Know exactly what to check before making an offer
Due Diligence Checklist
Generate a property-specific checklist based on city, property type, home age, and your specific concerns. Includes official research links for King County and Snohomish County.
TL;DR
Use this before making an offer on a specific property. It generates a targeted checklist based on location, property type, home age, and your specific concerns.
What this tool checks
- County and city — affects permit portals, parcel records, and local-specific concerns
- Property type — SFH, condo, or townhouse
- Home age — shapes the permit history focus and material-specific checks
- Specific concerns: slope, waterfront, mature trees, visible remodel, finished basement, older electrical or plumbing
Greater Seattle notes
- Sewer scope: standard practice before offering on a 20+ year home in Greater Seattle.
- Form 17: Washington State seller disclosure — review it before writing the offer.
- Permit history: check through city or county permit portals. Unpermitted work can affect financing and future resale.
- King County Assessor and Snohomish County SCOPI for assessed value, tax history, and ownership records.
- HOA resale certificate: required for condos and townhouses — request it early, not after mutual acceptance.
- Drainage, slope, and mature-tree concerns vary significantly across Seattle neighborhoods and hillside lots.
What this does not replace
- A physical inspection by a licensed inspector
- Title review
- Legal advice
- A strategy conversation with your agent
Answer a few questions about the property and we’ll generate a targeted checklist of what to research before making an offer.
Common questions
Do I need a sewer scope before offering in Seattle?▾
For homes over 20 years old in Greater Seattle, a sewer scope is common practice. Root intrusion is a leading cause of sewer issues, and scoping before the offer — or as part of the inspection — gives you information before you are under contract.
What should I check for an older Seattle home?▾
Roof age, electrical panel brand and condition, plumbing material (polybutylene if built 1978–1995), furnace and water heater age, crawl space condition, and permit history for any additions or remodels.
What changes for a condo or townhouse?▾
HOA documents become central: reserve study, meeting minutes, CC&Rs, and the resale certificate. The physical inspection focuses on in-unit systems and anything listed as owner-responsibility in the CC&Rs.
Where do I verify permit or parcel information?▾
King County: King County Assessor and the city’s permit portal. Snohomish County: SCOPI (Snohomish County Online Permitting and Information). Both counties have online parcel viewers with ownership and permit history.
Found a serious listing?
Send the listing and your checklist to Vera for a Listing X-Ray.
Vera Huang is a Washington licensed broker with WeLakeside. She built SeattleHomeWay for analytical Greater Seattle buyers who want to understand the numbers, risks, and tradeoffs before making an offer.