FAQ – Portland ADUs & Backyard Cottages

Thinking of building an ADU in Portland? Be sure to check out our “ADU 101” and “How Much Does It Cost To Build An ADU?” posts as you’re getting started.

Meanwhile, here are answers to a few frequently asked questions, drawn directly from the City of Portland’s ADU Program Guide (as of May 2015), a must read for anyone considering an ADU project.

Q: Is now a good time to build an ADU in Portland?

A: Yes. The City of Portland is waiving system development charges (SDCs) for ADU projects whose building permit application is submitted before July 31, 2018 (provided that occupancy begins before June 30, 2019). This is a big deal, as the cost of SDCs can easily reach five figures.

Q: How big can my ADU be?

A: The maximum size is no more than 75% of the living area of the house or 800sf, whichever is less.

Q: How tall can my ADU be?

A: No more than 18 feet high.

Q: How much space can my detached ADU take up?

A: No more than 15% of the total site area.

Q: What are the setback requirements for my ADU?

A: Detached ADUs must be set back 60 feet from the front lot line or 6 feet behind the house.

Q: Do I have to provide parking for my ADU?

A: No additional parking is required.

Q: Do either the main house or the ADU need to be owner occupied?

A: Nope!

Q: How much does it cost to build an ADU in Portland?

A: See our post, “How Much Does It Cost To Build An ADU?

Q: What else should I consider?

A: See our post, “ADU 101.

Good luck with your project. Please contact us if you’d like us to build it!

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