What Window Replacement Costs in the Seattle Area

Insert replacement in the Seattle area typically runs $700–$1,400 per window installed. Full-frame runs $1,200–$2,500. On a typical house of 12–20 windows that is roughly $10,000–$25,000 or $18,000–$45,000 across the whole house.

The gap between those two numbers is one decision, and it is worth understanding before you compare a single bid.

Insert or full-frame

An insert replacement fits a new window inside the existing frame. The old sash comes out, the frame stays, your interior and exterior trim is undisturbed. It is faster, cheaper and genuinely correct when the existing frame is sound, square and was flashed properly when it was built.

A full-frame replacement takes everything back to the rough opening and rebuilds the water management: sill pan, head flashing, weather barrier integrated with the wall, then the window, then new trim. It costs more because it is more work, and it is the only honest option when there is rot at the sill, the opening has racked out of square, or the original install was never flashed.

A bid that does not say which one it priced is not a bid you can compare.

What moves the per-window number

• Frame material. Vinyl is the regional default and the cheapest competent option. Fiberglass runs roughly 30–50% more, moves less with temperature and takes paint. Wood-clad costs more again and belongs where the interior trim is the point.
• Size and operation. A large slider or a casement with a crank costs more than a fixed picture window of the same area. Anything requiring two people to lift costs more to set.
• Access. Second-storey and gable windows need staging. A dozen ground-floor windows and a dozen spread over three storeys are not the same job.
• What is behind the trim. The genuine variable. Soft sills and damaged framing are found at tear-out, which is why we open an inspection hole before quoting rather than discovering it on install day.

All at once, or a few at a time

Per window, doing the whole house at once is cheaper — mobilisation, staging and setup are paid once rather than three times, and ordering a full set usually prices better than three small orders.

Doing them in phases is still reasonable if cash flow demands it. If you phase, start with the elevation taking the weather — south and west here — and with any window showing fogging between the panes, which means the seal has failed and that unit is doing little thermally.

What a comparable bid includes

• Which method: insert or full-frame, stated plainly
• Frame material, series and the U-factor on the glass
• Who disposes of the old units
• Interior and exterior trim: repaired, replaced or left
• An allowance for rot repair, and the rate if it exceeds it
• Permit, where the work triggers one

The twelve questions cover the rest of what separates a cheap bid from a vague one.

Windows and the wall around them

Window flashing has to integrate with the wall’s weather barrier. If siding is also near end of life, doing both together means one crew owns that junction instead of two trades meeting at it — and it is the single most common place exterior work leaks years later. The siding cost guide and cladding comparison cover that half.

Get a number for your windows

We replace windows across Snohomish and King County. The free estimate says which method your openings actually need before it says what they cost.

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