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Garage conversion ADUs in Seattle

A legal unit inside the garage you already have, with new insulation, windows, kitchen, bath and an upgraded slab where needed.

Check what my lot allows

Garage converted with French doors and a window, car parked in front

Why convert a garage?

The structure is already there, so a conversion often costs less than a new cottage, and Seattle does not require off-street parking for ADUs, so the lost garage space does not need replacing.

Empty converted garage interior with skylights and garden windows

What does a garage need?

Moisture and level checks on the slab
New wall and ceiling insulation
Egress windows and an entry door where the garage door was
Sewer and water lines and an upgraded panel

What can surprise owners?

Older garages often sit right on the property line. Conversions of existing structures can keep that setback, but fire rules still apply to walls near the line.

Converting a Seattle garage

Conversions of existing structures can exceed the size cap that applies to new ADUs. Older garages near the lot line still need fire-rated walls.

Is your lot ready for an ADU?

Send your address and a sentence about what you want. We look up the zoning, setbacks and utility routes and reply with the ADU types that fit.

We build in Seattle, WA.