Home inspection checklist: 30 items for Washington State buyers, first-time homebuyers, and anyone buying an older house

How the home inspection works in Washington

The inspection contingency lives in Form 35. Once the seller accepts your offer, you have the stated number of days, 10 by default, to inspect the home and give the seller one of three notices. You approve, you ask for repairs or a credit, or you terminate and take back your earnest money. If the home inspector recommends a specialist, Form 35 lets you request additional time for that follow-up inspection. You have to ask before the first period ends, and the number of extra days is written into the form.

Repair requests go on Form 35R. The seller can agree, refuse, or counter, and the response windows for both sides are short, measured in days and set in the form. If you let the deadline pass without a notice, the contingency is waived. The timeline is short on purpose, so book the inspector the day the offer is accepted, not the day after.

Washington requires home inspectors to be licensed. The license takes 120 hours of classroom training, 40 hours of field training, and a state exam. Ask for the license number and check it on the Department of Licensing site. A good home inspector in the Seattle area is booked a week out in a busy spring, which is another reason to call early.

Exterior and site: items 1 to 6

1. Grading and drainage. The ground should slope away from the foundation on every side. In Western Washington, where it rains 150 days a year, flat or negative grading is the single most common cause of a wet crawl space. Look for soil that touches siding, and downspouts that end at the foundation instead of in a drain or a splash block.
2. Siding and trim. Check for soft or spongy wood at the bottom of trim boards and where siding meets the ground. Peeling paint on a south or west wall is cosmetic. Peeling paint with soft wood behind it is rot.
3. Windows and doors. Open every window. Look for fogging between the panes, which means the seal has failed, and for rot at the sill. Count the single-pane windows; they will show up on your heating bill.
4. Decks, porches, and stairs. The inspector will check the ledger board where the deck meets the house, the posts and footings, and the railings. Decks are the most common structure a homeowner builds without a permit. A deck that moves when you lean on the rail is a safety item, not a cosmetic one.
5. Driveway, walkways, and retaining walls. Cracks and heaving in concrete are normal. A retaining wall that leans or bulges is not, and on a sloped Seattle or Tacoma lot it can be a five-figure repair.
6. Trees and vegetation. Branches touching the roof, ivy on the siding, and large trees within 15 feet of the foundation all go on the list. Roots find sewer lines, which is one reason the sewer scope below exists.
   
   

Roof and attic: items 7 to 10

7. Roof covering. Composition shingles last 20 to 30 years in our climate. Cedar shake, still common on older homes around Puget Sound, lasts less when it is not maintained. Ask the inspector for a rough age and the remaining life in years. A roof with five years left is a negotiating item.
8. Flashing, vents, and penetrations. Most roof leaks start where something passes through the roof, not in the field of shingles. Chimneys, plumbing vents, and skylights get the closest look.
9. Gutters and downspouts. Full gutters and disconnected downspouts are maintenance issues: cheap to fix and expensive to ignore. See item 1.
10. Attic. The inspector is looking for daylight, water stains on the underside of the sheathing, insulation depth, ventilation, and bathroom fans that vent into the attic instead of outside. Mold on the sheathing of a Western Washington attic is common and almost always a ventilation problem.
    
    

Structure, foundation, and crawl space: items 11 to 15

11. Foundation walls. Hairline cracks are normal in poured concrete. Horizontal cracks, cracks wider than a quarter inch, and cracks with one side higher than the other are not. They call for a structural engineer, which is exactly what the additional-inspection time in Form 35 is for.
12. Crawl space. Most Washington homes sit on a crawl space, and the crawl space is where the house tells the truth. The inspector should go in, not look in from the hatch. Standing water, a torn or missing vapor barrier, rodent droppings, and damp insulation hanging from the floor joists all go in the report. Our guide to water in the crawl space covers what each of those means and what it costs to fix.
13. Framing and floor structure. Sagging floors, notched or cut joists, and posts sitting on dirt instead of concrete pads. In older homes, look for joists that were cut to run plumbing or ducts.
14. Earthquake bolting. This one is Washington-specific. Homes built before the mid-1980s were often not bolted to their foundations. The inspector can see whether anchor bolts are present and whether the cripple wall is braced. A retrofit on a typical Seattle bungalow is a real cost, and it is a legitimate line on Form 35R.
15. Signs of past repairs. Fresh paint on one section of a foundation wall, new drywall in one corner of a basement, or a single patch of new siding. Each one has a story, and Form 17, the seller's disclosure, is where that story is supposed to be told. Compare what you see with what the seller disclosed on Form 17.
    
