Seattle's building permit records are public, searchable, and almost entirely ignored by homeowners — which is a shame, because for a house you are about to buy, or one you already own and know little about, they are the closest thing to a medical history the building has.
Here is what to look for and what each finding actually tells you about the roof.
Before any permit detail, the construction date tells you the probable decking type, and decking is the single largest cost variable in a re-roof.
Homes built before roughly 1950 in Seattle were commonly sheathed with spaced boards — skip sheathing — because the original roof was cedar shake, which needs airflow underneath. That substrate does not properly support modern asphalt shingles and typically needs overlaying with new panels, which can add several thousand dollars to a project. Homes from the 1950s onward generally have plywood; from the 1980s onward, usually OSB.
None of this is certain, because roofs get redone and decking sometimes gets replaced along the way. But it tells you which scenario to ask about.
A roofing permit record gives you the date of the work, which is the roof's real age rather than the seller's estimate. That matters: asphalt roofs in Seattle typically enter their decline phase between years fifteen and twenty-two, and a roof described as recent that turns out to be from eighteen years ago is a different purchase.
Multiple roofing permits at different dates suggest layers. A permit that references sheathing or structural work tells you decking was addressed, which is genuinely good news — it means someone looked.
The gap is the interesting part. If a listing says the roof was replaced in a given year and no permit exists for it, either the work was unpermitted or it did not happen as described. Both are worth knowing before closing.
Several other record types matter more than people expect.
Attic conversions and dormer additions. These change the roof structure and the ventilation strategy simultaneously. A converted attic means the ventilated cold attic that used to protect the deck may no longer exist, and if the conversion was done without a properly designed vented or unvented assembly, condensation problems follow. Look for whether insulation and ventilation were part of the permitted scope.
Solar installations. Panels mean roof penetrations, and they mean that removing and reinstalling an array is now part of any future re-roof cost. Ideally the roof was replaced immediately before the panels went on; if the permit dates show panels installed on an already-old roof, the next owner inherits an expensive sequencing problem.
Skylight additions. Each one is a hand-flashed penetration and a potential leak point. A skylight added long after the original roof, particularly by a general contractor rather than a roofer, deserves scrutiny.
Siding replacement. Worth cross-referencing, because roof-to-wall flashing lives at the junction of those two systems, and siding work is when kickout flashing failures are typically discovered.
Permits name the contractor. That lets you check whether the company still exists, whether its Washington state registration is active, and whether the bond and insurance were current at the time. A workmanship warranty from a company that dissolved six years ago is not an asset, and knowing that changes how you weigh a seller's warranty paperwork.
Permits establish that work was permitted and inspected. They do not establish that it was done well. A permitted re-roof can still have reused flashing, missing kickouts, no drip edge, and inadequate ventilation, because inspection scope is limited and much of the assembly is covered by the time anyone looks.
So the records are a starting point rather than a verdict. They tell you what questions to ask and which claims to verify. The roof itself still has to be inspected — ideally from the attic side, where the evidence of how it has actually performed is written on the underside of the deck.
A permit entry contains more than a date, and the fields that matter are not always the obvious ones.
Issue date versus final inspection date. These are different, and the gap between them is informative. A permit issued and never finalled means the work was started under permit but never signed off. That is an open permit, and it is a genuine problem at sale — buyers and lenders notice, and closing an old permit years later can require exposing work that has long since been covered.
Scope description. Look for whether sheathing, decking, or structural work appears. A permit that mentions only re-roof tells you the surface was replaced. One that mentions sheathing replacement tells you somebody looked at the deck, which is meaningfully better news.
Valuation. Permits typically record a declared job value. It is not precise, but a re-roof declared at an implausibly low figure alongside a large roof area suggests either a very limited scope or an under-declaration, and either is worth asking about.
Contractor of record. Check whether the company still exists and whether its registration is active. A workmanship warranty from a dissolved business is a piece of paper, and that changes how you weigh warranty documents a seller provides.
Homeowners often treat a missing permit as a technicality. It becomes concrete in four situations.
At sale. Washington sellers complete a disclosure statement covering known work and defects. Unpermitted work is a disclosure item, and buyers routinely request either that it be permitted retroactively or that the price reflect the risk. Retroactive permitting of covered work can mean opening things back up.
In an insurance claim. Carriers may examine whether work was performed to code and permitted, particularly where the claim relates to the workmanship of that work.
In a warranty claim. Manufacturer warranties are conditioned on proper installation, and unpermitted, uninspected work weakens any argument that installation was compliant.
In a future project. Applying for a permit on a house with an open or missing prior permit can surface the older issue, sometimes at an inconvenient moment.
None of this is catastrophic on its own. It is simply a cost that has been deferred rather than avoided, and knowing about it before you buy or before you sell is what lets you price it deliberately.
The sequence that gets the most value out of twenty minutes of research:
Pull the record before the inspection, not after. Note the build year and infer the likely decking type. Note every roof-related permit and its date, and note any attic conversion, dormer, skylight, or solar permit, since each changes the roof assembly. Then hand that summary to your inspector and ask them to confirm or contradict it on site.
Two contradictions are worth chasing hard. A seller stating a roof age that the permit record does not support. And a roof that visibly has two layers where only one re-roof permit exists, which suggests a re-cover was done without one.
Records are a starting point, not a verdict. A permitted roof can still have reused flashing, no kickouts, and no drip edge, because inspection scope is limited and most of the assembly is covered by the time anyone looks. What the records give you is the list of questions worth asking.
This post is part of our in-depth coverage of roof replacement in Seattle.
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