How do I build an ADU in Portland, OR?

January 4, 2024


Accessory dwelling units (ADUs) go by many names, including guest homes, granny flats, or in-law suites. For customers looking to build an ADU in Portland, Oregon, we’ve got you covered. Relevant Buildings has built homes and ADUs throughout Oregon and Washington. The ADU process involves four steps: design, financing, permitting, and building. Relevant Buildings offers assistance with every step to help make the ADU build process as easy as possible.

ADU in Portland




The first step is to design your ADU. We have several ready-made container home designs to get you started. Using one of our standard models is a great way to reduce design costs and timeline. While Relevant Buildings primarily builds container homes, we also offer stick-built ADUs for lots that are too narrow to deliver a prefabricated container home. Whatever your design needs are, we work with you to come up with a plan that fits your vision and your budget.


ADU builder in portland oregon city washington

Suite Spot River 40




For customers who plan to use financing for their ADU build, Relevant Buildings has partnered with a handful of different lenders who can help fund your project. The best way to learn about your financing options is to contact us on our Tour/Contact page.





ADU in Portland

De Lux River 20


Permitting is typically where the headache starts in the build process. Thankfully, Relevant Buildings can manage permitting on your behalf. The permit process takes roughly 12 weeks, depending on the local jurisdiction’s review timelines.

If you plan to build an ADU in Portland, then you’re in luck. The City of Portland recently updated their zoning code to make it easier than ever to build an ADU. Most residential areas in Portland allow for up to two ADUs per lot. The main challenge is making sure you have enough space on your property to fit an ADU. We can perform an initial zoning check on your property free of charge to confirm whether or not your local zoning code will allow you to build an ADU on your lot.


Pre-fab Homes Prefabricated houses Off-site construction

Ramona 40


Finally, the last step is to build your ADU. For our prefabricated container homes, we’re able to start the build process at the same time the site work is happening. This makes the overall process quicker than building a typical site-built home.

Site work includes clearing, excavating, foundation work, decks, and connection to utilities. Relevant Buildings is able to offer assistance with site work for local projects. Some customers choose to hire their own contractors to complete the site work.

After the foundation is complete, we then deliver your Relevant ADU. Some of our ADUs require additional work on site to complete the home, but generally the home is finished within a few weeks after delivery.


If you want to learn more about building an ADU in Portland, or anywhere else in Oregon or Washington, you can contact us on our Tour/Contact page. We’re always happy to help!


Featured ADUs: SADU 20, Suite Spot River 40, De Lux River 20, Ramona 40