    

Systems: items 16 to 22

16. Electrical panel. The inspector pulls the cover and reads the label. Federal Pacific Stab-Lok and Zinsco panels are on every inspector's replace list because of documented failures to trip. A 100-amp service in a home with electric heat and an EV charger on the wish list is undersized. Double-tapped breakers and aluminum branch wiring also get flagged.
17. Wiring. Knob-and-tube wiring is still live in a share of Seattle, Tacoma, and Spokane homes built before 1950. It is not an automatic fail, but some insurers will not write a policy on it, and that is a question for your agent before the contingency expires.
18. Plumbing supply. Galvanized steel pipe, common before 1960, corrodes from the inside and shows up as low pressure at the top-floor shower. Polybutylene, used in the late 1970s through the mid-1990s, is on the replace list. Copper and PEX are fine.
19. Drains and the water heater. The inspector runs every fixture and watches how fast it drains. The water heater gets a date, a look for corrosion, and a check for the seismic straps Washington requires.
20. Heating. Furnace age and condition, the filter, the flue, and whether the heat exchanger shows cracks. Heat pumps are now the most common new installation in Western Washington, and the inspector checks the outdoor unit and the age of the system.
21. Cooling and ventilation. Fewer than half of Puget Sound homes have central air, so the inspector may only be checking a heat pump in cooling mode. Bath and kitchen fans should vent outside, not into the attic or the crawl space.
22. Fireplace and chimney. A level-one look at the firebox, damper, and visible flue. If the home has a wood-burning fireplace and you plan to use it, a chimney sweep's level-two inspection with a camera is a common add-on.
    
    

Interior: items 23 to 26

23. Walls, ceilings, and floors. Stains on ceilings below bathrooms, bubbling paint, and soft spots in the floor near tubs and toilets. Sloping floors go back to item 13.
24. Kitchen and bathrooms. The inspector runs the appliances that stay, checks for leaks under every sink, and tests the GFCI outlets. Caulk and grout are maintenance. A soft subfloor at the toilet is not.
25. Doors, windows, and safety items. Smoke and carbon monoxide detectors, which Washington requires in homes being sold. Windows in bedrooms that open and are large enough to escape through. Handrails on stairs with four or more risers.
26. Garage. The firewall and the self-closing door between garage and house, the garage door opener's auto-reverse, and the condition of the slab.
    
    

What the inspector will not check: items 27 to 30

A standard home inspection is visual and non-invasive. The home inspector does not move furniture, open walls, or run a camera through a pipe. The report describes defects and maintenance issues the inspector could see on the day. These four checklist items are yours.

27. Permits. Pull the permit history on the city or county website. A finished basement, a new deck, or a converted garage with no permit is a disclosure problem and sometimes an insurance problem. In Seattle, the permit portal is public and takes ten minutes.
28. Noise, light, and neighbors. Go back at a different time of day. A quiet Tuesday-morning showing says nothing about Friday night next to a bar, or the 6 a.m. flight path. This is also the time to walk the lot lines and compare them with the plat.
29. Flood, slide, and liquefaction maps. King, Pierce, and Snohomish counties all publish hazard maps. A home on a Seattle hillside or in the Kent valley may sit in a slide or liquefaction zone that changes both the insurance picture and the resale conversation.
30. The Form 17 cross-check. Read the seller's disclosure next to the home inspection report, and keep this checklist beside both. Anything the inspector found that the seller marked "no" or "don't know" is worth a direct question through your agent before you write your Form 35R.
    
    

The four Washington add-ons

Sewer scope. A camera run through the side sewer from the house to the city main, about $200 to $350. Seattle, Tacoma, and the older suburbs have miles of concrete and clay side sewers from the 1920s through the 1960s. In Seattle the homeowner is responsible for the line all the way to the main.

