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Building An ADU In Portland

Building an ADU in Portland

If you live in Portland, you’ve probably heard of an ADU by now.

Otherwise known as a “mother-in-law apartment”, “granny flat” or just plain “studio”, an Accessory Dwelling Unit (ADU) is a second dwelling unit that stands on a pre-existing housing lot.

In Portland, we’ve see it done in a variety of ways: a second unit built from scratch, a converted garage, or a portion of the house being rededicated (like the attic or basement).

People build these for many reasons. For one, Portland’s scaled back regulations and added financial incentives make it one of the most appealing cities to build one. Two, ADUs are rented for an average of about $1,000/month, which, with the right tenant in there, can be a great way to pay back that mortgage. They’re also a great way to ease the housing crisis.

Thing is, it’s not as simple as, say, building a treehouse. Despite the scaled back regulations, Portland still has many requirements that you need to be aware of as you start planning. It may look daunting, but keep in mind how many people have done it already.

Acquire a Building Permit

Applying for a building permit includes a number of steps, mostly with obtaining the right documents. You may have to do some research on your property as well, to make sure it meets city restrictions.

Following that, you may be required to receive permits for separate utilities like electrical, plumbing and mechanical. These will need to be reviewed and passed by the Oregon Residential Specialty Code.

Meeting Design Requirements

ADUs need to meet certain dimensions to be considered ‘livable’. Building code requirements focus on things like materials, insulation and ceiling heights, all of which need to meet the city’s criteria.

A full list of these can be found through the City of Portland’s ADU Program Guide.

Passing Inspections

Once everything is taken into consideration, you’ll need to pass inspections by a few city officials, mostly from the Bureau of Development Services.

All in all, the process for permits and reviews could take one to two months. A lot of it depends on having your proper documents in place.

Some people rush into construction, without having everything approved. We highly recommend going through the process legally, both for the safety of your tenants as well as your own peace of mind.

We know the process seems daunting, and that’s why we encourage people to share their ideas with us. We can review the upcoming steps and walk you through the application process, ensuring you have everything you need to start building.