Washington Seller Disclosure Requirements: What Home Sellers Must Reveal

Washington State requires sellers of residential property to complete one of the most detailed disclosure forms in the country. Known officially as Form 17, the Seller Disclosure Statement runs multiple pages and asks pointed questions about everything from roof leaks and foundation cracks to environmental contamination and neighborhood nuisances. For buyers, this form is a gold mine of information — if the seller fills it out honestly. For sellers, it’s a legal obligation that can come back to haunt them if they conceal known defects. The form also gives Washington buyers a unique right: the ability to rescind the purchase agreement within a set period after receiving the disclosure, no questions asked.

What Form 17 Requires

The Seller Disclosure Statement is governed by RCW 64.06, Washington’s real property disclosure act. Every seller of residential property (one to four units) must provide a completed Form 17 to the buyer unless an exemption applies. The form covers the following categories, each with detailed yes/no/don’t-know questions:

Title and ownership: Encumbrances, easements, boundary disputes, liens, shared driveways, party walls, and encroachments. Sellers must disclose any known title defects or pending legal actions affecting the property.

Water and sewer: Whether the property connects to a public sewer or uses a septic system, the age and condition of the septic system if applicable, any history of sewer backups or failures, and well water details if the property uses a private well. Septic disclosures are particularly important in rural King County, Pierce County, and throughout eastern Washington where many homes rely on on-site systems.

Structure and systems: The condition of the roof, foundation, walls, floors, insulation, heating and cooling systems, plumbing, electrical, and appliances that convey with the sale. Sellers must note any known defects, past repairs, and current problems. If the roof was patched three years ago because of a leak, that goes on the form.

Environmental hazards: Lead-based paint (mandatory for homes built before 1978 under federal law), asbestos, radon, underground storage tanks, contaminated soil or groundwater, flooding history, drainage problems, and proximity to known contamination sites. Washington’s industrial history — timber processing, mining, military installations — means environmental issues are more common than many buyers expect.

Neighborhood and land use: Noise from highways, airports, or railroads; odors from agricultural operations or industrial facilities; pending zoning changes; planned development nearby; and whether the property is in a critical area (wetland, steep slope, flood zone, or landslide hazard area). This section is especially relevant in the Puget Sound region, where urban growth boundaries and critical area ordinances significantly affect what you can do with a property.

How the Disclosure Process Works

The typical timeline for Form 17 disclosure in a Washington real estate transaction follows this pattern:

The seller completes Form 17 before or shortly after listing the property. Many listing agents encourage sellers to fill it out upfront so it can be provided to interested buyers immediately, reducing delays during the offer and negotiation phase.

Once an offer is accepted and a purchase and sale agreement (PSA) is signed, the seller must deliver the completed disclosure to the buyer. If the seller has already provided it, delivery is satisfied. If not, the seller must provide it within five business days of mutual acceptance (or whatever the contract specifies).

After receiving the disclosure, the buyer has three business days to review it. During this period, the buyer can rescind the purchase agreement for any reason related to the disclosure — or even for no stated reason at all. This right of rescission is one of the strongest buyer protections in Washington real estate law. If the buyer doesn’t like what they see on Form 17, they can walk away and get their earnest money back.

The rescission right is separate from the inspection contingency. Even if you waive the inspection contingency (common in competitive Seattle-area markets), you still have the right to rescind based on the seller’s disclosure. Smart buyers use both protections strategically when purchasing in Washington.

What Sellers Must Disclose (and What They Can Skip)

Sellers are obligated to disclose what they actually know. The form uses a three-option format for most questions: Yes, No, or Don’t Know. A seller who genuinely doesn’t know whether there’s asbestos in the attic can check “Don’t Know” without liability. However, a seller who knows about asbestos but checks “Don’t Know” commits fraud.

The “Don’t Know” option is where disputes most often arise. Sellers sometimes use it as a shield, claiming ignorance of problems they should reasonably have known about. Washington courts have held that sellers can be liable for failing to disclose problems that were obvious or should have been known to someone living in the property — the legal standard isn’t perfect knowledge, it’s good faith disclosure.

Mold History and Water Damage

Washington’s wet climate — particularly west of the Cascades — makes water intrusion and mold significant concerns. The Puget Sound region receives 35 to 50 inches of rain annually, and older homes without modern vapor barriers, adequate drainage, or proper ventilation are prone to moisture problems. Form 17 asks specifically about:

Past water damage: Any history of leaks, flooding, standing water in crawl spaces, or water intrusion through walls, windows, or foundations. Sellers must disclose even if the problem was repaired.

