Home Remodeling in
University Place, WA

University Place allows up to two ADUs per lot alongside a detached house. On a lot smaller than the minimum lot size for its zone, only one of those can be detached.

An ADU can be attached, a separate cottage, or part of a detached building such as a unit over a garage. Each can be up to 1,000 square feet, and the city can allow more if the unit fills a single floor of an existing multistory building.

The detail is in how a detached ADU fits into the side or rear yard. A building with an ADU above it, often called a carriage unit, is limited to a 600 square foot ground floor footprint. A ground floor ADU larger than 600 square feet means no other accessory buildings, such as a garage or shed, in the side or rear setback.

Detached units in those yards keep five foot side and rear setbacks, with nothing, eaves included, closer than three feet to a property line. They are limited to 24 feet at the ridge and 10 feet at the top of the wall where they sit in a required yard, and must be at least five feet from the main house. Only one detached ADU can use the reduced setbacks.

Parking depends on location and lot size. Within a half mile walk of a major transit stop, no parking is required. Elsewhere it is one off-street space per ADU on lots of 6,000 square feet or less, and two per ADU on larger lots, placed to the side or rear where possible.

An ADU goes through a normal building permit. Before that permit is issued, the owner records a notice on the property title with the Pierce County Auditor acknowledging the ADU. The city last updated these rules in 2025.