Small Multifamily Construction contractor —
Seattle & Puget Sound.
Small multifamily construction sits between single-family new construction and full mid-rise multifamily. We build 2–6 unit attached residential — townhomes, rowhouses, cottage clusters, small stacked flats — for owner-developers building under Washington's middle-housing law (HB 1110) and city implementation. Larger mid-rise wood-frame or concrete podium projects are outside our self-perform scope.
Small multifamily construction sits in a specific band: ground-up attached residential at 2–6 units per project, built under the International Residential Code where the configuration allows or the International Building Code where it does not. We build townhouses, rowhouses, cottage-cluster housing, and small stacked-flat projects for owner-developers building under Washington's HB 1110 middle-housing requirements and the local code amendments each city has adopted.
What this page is honest about: we do not build high-rise wood-frame mid-rise, concrete podium, or commercial multifamily. Those projects belong to specialized multifamily general contractors with the bonding, supervision, and permit-history those projects require, and we are happy to refer you to one when the scope is outside ours. Where we fit is small infill: a single parcel turning into a small cluster of homes, coordinated by one accountable contractor across feasibility, civil, permit, and vertical construction.
What we build
SCOPE- 01HB 1110 / middle-housing infill
- 02Townhouse + rowhouse construction
- 03Cottage cluster development
- 04Small stacked-flat configurations
- 05Civil + stormwater coordination
- 06Unit-lot subdivision or condo platting
Phased process
PROCESS- 01
Parcel + middle-housing feasibility
Verify zone, lot dimensions, and the unit count permitted under local middle-housing implementation (Seattle One Plan, Bellevue Middle Housing Code Update, etc.). Output: realistic unit count and product type.
- 02
Civil pre-screen
Stormwater detention, water service, side-sewer, fire-marshal access pre-screen at feasibility — frequently controls the developable envelope.
- 03
Product-type selection
Townhouse, rowhouse, cottage cluster, or small stacked-flat. Schematic site plan and preliminary unit plans.
- 04
Design + permit set
Coordinate architect, structural, civil, MEP, energy. Pre-check the set against the city's submittal requirements for the chosen product type.
- 05
Permit submittal + corrections
MUP / land-use, building, and civil permits filed in parallel where the AHJ allows. Coordinate corrections; respond inside the AHJ's expected response window.
- 06
Site prep + civil construction
Erosion control, demolition (if applicable), grading, side-sewer, water-service, stormwater detention, fire access.
- 07
Foundations + framing
Phased foundations and framing across the cluster; party-wall and fire-separation detailing per code path.
- 08
MEP + envelope + finishes
Standard sequence per unit, staged across the cluster to keep trades flowing.
- 09
Platting + final approvals
Unit-lot subdivision or condo platting coordinated with surveyor and the owner's attorney. Final inspections and CO per unit.
- 10
Phased turnover + warranty
Units turned over in sequence with marketing-ready handoff and per-unit warranty.
Spec sheet
SPEC- +Wood-framed construction (IRC or IBC per project configuration)
- +Party-wall and fire-separation assemblies per code path
- +WSEC-compliant envelope and mechanical (heat pumps standard)
- +Civil engineering and stormwater detention per local code + WA Ecology SWMM
- +Fire-access compliance per fire-marshal review
- +Unit-lot subdivision or condo platting coordination
- +Per-unit metering for water, sewer, gas (where applicable), and electric
Cost drivers
COST- Unit count and parcel dimensionsHigher unit counts spread fixed civil cost; narrow or constrained lots change product type and per-unit cost.
- Civil + stormwaterDetention sized to impervious area; sites with limited downstream capacity need tank-style detention, which adds real cost.
- Fire accessFire-marshal access standards sometimes require driveway widening, hammerheads, or sprinklers — all priced at civil pre-screen.
- Code path (IRC vs IBC)Projects that stay inside IRC limits run cheaper than projects crossing into IBC (fire separation, life safety, accessibility).
- Platting pathwayUnit-lot subdivision is generally simpler than condo platting; condo platting adds legal and ongoing HOA cost but offers more flexibility for shared elements.
Codes & permits
COMPLIANCE- HB 1110 (2023) — Washington middle housing
State law requiring cities planning under the Growth Management Act to allow more units on historically single-family lots, with counts depending on city size and transit proximity. Authoritative explainer at WA Commerce.
- International Residential Code / International Building Code
Project configuration determines the code path; we verify which applies at feasibility and design to the controlling code.
- Seattle SDCI — Townhouse, Rowhouse, Cottage Housing
Operational SDCI page governing development standards for these product types in Seattle.