Mold or mildew: Any known presence of mold, past mold remediation, or conditions that are likely to produce mold (persistent moisture, poor ventilation). Washington doesn’t have specific mold disclosure laws beyond Form 17, but the general disclosure obligation covers it.

Drainage issues: Whether the lot drains properly, whether standing water collects during rain events, and whether any drainage improvements have been made. In hilly Seattle neighborhoods and throughout the landslide-prone areas of Puget Sound, drainage is a major property value factor.

For buyers, a seller’s disclosure of past water damage or mold remediation isn’t necessarily a dealbreaker — it’s actually valuable information. A problem that was properly repaired and disclosed is far better than an undisclosed problem discovered after closing. Focus your home inspection on areas where the seller disclosed prior issues, and ask for documentation of any professional remediation work.

Septic Systems and Sewer Connections

Roughly one-third of Washington homes use on-site septic systems rather than public sewer connections. In rural areas, that percentage climbs much higher. Form 17 asks detailed questions about septic systems, including the type of system, its age, when it was last inspected and pumped, whether it has ever failed, and whether any repairs or replacements have been done.

Washington counties have their own regulations regarding septic system inspections at the time of property transfer. In King County, for example, the seller must provide an operating permit for the septic system, and many lenders require a septic inspection as a condition of financing. A failing septic system can cost $15,000 to $40,000 to replace — a cost that dramatically changes the economics of a transaction.

Buyers should treat the septic disclosure section with particular care. Ask follow-up questions if the seller checks “Don’t Know” on septic-related items. Request pump and inspection records. If records don’t exist, budget for a professional septic inspection as part of your due diligence. This is one area where the cost of an inspection ($300-$500) is trivially small compared to the potential repair bill.

Lead Paint Disclosure

Federal law requires sellers of homes built before 1978 to provide a separate lead-based paint disclosure in addition to Washington’s Form 17. The seller must disclose any known lead paint, provide any available lead testing reports, and give the buyer a 10-day window (unless waived) to conduct a lead inspection.

In Washington, this affects a large number of properties. Seattle alone has tens of thousands of homes built before 1978, many in popular neighborhoods like Capitol Hill, Ballard, Wallingford, and the Central District. The lead disclosure is not optional — it’s a federal requirement with penalties for non-compliance, separate from and in addition to Form 17.

The Buyer’s Right to Rescind

Washington’s three-business-day rescission period after receiving the seller disclosure is one of the strongest buyer protections in any state. During this window, you can cancel the purchase agreement and recover your earnest money deposit — no explanation required. The right exists specifically to give buyers time to evaluate the disclosure without pressure.

In practice, the rescission right works as a safety valve. If the seller discloses a serious defect you weren’t aware of — a history of flooding, a failing septic system, contaminated soil — you can exit the deal cleanly. This is especially important in Washington’s competitive markets, where buyers sometimes waive inspection contingencies to make their offers more attractive. The disclosure rescission right remains intact even if you waive the inspection.

Sellers and their agents sometimes try to deliver the disclosure before mutual acceptance to “start the clock” early and reduce the buyer’s post-acceptance rescission window. This is a legitimate strategy, and if you review the disclosure before making your offer, you’ve already had time to evaluate it. Discuss timing strategy with your buyer’s agent to maximize your protection.

Exemptions from Form 17

Not every sale requires a Form 17 disclosure. Exempt transactions include:

Foreclosure sales: Banks selling foreclosed properties are not required to provide Form 17, and they typically disclose nothing about the property’s condition. Buyers purchasing foreclosures should budget for thorough inspections.

Court-ordered sales: Probate sales, tax lien sales, and other court-ordered transfers are generally exempt from disclosure requirements.

New construction: Builders of new homes are exempt from Form 17, though they have separate obligations under Washington’s construction defect statutes and implied warranty of habitability.

Transfers between family members: Gifts and transfers between spouses, parents, and children in certain circumstances.

For first-time homebuyers, understanding these exemptions is important. If you’re considering a foreclosure or estate sale without a disclosure, you’re taking on more risk. Invest in a thorough home inspection, sewer scope, septic inspection (if applicable), and potentially a Phase I environmental assessment for properties near former industrial or commercial sites.

Impact on Homebuyers and Sellers

For buyers, the seller disclosure is your first and often best source of property information. Read every line of Form 17 carefully. Pay attention to “Yes” answers, but also scrutinize “Don’t Know” responses — an excessive number of “Don’t Know” answers on a property the seller has lived in for 20 years suggests the seller may not be forthcoming.

