New Construction Contractors in Seattle

New construction contracting in Seattle represents one of the most regulated and structurally complex segments of the local building industry. Projects that involve constructing a building from the ground up — residential, commercial, or mixed-use — require coordination across licensing, permitting, zoning, and labor compliance frameworks that are distinct from renovation or remodel work. This page describes the professional categories, regulatory structure, and operational boundaries that define new construction contracting within Seattle's jurisdiction.

Definition and scope

New construction contracting refers to the professional activity of building structures on previously undeveloped or cleared sites, as distinguished from renovation, tenant improvement, or repair work performed on existing structures. In Seattle's regulatory framework, new construction projects trigger a distinct set of permit types, plan review processes, and inspection sequences administered by the Seattle Department of Construction and Inspections (SDCI).

The scope of new construction work spans single-family residential builds, multi-family residential structures, commercial buildings, mixed-use developments, and accessory dwelling units (ADUs) constructed as standalone structures. Each category is subject to different code requirements, fee schedules, and contractor qualification thresholds. The Seattle Residential Building Code governs one- and two-family dwellings, while the Seattle Building Code — based on the International Building Code (IBC) with local amendments — applies to commercial and multi-family construction.

Contractors operating in this sector are classified within Washington State's contractor licensing system. The Washington State Department of Labor and Industries (L&I) maintains the general contractor registration database and distinguishes between general contractors, specialty contractors, and limited electrical contractors. For a broader overview of how licensing categories function within Seattle, see Seattle Contractor Licensing Requirements.

This page's scope covers new construction contracting activity within Seattle city limits, governed by Seattle Municipal Code and Washington State statutes. It does not cover projects in unincorporated King County, Bellevue, Redmond, or other adjacent municipalities, where separate permitting authorities and code adoption schedules apply. Projects crossing jurisdictional lines require separate permit applications with each governing authority and are not covered by SDCI.

How it works

New construction projects in Seattle move through a defined regulatory sequence before, during, and after physical construction.

1. Pre-application and site review — The project owner or contractor engages SDCI to determine zoning compliance, lot coverage limits, height restrictions, and applicable design review requirements. Seattle's Mandatory Housing Affordability (MHA) program applies to projects within designated zones and imposes either affordable unit inclusion or in-lieu fee payments.
2. Plan submittal and permit issuance — Building permits for new construction are submitted through SDCI's electronic permit system. As of the fee schedule published by SDCI, permit fees for new construction are calculated on a valuation basis, with the 2023 base rate structure set at approximately $7.25 per $1,000 of valuation for the first $1 million (SDCI Fee Schedule). Plan review for new commercial structures typically requires review by structural, mechanical, electrical, and fire code disciplines.
3. Contractor registration verification — General contractors must hold a current Washington State contractor registration through L&I, carry a minimum $12,000 contractor bond (L&I Contractor Bonding Requirements), and maintain general liability insurance. Specialty subcontractors — including Seattle Electrical Contractors, Seattle Plumbing Contractors, and Seattle HVAC Contractors — must hold their respective trade licenses issued by L&I.
4. Inspections — SDCI schedules mandatory inspections at foundation, framing, mechanical rough-in, insulation, and final stages. The general contractor coordinates inspection scheduling and is responsible for site readiness.
5. Certificate of Occupancy — Final approval results in a Certificate of Occupancy (CO), which is required before any new structure is legally occupied.

The Seattle Contractor Permit Process and Seattle Building Codes for Contractors pages provide additional regulatory detail for each stage.

Common scenarios

New construction contracting in Seattle clusters around four recurring project types:

Single-family residential new construction — Involves a general contractor overseeing site preparation, foundation, framing, mechanical systems, and finish trades. Seattle's sloped topography and expansive soil conditions make Seattle Foundation and Structural Contractors critical subcontractors on a majority of residential new builds.

Accessory Dwelling Units (ADUs) — detached — Seattle's 2019 ADU legislation, codified in Seattle Municipal Code Title 23, removed limits on ADU construction on single-family lots. Detached ADUs function as new construction projects and require full building permits, distinct from attached ADU alterations.

Multi-family residential construction — Projects with 5 or more units fall under the Seattle Building Code and trigger design review, energy code compliance under the Washington State Energy Code (WSEC), and often MHA obligations.

Commercial ground-up construction — Involves general contractors holding sufficient bonding and insurance for commercial-scale work, coordination with Seattle Public Works Contractors for utility connections, and compliance with Seattle's Green Building Program for projects above 50,000 square feet.

Decision boundaries

Distinguishing new construction from adjacent contractor categories matters for permit selection, contractor qualification requirements, and contract structuring.

New construction vs. renovation — A renovation or remodel involves modifying an existing permitted structure. New construction involves establishing a new structure on a prepared site, including foundation work, utility service connections, and a full envelope. The permit type (new construction permit vs. alteration permit) determines which code edition applies and which inspection sequence is required. Seattle Home Renovation Contractors operate under a different permitting pathway than new construction specialists.

General contractor vs. construction manager — On larger new construction projects, an owner may engage a construction manager (CM) who does not self-perform work but coordinates subcontractors. Washington State does not separately license construction managers, but CMs who hold or award subcontracts are required to maintain contractor registration through L&I.

Licensed specialty trades on new construction — General contractors on new construction projects cannot self-perform electrical, plumbing, or mechanical work without holding the respective trade license. Subcontractor relationships on new construction projects are governed by written subcontracts; Seattle Subcontractor Relationships outlines how those arrangements are structured and what documentation L&I and SDCI require.

Sustainable construction requirements — Seattle's Green Building Program mandates LEED certification or equivalent for new commercial construction above defined thresholds. Seattle Sustainable and Green Contractors describes the contractor qualifications associated with those compliance obligations.

For a complete overview of contractor service categories active in Seattle and how new construction fits within the broader local market, the Seattle Contractor Authority index provides the full sector map.

Project owners evaluating cost structures for new construction should consult Seattle Contractor Cost Estimates, while those assessing risk factors in contractor selection can reference Seattle Contractor Red Flags.

References

• Seattle Department of Construction and Inspections (SDCI)
• Washington State Department of Labor and Industries – Contractor Licensing
• L&I Contractor Bond and Insurance Requirements
• SDCI Permit Fees
• Seattle Residential Building Code
• Seattle Green Building Program
• Washington State Energy Code – Washington State Department of Commerce
• Seattle Municipal Code Title 23 – Land Use Code
• Seattle Office of Planning and Community Development – Mandatory Housing Affordability