Custom Home Build Timeline in Eastern Idaho — Month-by-Month Guide

“How long is this actually going to take?” is the second question every custom home client asks me. (The first is “how much?”) Here’s the honest month-by-month timeline for building a custom home in Rigby, Idaho Falls, Ammon, Rexburg, Shelley, or anywhere across Eastern Idaho — no shortcuts, no marketing timelines, no “we’ll be done by Christmas” that turns into next July.

National baseline for context: per NAHB’s Eye On Housing analysis of 2024 Census construction data, the average single-family home takes 9.1 months from authorization to completion — 1.4 months from authorization to start, plus 7.6 months of construction. Custom homes with real design work, real specification, and real site conditions run longer. In Eastern Idaho, expect 12-20 months from first design conversation to move-in on a typical custom project.

Months 1-2: Discovery, Design, and Feasibility

What happens: We walk your lot (or lots you’re considering), review any existing plans or sketches, understand your program — square footage, bedrooms, bath count, must-haves, finish level, budget target. If you own the lot, we pull the plat, verify setbacks and easements, check flood zone status, and confirm utility access. If you’re still lot-shopping, we help you avoid the parcels that will cost you $80K in unbudgeted site work.

Design starts in parallel. Our in-house design team takes your program to a schematic floor plan and elevation. Two to three revision rounds is normal. If you’re bringing an outside architect, we import their plans and value-engineer for buildability.

Common Month 1-2 milestones:

Signed pre-construction agreement.
Site walk and lot due diligence.
Schematic floor plan and elevation approved.
Preliminary budget range delivered.
Perc test scheduled if the lot needs septic.

Months 2-4: Selections, Engineering, and Fixed-Price Contract

This is where fixed-price gets earned. Every cabinet, tile, appliance, plumbing fixture, light, door, window, garage door, exterior stone, and finish gets picked and priced. Structural, civil, and mechanical engineering finalize. Every subcontractor scope goes out to real subs for real quotes.

Why it takes 6-10 weeks: there are typically 150+ line items in a custom home budget, and each one needs a real spec and a real price. Rushing this phase is the #1 predictor of change-order chaos later.

At the end of this window: a full construction contract with zero allowances, a complete finish schedule, and a signed number. That number does not move unless you move it.

Month 4-5: Permit Submittal and Review

Permit review times vary by county in Eastern Idaho:

Jefferson County (Rigby, Menan, Lewisville, Ririe): 2-4 weeks typical residential plan review. Submit through the county’s Planning, Zoning & Building Department (see the county’s Planning, Zoning & Building page).
Bonneville County (unincorporated, plus Ammon, Iona): 3-6 weeks. Per Idaho building permit reference data, the county uses the 2018 IRC with permit fees tiered by home valuation — a $700K custom home typically runs $4-7K all-in. As of January 2026, Bonneville County processes electrical and plumbing permits in-house.
City of Idaho Falls: 3-6 weeks. City Planning at 680 Park Avenue.
Madison County (unincorporated, plus Rexburg): 3-6 weeks.
Bingham County (Shelley, Blackstone corridor): 3-6 weeks.

If your lot needs a septic permit, plan an additional 3-8 weeks for Eastern Idaho Public Health review, depending on season and perc test scheduling. Well drilling should be booked in parallel — lead times run 4-16 weeks in Jefferson and Bonneville County during peak season.

Months 5-6: Site Work and Foundation

Once permits are issued, site work moves fast. On a typical Eastern Idaho acreage build:

Clearing, staking, and rough grade: 1 week.
Utility trenching (power, water, gas): 1-2 weeks depending on utility company scheduling.
Well drilling: booked earlier, ideally completed before excavation.
Septic install: 1-2 weeks once permit is in hand.
Excavation and foundation prep: 1 week.
Foundation pour (footings, stem walls, or monoslab): 1-2 weeks including cure time. Our concrete partner Skinner Custom Concrete handles most of our Jefferson County foundations.
Backfill and compaction: 1 week.

Weather matters. In Eastern Idaho, breaking ground November-February often means cold-weather concrete additives, heated blankets, and pour windows tied to overnight lows. We can build year-round, but scheduling smart around freeze-thaw saves money and quality.

Months 6-8: Framing, Roof, and Dry-In

Framing is the phase that visibly transforms your lot. On a 2,600-3,400 sq ft custom home:

Floor system: 3-5 days.
Wall framing (first floor, then second if applicable): 1-2 weeks.
Roof framing (trusses or stick): 3-7 days.
Sheathing, weather barrier, windows and exterior doors: 1-2 weeks.
Roof underlayment and shingles/metal: 1-2 weeks.

