Home Inspections in King County: Sewer Scopes, Oil Tanks & PNW Red Flags

The core inspection — and what it costs here

Washington inspectors are state-licensed. A general inspection of a King County single-family home runs roughly $450–$800 and covers roof, structure, exterior, electrical, plumbing, heating, insulation, and attic/crawlspace — 3–4 hours you should attend in person. The report will list dozens of items; what matters is separating the $50 fixes from the $30,000 ones.

The sewer scope: the most important $300 you'll spend

In Seattle and older suburbs, the 'side sewer' — the pipe from the house to the city main — belongs to the homeowner, and many are 60–100-year-old concrete or clay, invaded by roots or sagging ('bellied'). Replacement commonly costs $10,000–$30,000+, more if it runs under the street. A camera scope costs around $250–$400. On any home older than ~1990, treat it as mandatory, ideally before your offer on review-date listings.

PNW-specific red flags

None of these automatically kills a deal — Seattle buyers purchase 100-year-old homes every day. The goal is pricing the known work into your offer instead of discovering it after closing.

• Buried heating-oil tanks: pre-1970s homes often had them. Ask for a decommissioning certificate; an undiscovered leaking tank is an environmental cleanup problem.
• Moisture everywhere: crawlspace standing water, roof moss, failing gutters, negative grading. Water findings are the ones that grow if ignored.
• Knob-and-tube and 60-amp panels in pre-1950s Seattle craftsman homes — insurers and lenders may require remediation.
• Earthquake vulnerability: pre-1980 homes may lack foundation bolting; a seismic retrofit runs roughly $5,000–$15,000 and can cut insurance costs.
• Asbestos (ducting, popcorn ceilings) and lead paint in older stock — priced-in if managed, expensive if disturbed by your remodel plans.

Negotiating what you find

Under the standard inspection contingency you can approve, walk away, or ask for repairs/credits — and the seller can refuse. Prioritize: ask for money or fixes on safety and big-ticket systems (sewer, roof, electrical, structure), not cosmetic lists. Sellers respond better to one clean request backed by contractor bids than to a 40-item nickel-and-dime list.

In multiple-offer situations where you pre-inspected, your leverage moves earlier: the findings shape your offer price rather than a post-acceptance negotiation.