- RCW 64.34 — Washington Condominium Act
Legal framework for condo platting when individual unit sale is part of the exit strategy.
- WA Ecology Stormwater Manual (Western Washington)
Technical standards governing detention, water-quality, and low-impact design on multi-unit sites.
Is small multifamily construction the right call?
- →You own a Puget Sound parcel that under middle-housing rules now supports 2–6 attached units
- →You are an owner-developer building a small townhouse, rowhouse, or cottage-cluster project for hold or sale
- →You want one accountable contractor across civil, permit, and vertical construction
- →Your project needs unit-lot subdivision or condo platting at the back end
Multifamily Construction questions
FAQQ.01
Do you build mid-rise or podium multifamily?
No. Our self-perform scope tops out at small attached residential — typically 2–6 units per project — built to IRC or low-occupancy IBC. Larger mid-rise wood-frame or concrete podium projects are outside our scope and we will refer you to a specialized multifamily GC.Q.02
Will HB 1110 let me build on my lot?
It depends on the city, the zone, the lot dimensions, and the city's local implementation under the Growth Management Act timeline. The WA Department of Commerce middle-housing page is the authoritative explainer, and the feasibility step gives a parcel-specific answer.Q.03
What's the difference between unit-lot subdivision and condo platting?
Unit-lot subdivision lets attached townhome units be sold fee-simple on individually-titled lots without condo overhead — simpler for buyers and lenders. Condo platting under RCW 64.34 offers more flexibility for shared elements but adds legal cost and ongoing HOA structure. We coordinate either; the choice is a legal/business decision for the owner and their attorney.Q.04
Do you handle the civil engineering and stormwater?
We coordinate with a licensed civil engineer from feasibility forward. Stormwater detention sized to impervious area is almost always a factor on multi-unit sites, and we want that answer before the architect spends a month drawing the wrong unit count.Q.05
Can you build at a fixed price?
Yes, after feasibility and civil pre-screen. The feasibility step exists so we can quote a number we will stand behind. Small multifamily contracts are more sensitive to civil-scope variability than single-family, which is why civil pre-screen happens at feasibility — not after.
SOURCE_LAYER / Official citations
Where these claims come from
Permit, code, and middle-housing statements on this page are sourced to the official publishers below. Click any title to read the primary document. Dates indicate when each URL was last hand-verified by an editor.
- Middle Housing in Washington — Department of Commerce Resource Hub
Authoritative state explainer for HB 1110 middle-housing unit counts, transit-proximity bonuses, and city implementation status.
Washington State Department of CommerceVerified 2026-06-08 - HB 1110 (2023) — Increasing middle housing in areas traditionally dedicated to single-family detached housing
Statutory text underlying every HB 1110 / middle-housing claim made on the page.
Washington State Legislature (Session Law)Verified 2026-06-08 - International Building Code (IBC) Adoption — Washington
Adoption of the IBC (with WA amendments) governs multifamily buildings of 3+ units when projects cross IRC limits.
Washington State Building Code CouncilVerified 2026-06-08 - Townhouse, Rowhouse, and Cottage Housing Development — SDCI
Development standards SDCI applies to townhouse, rowhouse, and cottage-cluster product types.
Seattle Department of Construction & InspectionsVerified 2026-06-08 - Washington Condominium Act — RCW 64.34
Legal framework for condo platting when individual unit sale is part of the exit strategy.
Washington State LegislatureVerified 2026-06-08 - Washington Stormwater Management Manual for Western Washington
Stormwater thresholds and design standards that typically govern multi-unit residential site work.
Washington Department of EcologyVerified 2026-06-08
This page is informational, not legal advice. Specific land-use, permit, or HB 1110 questions about a particular parcel should be directed to the appropriate AHJ or a Washington-licensed attorney.
Official resources & sources
- Source ↗WSEC 2021 Residential Energy CodeEnvelope, HVAC, hot-water and air-sealing requirements
- Source ↗WA HB 1110 — Middle housing lawStatewide middle-housing zoning preemption
- Source ↗WA HB 1337 — ADU statewide rulesTwo-ADU baseline, no owner occupancy, parking limits
- Source ↗WA Dept. of Commerce — ADU resources
- Source ↗WA L&I contractor license lookupVerify Golden State ADU Builders Inc · GOLDESA747LZ
- Source ↗Washington State Building Code CouncilStatewide adopted codes (IRC, IBC, WSEC)
Ready to scope your multifamily construction project?
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INTERNAL_LINKS / Deep Map