What we can do during design is plan for the range, and hold the decisions that depend on the answer until we have it.

What happens if the well can’t keep up with the house?

You do not give up and you do not oversize the pump. You add storage between the well and the house, and you let the well fill that storage at whatever slow rate it can manage. A weak well does not have to mean weak well water pressure at the fixture, as long as somebody designed for it.

The standard fix is a two-pump system. The well pump runs at a rate the well can actually sustain and fills an atmospheric storage tank, usually in a mechanical room, a heated garage bay or an insulated vault. A second pump, a shallow-well or booster pump on its own pressure switch, pulls from that tank and feeds the house. The house sees the booster pump and the pressure tank. It never sees the weak well, and the well water pressure at the shower is set by the booster rather than by the ground.

Sizing the storage is straightforward. The rule of thumb Penn State Extension publishes is 100 gallons per person, so a family of five plans on 500 gallons, plus margin for whatever the house will grow into. Published guidance for low-yield wells runs roughly like this.

Well yield	2 bedrooms	3 bedrooms	4 bedrooms	5 bedrooms
5 gpm or better	None needed	None needed	None needed	None needed
3 to 5 gpm	100 gal	150 gal	200 gal	250 gal
1 to 3 gpm	150 gal	200 gal	250 gal	300 gal
0.5 to 1 gpm	200 gal	250 gal	Not recommended	Not recommended
Under 0.5 gpm	Not recommended	Not recommended	Not recommended	Not recommended

There is a second lever most people never hear about: the well itself can hold more water. Penn State’s numbers make the point cleanly. A 6-inch well with 100 feet of standing water holds about 147 gallons. A 10-inch well with that same water column holds about 408 gallons, an increase of 261 gallons. Deepening an existing 6-inch well by another 100 feet adds about 147 gallons. On a marginal lot, a wider or deeper borehole can be cheaper than a tank, a second pump and the mechanical room space to put them in.

The catch: in a dry year, a well that normally carries 100 feet of water may be down to under 20 feet of water column. Widening it then only adds about 50 gallons. In-well storage is real, but it is the first thing drought takes away.

What I will not do is let somebody sign a construction contract on a four-bathroom house with a 1 gpm well and no storage plan. That is a callback waiting to happen, and it is the kind of thing that should get settled before the foundation is poured, not after the drywall is up. Well water pressure is a design-phase decision, not a punch-list item.

What pressure should the system run at: 30/50 or 40/60?

This is the setting that decides what your well water pressure feels like day to day. Modern systems run at one of two settings. The first number is the pressure where the switch turns the pump on, the second is where it turns off.

30/50 psi is the old default. It works, it is easy on the plumbing, and it feels thin in a big house with a long run to the far bathroom.

40/60 psi is what I want on a custom home. It gives you headroom for friction loss on the way to the upstairs shower, and it makes a second-floor fixture feel like a first-floor fixture.

The number that actually matters is not at the tank, it is at the worst fixture. The target to hold is roughly 20 psi at the inlet of the highest and farthest fixture from the pump, measured while the water is running, not sitting still. Static pressure at the tank tells you almost nothing. Flowing pressure at the far end tells you everything, and it is the only honest measure of well water pressure in a finished house.

For context on how little some things need: dishwashers and washing machines want at least 10 psi at their inlet, while lawn sprinklers typically want 20 psi and sometimes up to 40. Sprinklers are the hungriest thing on most properties, which is one more reason irrigation gets designed as its own problem.

Pumps that sit far from the house, or well below it, need higher settings to deliver the same pressure at the fixture, because every foot of lift and every fitting on the way eats into it. On a big lot where the well sits 300 feet from the house, the pressure setting and the pipe size are the same conversation.

How big does the pressure tank need to be?

Bigger than whatever the cheapest bid includes.

This is where most disappointing well water pressure actually comes from, and it is the cheapest thing on the list to get right. Here is the part almost nobody tells homeowners: a pressure tank does not store its own volume. Only about 20 percent of a pressure tank’s rated capacity is usable drawdown. The rest is air charge. Penn State Extension puts real numbers on it.