A broken or root-filled side sewer costs more than almost anything else on this list to replace. Order it on any home built before 1980, and on newer homes with large trees. If you are buying in Renton or another postwar suburb, assume the side sewer is original until the camera says otherwise.

Oil tank sweep. Many Puget Sound homes heated with oil before converting to gas or electric, and the tank is often still buried in the yard. A sweep with a metal detector locates it. A leaking tank is an environmental cleanup. Washington's Pollution Liability Insurance Agency runs a heating oil program that can cover cleanup for registered tanks. Whether the tank is registered and decommissioned is a question for the seller now, not after closing.

Septic inspection. If the home is not on city sewer, the septic system needs its own inspection by a licensed septic professional. That is the case across much of unincorporated King, Snohomish, Kitsap, and Thurston counties. Several counties, Thurston among them, require an inspection report as part of the sale. A failed drainfield is a five-figure repair that a general inspector cannot see.

Radon test. Radon risk in Washington is uneven. Spokane County and parts of eastern Washington test high. Most of King County tests low, with pockets.

A 48-hour test is about $150 to $300. Our winterizing guide covers the moisture and ventilation habits that keep a basement dry after you move in. Order the test on any home east of the Cascades and on any home with a finished basement anywhere in the state.

What is the biggest red flag in a home inspection?

Water where it should not be. Active moisture in the crawl space, stains on the attic sheathing, and efflorescence on a basement wall all point to the same thing. Water is behind most of the expensive defects a house can have: rot, mold, foundation movement, and failed framing.

The next two are a foundation that has moved, meaning horizontal or offset cracks and doors that no longer close, and an electrical panel on the recall lists. Those three can be deal breakers because the cost is both high and uncertain until a specialist looks. Nearly everything else on this list, including an old roof, galvanized pipe, and a tired furnace, is a repair with a known price. Known prices belong on Form 35R, not in a termination notice.

Should I attend the home inspection?

Yes, for all of it. Bring this home inspection checklist and tick items off as you go. The report arrives a day later and runs 50 to 80 pages with photos of every outlet. The walk-through is where the inspector tells you which three issues matter and which forty do not.

Bring a notebook, ask the home inspector what they would fix first if it were their house, and ask for a rough cost on any issues that worry you. Inspectors will not give estimates in writing, but most will talk.

How much does a home inspection cost in Washington?

A standard home inspection on a single-family home in the Seattle area runs about $450 to $700, with larger and older homes at the top of the range. Add $200 to $350 for the sewer scope, $150 to $300 for radon, and a similar amount for an oil tank sweep. A septic inspection varies by county and system but commonly runs $400 to $800. 

After the inspection: using what you found

The home inspection report gives you three paths under Form 35. Approve and move on. Ask for repairs or a credit on Form 35R. Or terminate and recover your earnest money.

The credit is usually the better ask: sellers resist managing repairs in a short window, and a credit lets you choose your own contractor after closing. Our seller credits guide covers the lender caps a credit has to fit under.

If you are in a competitive situation and weighing whether to shorten or drop the contingency, read our guide to waiving the inspection contingency in Washington first. Seattle real estate also has a tradition of pre-inspections before the offer, which we cover in Seattle pre-inspection trends. And if you want to catch some of this before you ever write an offer, our list of questions to ask when touring a house covers the first pass.

Frequently asked questions

Does the seller have to fix what the inspection finds? No. In Washington real estate contracts the seller has no obligation to make any repair. Form 35R is a request, and the seller can agree, refuse, or counter. Your leverage is your right to terminate.

Can I do a home inspection on new construction? Yes, and you should. New homes fail inspections on grading, flashing, and ventilation as often as old ones. Many buyers inspect twice: once before drywall and once before closing.

What is not covered by a home inspection? Anything the inspector cannot see or safely reach: inside walls, under carpet, inside sewer lines, buried tanks, septic systems, and chimneys beyond a visual look. Pests, mold testing, and asbestos testing are separate inspections by separate licensees.

How long does a home inspection take? Two to four hours for a single-family home, longer for a large or older house. The written report usually arrives within 24 hours.

Ready to inspect smart?

At Every Door Real Estate we walk every home inspection with our buyers and help you decide which add-ons a particular house actually needs. Then we write the Form 35R that gets a credit instead of an argument. Talk to us before your ten days start.