What Washington sellers must disclose under RCW 64.06, how NWMLS Form 17 works, the risks of non-disclosure, and how buyers should use the form during due diligence.
Written by Isaac Ortiz · Real Estate Broker · Compass | NWMLS #146754
Washington's Seller Disclosure Act (RCW 64.06) requires sellers of residential property to complete a Seller Disclosure Statement before a buyer can be bound by a purchase and sale agreement. NWMLS Form 17 is the standard disclosure form used in Western Washington for most 1–4 unit residential transactions. The disclosure standard is actual knowledge — you're required to share what you know, not to investigate or hire inspectors to discover facts you don't have. 'I don't know' is a legally acceptable answer when you genuinely don't know. Guessing incorrectly to make the property look better creates exposure that survives closing. The buyer receives a three-business-day window to review the form after delivery and can rescind the purchase and sale agreement for any reason during that period, with full return of earnest money.
Form 17 walks through the home systematically. Structural questions cover the roof, foundation, walls, and any known settling, water intrusion, or prior structural repairs. Systems questions cover electrical (age, known issues, any unpermitted panel work), plumbing (water supply type, sewage — septic or municipal, known leaks or staining), heating and cooling (fuel type, age, known failures), and appliances included in the sale. Environmental questions carry particular weight in the PNW: radon, lead paint (pre-1978 homes also require a federal Lead-Based Paint Addendum), asbestos (present in floor tiles, pipe insulation, and ceiling texture in many pre-1978 homes), urea formaldehyde insulation, and any known moisture intrusion or mold conditions. Properties on or near water must disclose flood zone status. Sellers who have made improvements — permitted or not — are asked about them as well.
Beyond physical condition, Form 17 asks about legal conditions affecting the property. Easements — utility easements, access easements, neighbor rights-of-way — must be disclosed if known. Encroachments by or onto neighboring properties, boundary disputes, and pending special assessments from the city or county (road improvement districts, local improvement districts) are all required disclosures. For properties in a homeowners association or condominium, separate HOA disclosure requirements apply: sellers must disclose dues, pending litigation, and pending special assessments, and buyers have a right to review CC&Rs, reserve fund statements, and meeting minutes before the three-day window closes. Unpermitted additions or alterations are a common source of post-closing disputes. Sellers who know about unpermitted work and don't disclose it carry liability that can survive the sale — if a buyer later discovers an unpermitted addition, the non-disclosure claim is available.
Washington's Seller Disclosure Act gives buyers a right to rescind within three business days of receiving Form 17. This window is statutory — the buyer can walk away and recover earnest money regardless of what the form says, simply because the three-day review right exists. Non-disclosure of known material defects is a different and more serious matter. If a seller knows about a material defect — prior roof leak, foundation movement, unpermitted addition — and omits it, the buyer can bring a post-closing misrepresentation or fraud claim. Washington courts have found sellers liable for non-disclosure years after closing when the concealment was intentional, because intentional fraud claims can survive the merger doctrine that otherwise limits post-closing claims. The safest posture is thorough disclosure. If a prior problem was repaired — a roof leak that was remediated, a foundation crack that was stabilized — disclose both the prior condition and the repair. Discovering evidence of a concealed prior problem is exactly the scenario that generates litigation.
Form 17 is not a home inspection report — it is the seller's knowledge, which may be incomplete, conservative, or in some cases inaccurate. Read it as a map to your inspection priorities. Any 'yes' answer in the structural, water intrusion, or environmental sections should prompt a direct conversation with your inspector about that area before you remove the inspection contingency. 'I don't know' answers deserve the same attention — on estate sales or investor flips where the seller has never occupied the property, many questions will be 'I don't know,' which means your inspector should probe those areas more thoroughly. Pay particular attention to moisture and mold disclosures, septic status, and any prior flooding in PNW properties. The Puget Sound climate's wet winters make moisture intrusion the most common and costly condition that buyers discover after closing in this region. If you identify a Form 17 answer that appears inconsistent with what your inspector finds, Washington law allows you to use that discrepancy as evidence in a post-closing misrepresentation claim.
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