Tank rated capacity	Actual usable water (drawdown)	What that buys you
42 gal	About 8 gal	A toilet flush and a handwash
82 gal	About 16 gal	A couple of minutes of a single shower
120 gal	About 24 gal	Real buffer on a multi-bath house

So the 42-gallon tank that a builder’s allowance quietly assumes holds eight gallons. Eight gallons is one toilet flush and a pot of pasta water. On a 14 or 17 gpm system, eight gallons of drawdown means the pump restarts in well under a minute of real use.

That is the whole reason tank size matters. Most of the wear on a well pump happens when it starts and stops, not while it runs. A pump that cycles twice as often wears out in roughly half the time. A larger tank is not about comfort, although you will feel it. It is about not pulling a 300-foot pump out of the ground in year seven instead of year fifteen.

On our builds I would rather put the money into an 80 or 120-gallon tank and a correctly set air charge than into a fancier fixture. The fixture is visible and the tank is not, which is exactly why the tank is where corners get cut.

Standard pump and tank, or a constant-pressure system?

A standard system is a single-speed submersible pump, a pressure switch and a pressure tank. The pump is either full on or full off, so your pressure constantly cycles between the two switch settings. You feel that as the shower getting slightly stronger and weaker on a loop.

A constant-pressure system uses a variable-speed drive. The pump speeds up and slows down to hold one pressure, so the well water pressure at a shower feels the same whether somebody is running the dishwasher or not. It also needs a much smaller tank, because the drive is doing the job the tank’s drawdown used to do.

	Standard pump and tank	Constant-pressure (variable speed)	Storage tank and booster pump
Best when	Well yield comfortably beats peak demand	Yield is adequate but the house is big or multi-story	Well yield is below peak demand
Pressure feel	Cycles between the two settings	Steady at one pressure	Steady, set by the booster
Tank needed	Large, drawdown is the buffer	Small	Atmospheric storage plus a pressure tank
Moving parts	Fewest	Drive electronics at the well or in the house	Two pumps, two controls
Field repair	Any pump outfit in the valley	Needs someone who knows the drive	More components to diagnose
Space required	Tank only	Least	Most, by a wide margin

My honest take after 20 years of these: constant pressure is genuinely better to live with, and I will not pretend it is free or maintenance-neutral. It adds electronics to a system that otherwise has almost none, and in a rural valley the question of who can service it at 9 p.m. in February is a fair one to ask before you buy it. On a large two-story custom home with a solid well, it is usually worth it. On a simple single-story with a strong well, a correctly sized tank does the job for less.

One thing that is not optional either way: the pump is an electrical load. A submersible well pump is typically a dedicated 240-volt circuit, and on a rural property it lands on the panel alongside the septic pump, the shop subpanel and whatever else the lot needs. That is a load calculation question, and it is covered in our post on what size electrical panel a new Idaho home needs.

What does Idaho plumbing code actually require?

Idaho adopts the 2015 Uniform Plumbing Code as the Idaho State Plumbing Code at IDAPA 24.39.20, Section 600, and then amends it in a long list of specific places. Four of those amendments touch a well water pressure system directly, and one of them catches people out every single time.

The buried water line has to be 42 inches down. Idaho’s amendment to Section 609.1 throws out the national “below the frost line” language and replaces it with a flat number: the cover over yard piping “must be not less than forty-two (42) inches below grade.” Teton County’s frost depth is 32 inches. So the plumbing rule here is ten inches deeper than frost depth, and the trench from the wellhead to the house gets dug to the plumbing rule, not to the frost rule. Nobody is happy to discover that with a rented excavator and the ground already closing.

Pressure above 80 psi needs a regulator. Where static pressure in the supply piping exceeds 80 psi, UPC 608.2 requires an approved pressure regulator downstream of an adequate strainer, reducing static pressure to 80 psi or less. Regulators 1.5 inches and larger do not need the strainer. An approved expansion tank goes on the cold water distribution piping downstream of each regulator.

