If you’re planning to convert your basement, garage, or backyard into an ADU in Portland, a newly updated code guide lays out technical requirements for permit submittals and when licensed contractors are required.
Portland’s Bureau of Development Services updated the city’s ADU building code guide in August, with approval signatures from Natalie Didion, director/building official, and Eric Kutch.
The guide explains how Portland applies Oregon’s residential code for two-family dwellings to ADUs, and lists allowed alternatives and reductions for existing conditions. It applies to every type of ADU—basement conversions, garage conversions, attached additions, and detached backyard cottages.
Electrical: no DIY, no shared circuits
One of the most consequential rules involves your electrical system. The guide requires that ADU circuits be “completely independent of, and share no loads with, the main dwelling unit.”…