ADU & DADU Construction in Spanaway, WA

ADU & DADU Construction in Spanaway, WA

Spanaway is an unincorporated Pierce County community with lot sizes that often work well for ADU construction. Many homes near Spanaway Lake and along the wider residential streets sit on lots large enough for a detached backyard cottage. The more modest lots closer to Pacific Avenue and JBLM are better suited for garage conversions. Spanaway's more affordable housing stock means building an ADU here gives you a strong return relative to property values. I have over 20 years in the trades and have been building ADUs across Pierce County since 2018.

Garage conversions in Spanaway typically run $78,000 to $165,000. A 2-car garage gives you roughly 400 to 450 square feet for a studio or one-bedroom layout with a full bathroom and kitchenette. For lots that can support a detached unit, a new ADU in the 400 to 700 square foot range runs $155,000 to $330,000. Rental demand in Spanaway is solid, especially with JBLM nearby. A finished ADU can bring in $1,100 to $1,600 per month. I handle design, engineering, and construction under one contract. My ADU construction page covers the full process.

ADU permits in Spanaway go through Pierce County Planning and Public Works. Pierce County adopted Ordinance 2025-516s to comply with HB 1337, allowing 2 ADUs per lot within the Urban Growth Area with a maximum size of 1,000 square feet. Side and rear setbacks are 5 feet. I handle the full permit package including site plans and utility connections. Some Spanaway properties are on septic, and I coordinate with the Tacoma-Pierce County Health Department to confirm system capacity before design begins.

If you have a Spanaway property with unused yard space or a garage you could convert, call me at (253) 392-9266 or request a free estimate. I will walk your lot, check setbacks, and give you a fixed-price proposal. Visit the Spanaway service area page for more.