There is a detail here that trips up sizing: once you reduce pressure, the piping downstream is sized on 80 percent of the reduced pressure, so a regulator set at 80 psi gives you 64 psi to size against, not 80. High well water pressure is a real condition on steep lots where the well sits well below the house.

The softener loop is mandatory on a lot of houses. Idaho’s amendment to Section 610.2 requires that new one and two-family residences built slab-on-grade, or that will have a finished basement at final inspection, “must have a pre-plumbed water softener loop.” The kitchen sink needs one hot soft line, one cold soft line and one cold hard line, and exterior hose bibbs intended for irrigation must be piped with hard water. Over four bathroom groups, the Table 611.4 footnote sends softener sizing to the manufacturer’s standards.

We cover why that matters on well water in our post on whether a new Idaho home needs a water softener, and the basement-or-slab decision that triggers the requirement is in basement vs crawl space vs slab.

Frost-proof hose bibbs are required, not optional. Idaho’s amendment to 603.5.7 says that in climates where freezing temperatures occur, a listed self-draining frost-proof hose bibb is required. That is every lot we build on.

A couple of smaller Idaho changes are worth knowing because they come up in bids: listed polyethylene water service and yard piping rated at a minimum of 160 psi may run inside the building with one joint using listed metallic transition fittings (605.6.2), the water hammer section does not apply to residential construction (609.10), and the pipe insulation section is deleted outright (609.11). The plumbing inspection that checks all of this is part of the sequence in our guide to what inspections happen on a custom home.

What are the well rules on a rural Idaho lot?

The well itself is governed by the Idaho Department of Water Resources, not the building department, under the Well Construction Standards Rules. These rules decide where the well can physically go, and on a tight lot they can decide the whole site plan.

Minimum separation distances from a well, from Rule 25:

Separate the well from	Minimum distance
Septic tank	50 ft
Septic drainfield	100 ft
Drainfield serving more than 2,500 gpd	300 ft (less with site investigation data)
Effluent pipe	50 ft
Sewer lines	25 to 100 ft, by type
Permanent or intermittent surface water	50 ft
Canals, irrigation ditches, temporary surface water	25 ft
An existing well in separate ownership	25 ft (50 ft for a public supply well)
Permanent buildings	10 ft
Above-ground chemical storage tanks	20 ft
Property line	5 ft

Run the math on a small lot and you will see the squeeze. A well needs 100 feet from your own drainfield and 50 feet from any surface water, the drainfield needs its own setbacks, and the house has to fit between them. On a one-acre parcel with a creek on one edge, that is not a drafting exercise, it is the thing that determines where the house sits. This is exactly the kind of constraint we work out during design rather than discovering at permit.

The construction standards themselves are specific. Casing has to extend at least 12 inches above land surface and finished grade, and a concrete slab counts as finished grade. Wells deeper than 38 feet need a surface seal extending to at least 38 feet below land surface. In the unconsolidated, unconfined formations that make up much of Teton Valley, the casing goes at least 5 feet below the water table and is sealed to at least 38 feet. Grout seals need at least 1 inch of uniform thickness in the annular space, dry bentonite needs at least 1 and 5/8 inches.

On process: a drilling permit is required under Idaho Code 42-235 before construction, and for single-family domestic wells the Director may allow a start card instead, which has to reach the Department at least two office hours before drilling begins. The driller calls the regional office at least four hours before placing any annular seal. Start cards and verbal approvals are generally not available in designated drilling-concern, critical or management areas, which is one of the first things we check on a lot.

The part you should actually care about as a homeowner is Rule 25.25: the driller must measure and record the static water level, the pumping water level and the production rate, using a pump, bailer, air-lift or other industry-accepted test of sufficient duration. That record is your well’s report card. It is the document the pump gets sized from, which makes it the document your well water pressure is ultimately built on, and it belongs in your file, not just the driller’s.

Do I have a water-right problem, or just a well?

On most single-family lots in Eastern Idaho you are drilling under the domestic exemption, which means you are not applying for a water right the way an irrigator does. That exemption has edges, and they moved recently.

