Build

Custom Home Builder: Design & Build

Custom homes from concept through completion.

We build custom homes the whole way through — from the first sketch to the certificate of occupancy — without you ever hiring a separate designer, engineer, or six different subs. Because we keep design and construction in-house, plan production and structural engineering happen in the same shop that pours your foundation and hangs your cabinets.

A design-build home means one contract, one schedule, and one number to call. We start with a free advice visit and a complimentary 3D model so you can walk the house before we frame it. From there we handle the survey, structural engineering, energy code, and city submittal, then self-perform the trades that decide whether a house is built right: concrete, framing, plumbing, HVAC, and electrical. That vertical integration is why our schedules hold — no sub is waiting on another sub who's waiting on us.

What's included

  • Site evaluation, survey coordination, and feasibility

    Before anything is drawn we walk the lot, coordinate the survey and check setbacks, slope, utilities and access — the things that decide whether a plan fits the land and what it will cost to build there.

  • Architectural plans and structural engineering (in-house)

    Our own team produces the architectural plans and the structural engineering, so the drawings are buildable by the crew that will build them and changes don't bounce between offices.

  • Permit submittal and approval in your jurisdiction

    We prepare the complete permit package — drawings, structural calculations and energy-code compliance — submit it to your city or county and answer the plan reviewer's corrections ourselves.

  • Foundation, framing, and weatherproofing

    Excavation, footings, foundation walls, framing, roof and the weather-resistive barrier are self-performed, which is how the schedule holds through the structural phase.

  • Rough-in and finish: plumbing, HVAC, electrical

    Plumbing, HVAC and electrical rough-ins are run by our own crews and coordinated with our framers, then finished after drywall with fixtures, panels and equipment sized for the house.

  • Cabinetry, tile, flooring, and finish carpentry

    Cabinetry, tile, flooring, trim and paint finish the house, with quartz and granite countertops fabricated through our cabinetry shop and a walkthrough before the keys change hands.

How it works

  1. 1
    Free advice visit

    The builder who will price the job walks your lot or the house you plan to replace, talks through what you want and what the site allows, and leaves you with a scoped range — no obligation.

  2. 2
    Complimentary 3D model

    Every new-construction proposal includes a 3D model of the house so you can walk the rooms, check the light and move walls before anything is framed.

  3. 3
    Design and engineering

    Our in-house team turns the approved concept into construction drawings and stamped structural engineering, with the energy-code calculations the jurisdiction requires.

  4. 4
    Permits

    We submit the package, track plan review and resolve corrections ourselves, because we're the ones who will build from those drawings.

  5. 5
    Build

    One contract, one schedule, one number to call: foundation, framing, envelope, mechanical rough-ins and finishes, with our crew self-performing the trades that decide quality.

  6. 6
    Final walkthrough

    We walk every room with you against the plans and the punch list, complete the final inspections and hand over the certificate of occupancy.

The same ten-step process runs every project we build — see how we work.

What it costs

A custom home is priced per square foot at your area's build rate, then adjusted for size, finish level, site and style: smaller homes cost more per foot, Premium and Luxury finishes add to the range, and a sloped, view or well-and-septic lot adds foundation and utility work. Land, design and permit fees, utility connections and unusual soils are priced separately on every estimate.

New Custom Home cost guide

Prices as of Oct 7, 2026

StatePriced atStandardPremiumLuxury
WashingtonSeattle · 4,250 sq ft (exact)$1.41M – $1.93M$1.71M – $2.18M$1.71M – $2.18M
IdahoBoise · 4,250 sq ft (exact)$910K – $1.15M$910K – $1.15M$1.16M – $1.34M
MontanaBillings · 4,250 sq ft (exact)$730K – $925K$790K – $925K$1.02M – $1.17M
ArizonaScottsdale · 4,250 sq ft (exact)$1.3M – $1.68M$1.3M – $1.68M$1.52M – $1.78M

Planning-level ranges from our current pricing tables, standard finish at a typical size unless a column says otherwise. Land, design and permit fees, utility connections and unusual soils are priced separately.

Price my project

Timeline

  1. Design and permitting

    Concept, 3D model, construction drawings and engineering, then plan review — the length depends on the jurisdiction, and we give you a phased schedule at contract.

  2. Site work and foundation

    Clearing, excavation, footings and foundation walls; on hillside lots this phase includes retaining walls or shoring.

  3. Framing and envelope

    Floor systems, walls, roof, windows, roofing and siding — the house is dried in before the mechanical rough-ins start.

