Seattle Commercial General Contractor & Design-Build
Terrapin Construction Group is Seattle's integrated design-build general contractor — delivering commercial construction across Puget Sound, the Pacific Northwest, and 38 states with in-house architecture, engineering, preconstruction, and self-performing specialty trades.
Seattle Construction Cost Estimator
Describe your Puget Sound project and get a preliminary cost estimate powered by TCG.ai — free, instant, and calibrated to Washington State market pricing.
Tell Us About Your Seattle Project
Include details about building type, size, location in Puget Sound, special requirements, and timeline. Our AI applies Seattle-specific cost indices, prevailing wage, and seismic requirements automatically.
Analyzing Your Seattle Project
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Your Seattle Construction Cost Estimate
Seattle's Integrated Design-Build General Contractor
Terrapin Construction Group serves the Puget Sound region from 1700 Westlake Ave N, #200, Seattle, WA 98109 as an integrated commercial general contractor operating across 38 states. We bring national-scale resources and deep construction expertise to every project in the Pacific Northwest — from South Lake Union and Capitol Hill to Ballard, Georgetown, SoDo, Bellevue, Redmond, Kirkland, Tacoma, Everett, and the entire I-5/I-405 corridor.
What makes TCG different from other Seattle general contractors is our fully integrated model. We don't just manage subcontractors — we provide in-house architectural design, structural engineering, MEP engineering, preconstruction, and construction management under one design-build contract. We self-perform critical scopes including IMP installation, PEMB erection, commercial roofing, commercial flooring, and equipment procurement.
Our team understands local permitting through the City of Seattle Department of Construction and Inspections (SDCI), King County, Pierce County, Snohomish County, and the Eastside municipalities. We know the Puget Sound subcontractor market — which has a strong union and prevailing wage presence and is heavily influenced by tech sector construction demand from Amazon, Microsoft, Google, and Meta — and the specific challenges of building in Washington, from Cascadia Subduction Zone seismic requirements (Seismic Design Category D) to the Pacific Northwest's persistent rain and moisture management demands, Seattle's notoriously long permitting timelines (8–20 weeks), and the Eastern Washington data center corridor (Quincy/Moses Lake) powered by cheap Columbia River hydroelectric.
What We Deliver in Seattle
Design-Build
Single-source design-build — architecture, engineering, and construction under one contract. 15–30% faster. One point of accountability.
General Contracting
Competitive general contracting from client-provided plans. Subcontractor procurement, site supervision, schedule management across Puget Sound.
Preconstruction
Preconstruction budgeting, scheduling, constructability reviews, and value engineering. Seattle-specific cost data, prevailing wage intelligence, and seismic design planning.
Architecture & Engineering
In-house architectural design, structural engineering, and MEP engineering — designed for Washington's seismic and moisture requirements.
Construction Management
Construction management (CM-at-Risk and CM Agency) and owner's representative services for Seattle owners.
Self-Performing Specialties
IMP installation, PEMB erection, commercial roofing, commercial flooring, and equipment procurement.
TCG Construction Services in Seattle
Every service TCG offers is available in the Puget Sound region and throughout Washington State. Our integrated model means these capabilities work together under one contract.
IMP Installation, Commercial Roofing, PEMB & Flooring in Seattle
TCG self-performs several critical construction scopes in the Seattle market that most general contractors subcontract out — giving us direct control over cost, quality, and schedule on the trades that matter most.
Insulated Metal Panel (IMP) Installation — TCG has installed over 1,000,000 SF of IMP across 38 states, including projects throughout Washington and the Pacific Northwest. The PNW's persistent moisture and rain make IMP's vapor-tight, continuous insulation envelope especially valuable — critical for cold storage, data centers, manufacturing, and cleanroom/lab environments. Use our IMP cost estimator for Seattle pricing.
Commercial Roofing — Seattle's persistent rain (152 rainy days per year), marine climate, and moss/algae growth demand superior waterproofing and drainage design on every commercial roof. TCG provides commercial roofing including TPO, EPDM, modified bitumen, standing seam metal, and built-up roofing across Puget Sound. Proper drainage, tapered insulation, and moisture-resistant details are non-negotiable in the Pacific Northwest climate.
Pre-Engineered Metal Buildings (PEMB) — PEMBs are the most cost-effective structural system for Puget Sound warehouses, distribution centers, manufacturing facilities, and self storage. TCG self-performs PEMB erection and coordinates directly with our IMP installation crews. PEMBs in Washington require enhanced seismic connections (SDC D) and corrosion protection for the marine climate. The I-5 corridor and Port of Seattle/Tacoma drive strong demand.
Commercial Flooring — TCG self-performs commercial flooring installation throughout Puget Sound, including polished concrete, epoxy coatings, resinous flooring, VCT, LVT, carpet tile, and specialty flooring systems. Seattle's marine climate makes moisture vapor emission testing and substrate preparation especially critical. Flooring is essential for the region's booming biotech market (ESD and cleanroom), warehouses (forklift-rated coatings), restaurants (slip-resistant), and healthcare (infection control). Self-performing eliminates a common schedule bottleneck.
What We Build in Seattle & Washington
TCG builds across every commercial sector in the Puget Sound region and throughout Washington State. Each expertise page includes a sector-specific AI cost estimator.
How Much Does Commercial Construction Cost in Seattle?
