Pre-Approved DADU Plans
Also known as: Pre-approved ADU library · SDCI Tip 116
A library of vetted DADU designs that bypass full architectural plan review for faster permitting.
Seattle's Pre-Approved DADU Plan Program offers a library of pre-vetted detached ADU designs that have already cleared the city's architectural and structural review. Choosing a pre-approved plan compresses SDCI review from 12–16 weeks to roughly 6–8 weeks because only the site-specific elements (foundation, utility tie-ins, ECA conditions) need to be re-reviewed. Bellevue, Tacoma and Olympia have launched similar programs in 2024–2025.