Idaho Code 42-111 defines domestic purposes two ways. The first covers homes, camps, campgrounds and livestock, including irrigation of up to one-half acre of land, as long as total use does not exceed 13,000 gallons per day. The second covers any other purpose up to a diversion volume of 2.8 acre-feet per year. The statute also excludes mobile home parks, RV parks, multi-unit apartments and condos, and primarily commercial establishments from the first definition unless they fit the 2.8 acre-foot limit, and it bars stacking multiple domestic rights to supply a use that would not qualify as domestic on its own.

Two numbers to sit with. 13,000 gallons per day is enormous for a household: a family using 400 gallons a day is at roughly 3 percent of it. But one-half acre is not much irrigated landscape at all on a three-acre or five-acre parcel. If the plan is irrigated lawn across an acre, that is the limit you will bump into first, not the daily volume.

The other edge is subdivisions. The statute treats a tract divided into five or more lots as a subdivision, with an exception for agricultural divisions where lots are five acres or larger. The legislature amended this section in 2025 and again in 2026, tightening how the exemption applies to multi-lot developments, and plats filed before July 1, 2025 are generally treated under the older rules. In some groundwater management areas, domestic wells can be limited mainly to in-home household use and stock water, with outdoor irrigation requiring a permit.

What that means practically: if you bought a lot in a newer development and the seller told you “it has a domestic well right,” that is worth verifying against the current statute and the plat date rather than taking at face value. It is a title and water question, and it is one I would rather raise before you close than after.

What does the water system cost?

I will give you market figures here and label them as exactly that. These are published national cost ranges, not SwagerBuilds pricing, and not a quote for your lot. Well costs in particular swing wildly with depth and what the drill hits.

Component	Published market range	What moves it
Submersible well pump, installed	$1,000 to $2,500	Depth, horsepower, wire run
Pressure tank replacement	$500 to $1,000	Tank size
Constant-pressure system, installed	$2,000 to $5,000	Drive, pump, controls
Pressure switch	$25 to $100	Part only
Atmospheric storage tank, 300 to 500 gal	$250 to $500	Material, freeze protection
Atmospheric storage tank, 1,000 to 3,000 gal	$500 to $1,500	Size, burial vs above grade
Electrician labor	$50 to $130 per hour	Local rates, circuit run length

What is not in that table, and the part people forget: the well itself, the trench from the wellhead to the house at 42 inches of cover, the electrical service out to the well, the wellhouse or vault if the site needs one, the pressure regulator and expansion tank if static pressure runs high, and the mechanical room floor area that storage and a booster pump occupy.

On a rural lot, water and septic together are usually one of the three biggest line items outside the house itself. Our breakdown of well and septic cost in rural Idaho covers that side, and the items that catch people are collected in the hidden costs of building a custom home.

For the house itself, our published pricing is simple and does not change by component: on the Teton Valley and Idaho side, a SwagerBuilds custom home starts at $400 per square foot and goes up. On the Jackson Hole side it starts at $1,000 per square foot and goes up. Those are construction cost on conditioned square footage, and they are fixed price after design lock. Site work, utilities, permits and landscape sit on top, which is why we price them from real numbers for your lot rather than a per-square-foot guess. The full picture is in our honest cost to build in Teton Valley.

What do we lock down during design, and when?

This is the part that separates a house with good well water pressure from a house with an expensive problem, and it is all front-loaded.

SwagerBuilds runs the whole path here. We site the well against the setback math and the septic layout, coordinate the driller and the pump outfit, carry the engineering relationships for the site and septic design, and get the mechanical room drawn large enough for whatever the well turns out to need. You are not assembling a team of specialists on your own. That work happens under a design agreement with a fixed design fee, quoted per project, before any construction price gets signed.