By the end of dry-in, the house is weather-tight. Interior work can proceed regardless of what the sky is doing. This is a huge deal in Eastern Idaho where wet Aprils and snowy Novembers can eat weeks off exposed builds.

Months 8-10: Rough-Ins (Mechanical, Electrical, Plumbing)

Once dry-in is complete, all three trades come in on a sequenced schedule:

Plumbing rough-in: 1-2 weeks.
HVAC rough-in (ducts, refrigerant lines): 1-2 weeks.
Electrical rough-in: 2-3 weeks.
Low-voltage rough-in (data, security, audio): 1 week, often concurrent.
Insulation (batt, blown, or spray foam): 1 week.
Drywall hang and finish: 3-4 weeks. This is often the longest single phase.

Multiple rough-in inspections punctuate this phase: pre-drywall electrical, pre-drywall plumbing, pre-drywall mechanical, and a framing/insulation inspection before drywall closes it up. Any inspection failure adds days, not weeks, if the builder is on their subs.

Months 10-12: Finishes

Finish work is where a lot of custom builds slip. On a fixed-price contract with selections locked, it moves cleanly:

Interior paint: 2-3 weeks.
Cabinets install: 1-2 weeks.
Countertops (template, fab, install): 3-4 weeks including 2 weeks of fabrication.
Flooring (LVP, hardwood, tile): 2-4 weeks depending on square footage and material.
Tile (bathrooms, backsplash, fireplace): 2-3 weeks.
Plumbing and electrical trim: 2 weeks.
Interior doors, trim, and hardware: 2 weeks.
Appliance install: 3-5 days.
Exterior siding, stone, and paint if not done earlier: 2-4 weeks.

Finishes stack. Cabinets have to be in before countertop template. Flooring before base trim. Paint before final electrical trim. Good schedule management here saves 3-6 weeks. Bad scheduling adds it.

Month 12-13: Final Inspections, Punch List, and Move-In

Final inspections happen in this order: final plumbing, final electrical, final mechanical, final building. Each requires a sign-off before the next. Certificate of Occupancy is issued after the final building inspection passes.

Punch list is what’s left — the touch-up paint, the cabinet drawer that sticks, the outlet cover missing, the door that needs adjustment. On a well-run build, punch is 1-3 weeks. On a rushed build, it stretches for months and clients move in with an unfinished list.

Warranty starts at Certificate of Occupancy. Idaho custom builders typically carry a one-year workmanship warranty at minimum. Ask what’s covered and how warranty calls are handled.

Total Timeline: Realistic Windows by Project Type

Entry custom, 2,000-2,600 sq ft, in-town lot with utilities: 10-14 months from signed contract to move-in.
Mid custom, 2,600-3,400 sq ft, acreage with well/septic: 13-18 months.
High-end custom, 3,400-5,000 sq ft, view lot or premium acreage: 16-22 months.
Barndominium or shop-plus-living: 8-14 months depending on scope. See our Idaho barndominium build page for details.

Add 2-4 weeks to any of the above if you’re breaking ground November-February on a build that requires significant site work.

What Actually Delays Custom Home Builds

Ranked by how often we see them cause slippage:

Client selections not made on time. Every selection you push out pushes the whole project. Fixed-price with pre-locked selections eliminates this.
Change orders during construction. A late change to floor plan or mechanical routing can cost weeks. Written change orders with real schedule impact keep this honest.
Weather during dry-in phase. Getting weather-tight before winter is the goal. Slipping into November unsheeted is a schedule killer.
Sub availability. Building without committed subs is building with fingers crossed. Real fixed-price contracts have committed subs.
Utility scheduling. Power, gas, water, well, septic — all have their own timelines. Coordination is a real job.
Inspection failures. Rare with a good crew; common with a rushed one.

Ready to Start Your Timeline?

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Prefer to talk first? Call or text (208) 520-0636. If I’m on a jobsite I’ll get back to you same day.

About the Author

Bryce Swager, Founder — 4th-generation Rigby custom home builder. BuildZoom score 94. Licensed in Idaho and Wyoming. Building fixed-price custom homes, shops, ADUs, and whole-home remodels across Eastern Idaho, Teton Valley, and Jackson Hole for 20 years.