Cross-reference the disclosure with your home inspection results. If the inspector finds a problem the seller claimed not to know about — water stains in the attic on a home where the seller checked “Don’t Know” for roof leaks — that discrepancy is worth investigating. It could be innocent, or it could indicate concealment.

For sellers, honesty on Form 17 is both a legal requirement and practical self-protection. Washington courts have awarded significant damages to buyers who discovered concealed defects, including the cost of repairs, diminished value, and in some cases attorney fees. The statute of limitations for disclosure-related claims is generally three years from closing or discovery of the defect, whichever is later. Disclosing a known problem upfront — even one that might reduce your sale price — is almost always cheaper than defending a lawsuit after the fact.

If you’re planning to sell a Washington home, fill out Form 17 thoroughly and accurately with your listing agent. If you’ve had work done on the property — roof replacement, foundation repair, mold remediation, septic pump-outs — gather documentation and attach it to the disclosure. Buyers are reassured by documentation showing that problems were professionally addressed.

For a full understanding of transaction costs on both sides of the deal, review our guide to Washington closing costs, which covers real estate excise tax, title insurance, and other expenses that accompany the disclosure and inspection process.

Frequently Asked Questions

What is Form 17 in Washington real estate?

Form 17 is the Seller Disclosure Statement required by Washington law (RCW 64.06) for most residential property sales. The seller completes it with detailed information about the property’s condition, including the roof, foundation, plumbing, electrical, septic/sewer, environmental hazards, water damage, mold, boundary issues, and neighborhood factors. The form uses a yes/no/don’t-know format for most questions and must be delivered to the buyer before or shortly after mutual acceptance of a purchase agreement.

Can a buyer cancel a deal based on the seller disclosure?

Yes. Washington law gives buyers three business days after receiving the seller disclosure to rescind the purchase agreement for any reason related to the disclosure. During this period, the buyer can cancel and recover their earnest money deposit without penalty. This right exists even if the buyer waived the home inspection contingency. If the seller amends the disclosure after initial delivery, a new three-day rescission period begins for the amended items.

What happens if a seller lies on Form 17?

A seller who knowingly conceals a material defect or provides false information on Form 17 faces legal liability. The buyer can sue for damages including repair costs, diminished property value, and potentially attorney fees. Washington courts take disclosure fraud seriously, and the statute of limitations runs three years from the date the buyer discovers (or should have discovered) the concealed defect. The seller’s real estate agent may also face liability if they were aware of the misrepresentation.

Does the seller have to disclose mold in Washington?

Yes. Form 17 asks about any known presence of mold or mildew, past mold remediation, and conditions likely to produce mold (moisture problems, poor ventilation). If the seller knows about mold or has had professional remediation done, they must disclose it. Given western Washington’s wet climate, mold disclosures are common and not necessarily alarming — what matters is whether the underlying moisture issue was properly addressed and whether the remediation was done by a qualified professional.

Are sellers required to disclose a death in the property?

Washington law does not specifically require sellers to disclose that someone died in the property. However, if the death created a condition that affects the property’s physical state — for example, if a long-undiscovered death caused damage to floors or materials — that physical damage must be disclosed. Some sellers voluntarily disclose deaths out of an abundance of caution, but there’s no legal requirement to do so for natural deaths or other non-property-damaging events.

What if the seller checks “Don’t Know” for everything?

A Form 17 with an excessive number of “Don’t Know” answers is a warning sign, especially if the seller has lived in the home for years. While sellers are permitted to answer “Don’t Know” when they genuinely lack knowledge, courts have held that sellers cannot use “Don’t Know” to avoid disclosing information they reasonably should have known. If you receive a disclosure that looks evasive, invest in a thorough home inspection and consider asking the seller’s agent for clarification on specific items.

Do I need a home inspection if I have the seller disclosure?

Absolutely. The seller disclosure is based on the seller’s knowledge — it’s not a professional assessment of the property’s condition. Many defects are hidden behind walls, under floors, or in areas the seller may never have examined. A professional home inspector checks the structure, systems, and components systematically and may find issues the seller genuinely didn’t know about. Think of Form 17 as a starting point for investigation, not a substitute for inspection.

Does Form 17 apply to condominiums?

Yes, with additional requirements. Condo sellers must complete Form 17 for their individual unit and also provide the buyer with the condominium resale certificate, which contains information about the homeowners’ association — financial statements, meeting minutes, rules and restrictions, pending litigation, special assessments, and reserve fund status. The resale certificate is separate from Form 17 and gives the buyer critical information about the association’s financial health and governance that the individual seller may not know.