The sequence we work to:

1. Lot review, before you close if possible. Setbacks, surface water, drilling-concern or management-area status, plat date and water-right language, neighboring well logs.
2. Well sited on the site plan. Not a dot placed last. It drives the house position when setbacks are tight.
3. Well drilled and tested early. Static level, pumping level and production rate on paper. Everything downstream waits on this number.
4. Water system designed to the tested yield. Pump sized under the well’s capacity, tank drawdown sized to the peak, storage and booster added if the yield is short, pressure setting chosen for the house’s height and run length.
5. Mechanical room sized and drawn. Tank, softener loop, water heater and any storage, with service clearance. A 120-gallon pressure tank and a 500-gallon storage tank do not fit in a closet.
6. Water tested, not assumed. Hardness, iron and manganese are not in the standard Idaho health panel and have to be requested by name. They determine the treatment train.
7. Trench and electrical coordinated. 42 inches of cover, pump circuit on the load calculation, conduit in before the site closes.

Step 3 is the one people want to skip to save a few thousand dollars early, and it is the single worst place to save money on a rural build. Until the well is tested you are guessing at your own well water pressure, and every guess downstream compounds. Where that fits in the overall order of operations is in our steps to building a custom home in Idaho, and what gets settled and paid for in the design phase is in the design phase explained.

If you are still choosing a lot, well yield belongs on your comparison list alongside views and access. We get into that on the best lots in Driggs, the best lots in Victor, and specifically on the valley’s west side in the Packsaddle trade-off. Getting a raw parcel ready to build is covered in how to prepare land to build a house, and the other rural-lot item that shares the same soil-and-gas conversation is in radon mitigation in a new Idaho home.

Two last cross-references, because they both hinge on flow and pressure: a tankless water heater needs a minimum flow rate to fire and is unforgiving of pressure swings, so it is a poor match for a marginal well without storage. And the mechanical room that holds all of this is the same room where whole house ventilation equipment lands, which is why we draw it once, early, with everything on it.

Frequently asked questions

What is normal well water pressure for a house?
Most modern well systems are set to either 30/50 or 40/60 psi, meaning the pump turns on at the lower number and off at the higher one. On a custom home I want 40/60. The figure that actually matters is flowing pressure at the highest and farthest fixture, where you want to hold roughly 20 psi while water is running. Dishwashers and washing machines need at least 10 psi at their inlet, and lawn sprinklers typically want 20 to 40 psi.

Why does my well water pressure drop when someone else turns on a faucet?
Usually one of three things. The pressure tank’s usable drawdown is too small, so the pump restarts under light demand and pressure dips while it catches up. The pump is undersized for the house’s peak demand, so simultaneous fixtures outrun it. Or the pipe from the well or through the house is too small, so friction loss eats the pressure before it reaches the fixture. A fourth possibility on an older system is a waterlogged tank that has lost its air charge.

How many gallons per minute does a well need for a house?
Five gallons per minute is the practical line where a normal household needs no supplemental storage. Below that you engineer around it with storage and a booster pump. Peak demand, not daily total, is what sets the target: published industry guidance puts a two-bathroom house at about 14 gpm and a three to four-bathroom house at about 17 gpm at the peak. A well under 0.5 gpm is generally not considered adequate for a home at all.

How deep does the water line from the well to the house have to be in Idaho?
At least 42 inches of cover. Idaho’s amendment to Section 609.1 of the Idaho State Plumbing Code replaces the national frost-depth language with a flat minimum: the cover over yard piping must be not less than 42 inches below grade. That is deeper than Teton County’s 32-inch frost depth, so the trench is dug to the plumbing rule rather than the frost rule.

Can I fix low well water pressure after the house is built?
Some of it, yes. A bigger pressure tank, a correctly set air charge, a pressure regulator, or a constant-pressure drive can all be retrofitted. What is hard and expensive to change later is a pump sized wrong for the well, undersized pipe buried in a 42-inch trench or inside finished walls, a mechanical room with no floor space for storage, and the well yield itself. That is why we test the well and design the system before the foundation goes in rather than after.

Want this settled before you buy the lot?

If you are looking at a parcel in Teton Valley, Eastern Idaho or on the Jackson side and you want to know what the water situation really is before you commit, call me at (208) 520-0636 or get in touch here. I would rather spend twenty minutes on your well logs and setbacks now than fix a pressure problem in a finished house.

Built different. Built right. Built by SwagerBuilds.