Washington Contractor Guide

Licensing in Washington

The average home improvement project in Washington runs about $46,000. That's above the roughly $35,540 national average project cost. That's the 8th-highest average project cost of the 50 states. Washington is one of 31 states that requires a statewide contractor license through Washington State Department of Labor & Industries (L&I) — always verify a contractor's license number before signing anything. The most common projects here are ADU construction, Deck addition and Roof replacement. Washington requires contractor registration through L&I. Verify at lni.wa.gov/licensing-permits/contractors.

Licensing body: Washington State Department of Labor & Industries (L&I)

How to Vet and Pay a Contractor Safely

Get at least three written bids for anything over a couple thousand dollars — a bid that's dramatically lower than the others is a red flag, not a deal. Never pay more than 10–30% upfront (many states cap deposits by law); the rest should follow a payment schedule tied to inspected milestones, with the final payment held until the work passes a final walkthrough. Confirm the contractor carries general liability and workers' comp insurance — ask for a certificate naming you, not just their word for it — and get every change order in writing before the work starts, not after. For structural, electrical, or plumbing work, confirm your contractor is pulling the required permits — unpermitted work can complicate a future sale and may not be covered by insurance if something goes wrong.