  4. Rough-ins and inspections

    Plumbing, HVAC and electrical, each inspected before insulation and drywall close the walls.

  5. Finishes and occupancy

    Cabinets, counters, tile, flooring, trim, paint and fixtures, then final inspections and the certificate of occupancy. Most single-family homes run 8–14 months from permit to occupancy; the homes on our portfolio took 8 months (Palatine, 4,254 sq ft), 10 months (Bellevue, 4,500 sq ft), 39 weeks (Aurora, 2,952 sq ft) and 7 months (Boise, 3,823 sq ft).

Permits and codes

Every new home needs a building permit, which means a complete set of architectural drawings, stamped structural engineering, energy-code documentation and often a site plan, stormwater plan and tree-protection or critical-area review depending on the lot. Plumbing, mechanical and electrical permits follow for the trades.

We handle all of it in-house: our engineering and permitting team produces the package, submits it to your city or county, answers plan-review corrections and schedules every inspection from footings to final. Inside Seattle that means SDCI; on the Eastside, City of Bellevue Development Services; in Federal Way, the Community Development Department — and the equivalent offices in Spokane, Idaho, Montana and Arizona, where we hold contractor's licenses as well.

Reviewed on Google and Yelp

What clients say

  • "Sebastian and his team did an exceptional job restoring my garage — both its structural integrity and the finish — after a car plowed into it. They prioritized the structural restoration within one day of visiting the…" Read more

    Fedon M.
    Garage Restoration · SeaTac · May 2024
    via Yelp
  • "I had a great experience with ID Builder Construction. I discovered a load-bearing beam in the house was compromised due to water damage, which would have prevented me from renting it. Sebastian came in at a reasonable…" Read more

    Nikhil A.
    Structural Repair · San Jose · Apr 2024
    via Yelp
  • "This company came out to bid and actually showed up at the date and time agreed upon. Once they quoted the work (at a competitive price) they had guys working that same day. They kept to their quote, and we even added…" Read more

    Jake P.
    Remodel & Drywall · Puyallup · Mar 2024
    via Yelp

Questions, answered

Design and permitting come first and depend on the jurisdiction, then construction. Most single-family homes run 8–14 months from permit to occupancy; the homes on our portfolio took 7 to 10 months to build. We give you a phased schedule at contract and update it as permits and selections land.

Yes to both. We build on client-owned lots across our service areas, and the free advice visit is the right time to check feasibility: setbacks, slope, access, utilities at the street and whether the house you want fits the zoning. A sloped lot or tight access adds about 6% in our estimate tool and a steep, view or well-and-septic lot about 15%, so knowing that before you close matters.

One contract and one team: the plans, structural engineering, energy-code work and permit submittal are produced by the same company that pours the foundation and hangs the cabinets. You skip the handoff between a designer and a builder, the drawings are priced as they're drawn, and there is one number to call for the whole project.

Yes. We review them for buildability and code, add the structural engineering if it isn't stamped, and carry them through permitting and construction. Most clients keep design and build together for speed, but existing plans are a fine starting point.

The proposal prices the complete build from foundation to finish at the finish level you choose, with land, design and permit fees, utility connections and unusual soils listed separately. Changes you ask for after contract are written up as change orders with the cost and schedule effect before the work happens, so there are no surprises at the end.

The house as drawn — rooms, ceiling heights, windows and the light they bring, cabinets and the main finishes — so you can walk it before we frame it. Moving an island or a wall in the model costs nothing; moving it after rough-in does.

It depends on the structure, the lot and the program. Our Palatine project is the rebuild case: a 1950s bungalow replaced by a 4,254 sq ft three-level home on the same Seattle lot because the new program didn't fit the old frame. When the bones are good, an addition or whole-home remodel usually costs less — our estimate tool prices a full remodel at roughly a third to 40% of the local new-build rate per finished square foot.

Washington (Federal Way, Seattle, Bellevue and the Eastside, Snohomish County and Spokane), Idaho (Boise and Coeur d'Alene), Montana (Billings) and Arizona (Scottsdale and Tucson), with contractor's licenses in all four states. See the service-area list below for each city page.

Financing available — pre-qualify in minutes, no credit score impact.

Pre-qualify through Acorn Finance ($1,000–$100,000, 20+ lenders) or HFS Financial (up to $450,000, no home equity required).

Book your free professional advice visit

Free estimate. Free 3D design model. Free on-site advice from the builder who prices the job. No obligation.