Seattle carries a regional cost multiplier of approximately 1.12–1.28x versus the national average, driven by prevailing wage requirements, strong union presence, seismic design costs (SDC D adds 5–15% to structural), tech-sector labor competition, and Seattle's notoriously long permitting timelines. Seattle is one of the most expensive construction markets outside of New York and San Francisco, comparable to Boston (1.15–1.30x) and Washington DC (1.15–1.30x). No state income tax partially offsets the high construction costs.
Seattle construction costs by type: Warehouses $100–$200/SF. Offices $180–$430/SF. Restaurants $230–$480/SF. Medical $240–$580/SF. Veterinary clinics $240–$580/SF. Self storage $32–$140/NRSF. Tenant improvements $40–$580/SF depending on use. Data centers $360–$1,500/SF. Manufacturing $120–$580/SF. Cold storage $150–$360/SF.
Key Seattle-specific cost factors include Cascadia Subduction Zone seismic requirements (SDC D, moment frames, special detailing adding 5–15% to structural), prevailing wage and union labor, persistent moisture (advanced waterproofing and vapor management), tech-sector labor competition (Amazon, Microsoft, Google absorb significant trade capacity), and City of Seattle SDCI permitting (8–20 weeks — among the longest in the country). Use our AI estimator above, or schedule a meeting with our preconstruction team.
Seattle Commercial Construction FAQ
Common questions about building in the Puget Sound region. Visit our full FAQ page for 70+ questions.
Seattle costs range from $100–$200/SF for warehouses to $360–$1,500/SF for data centers. The regional multiplier is 1.12–1.28x national average, driven by prevailing wage, seismic design, and tech-sector labor competition. Use our AI estimator or general estimator.
Yes — TCG serves Puget Sound from 1700 Westlake Ave N, #200, Seattle, WA 98109. Our headquarters is in Denver, with additional offices in Houston, Albany, Charlotte, Atlanta, Columbus, Phoenix, Chicago, Washington DC, Nashville, Tampa, Indianapolis, Las Vegas, Salt Lake City, and Minneapolis.
All commercial sectors: warehouses and cold storage, restaurants and hotels, medical offices, manufacturing, labs, veterinary clinics, self storage, data centers, tenant improvements, and adaptive reuse.
Washington State requires prevailing wages on all public works projects. Seattle also has its own prevailing wage and labor standards. The Puget Sound region has a strong union labor presence, particularly for commercial and industrial construction. Washington's prevailing wage rates are among the highest in the country. TCG has extensive experience managing prevailing wage projects nationwide.
Seattle sits in Seismic Design Category D due to the Cascadia Subduction Zone and shallow crustal faults. The Washington State Building Code requires enhanced seismic design including moment frames, braced frames, and special detailing that add 5–15% to structural costs. TCG's structural engineers design for Washington's seismic requirements on every project.
Absolutely — Seattle is a global tech capital home to Amazon, Microsoft, Google, Meta, and hundreds of tech companies. The metro drives massive demand for office tenant improvements, labs, and manufacturing. Eastern Washington around Quincy and Moses Lake is one of the largest data center markets in the world, powered by cheap Columbia River hydroelectric. TCG provides design-build data center construction with critical power, precision cooling, and IMP envelope systems.
Design-build combines design and construction under one contract — 15–30% faster, single-point accountability, fewer change orders. In Seattle's high-cost market with 8–20 week permitting, design-build's schedule compression saves significant prevailing wage labor costs.
TI: 2–6 months. Restaurant: 4–8 months. Office: 8–16 months. Warehouse: 6–12 months. Medical: 10–20 months. Manufacturing: 12–24 months. City of Seattle SDCI permitting adds 8–20 weeks — among the longest in the country. Rain can slow exterior work but rarely stops it. Design-build compresses timelines by 15–30%.
Yes — TCG self-performs IMP installation with over 1,000,000 SF installed across 38 states. The PNW's persistent moisture makes IMP's vapor-tight envelope especially valuable. Use our IMP estimator for Seattle pricing.
Yes — TCG provides commercial roofing services across Puget Sound including TPO, EPDM, modified bitumen, standing seam metal, and built-up roofing. Seattle's persistent rain (152 rainy days/year), marine climate, and moss growth demand superior waterproofing and drainage on every roof.
Yes — TCG self-performs PEMB erection throughout Puget Sound. PEMBs in Washington require enhanced seismic connections (SDC D) and corrosion protection for the marine climate. The I-5 corridor and Port of Seattle/Tacoma drive strong demand for PEMB warehouse construction.
Yes — TCG self-performs commercial flooring installation throughout Puget Sound including polished concrete, epoxy coatings, resinous flooring, VCT, LVT, carpet tile, and specialty systems. Seattle's marine climate makes moisture vapor testing and substrate prep especially critical.
No. TCG provides in-house architectural design, structural engineering, and MEP engineering. We also bid from existing plans as a general contractor. Try our free Seattle AI estimator to start.
All of Puget Sound — Downtown Seattle, South Lake Union, Capitol Hill, Ballard, Fremont, Queen Anne, Georgetown, SoDo, and every Seattle neighborhood. Plus Bellevue, Redmond, Kirkland, Bothell, Lynnwood, Everett, Tacoma, Kent, Renton, Auburn, Federal Way, Issaquah, and throughout Washington including Spokane, Vancouver, Bellingham, Olympia, and the Tri-Cities.
Let's Build in Seattle
From South Lake Union to Tacoma, from restaurants to data centers — TCG is Puget Sound's integrated design-build general contractor. Let's talk about your project.
Schedule a Seattle Consultation