Portland ADU Guide, 2022. Two Per Lot and Less Restrictions

portland adu guide

Now that Accessory Dwelling Units (ADUs) are allowed in every city in Oregon, Portland will likely see an influx of home additions and new ADU construction, especially with the passing of the city’s Residential Infill Project (RIP) that went into effect this August 2021.

If you’ve been toying with the idea of adding an ADU to your property, the new ADU guidelines will make it easier than ever before. Use the link to see the new 2021 official ADU rules. It is only six pages long, but packed with all the necessary information to get started. Additional Dwelling Units can enable you house a family member or make steady passive income, and you’ll also help manage Portland’s density problem.

Two ADUs Approved for Most Lots

One of the new code changes now allows two ADUs per property rather than only one (on most lots). This means you can renovate your basement AND spiff up your attic space or do an addition above your garage. You can also put two ADUs on your property in a single detached building, creating in-effect, a small triplex.

portland adus
Credit to the fabulous Neil Kelly, a local Portland ADU designer.

Duplex Owners Can Now Add an ADU

Duplex owners, in most lot sizes, can now add an additional ADU to their property, either as an add-on or a detached dwelling.

Basement ADUs Just Got Bigger

Until now, the maximum square footage for converted basement ADUs was 800. A problem, because many basements in Portland are larger than 800 square feet. The new allowable square footage for this type of ADU is 1,000, giving homeowners more flexibility and options.

Entrance Regulation Changes for ADUs

Each dwelling on a property requires its own separate entrance. This hasn’t changed. What has changed is that each property is now allowed two street-facing entrances rather than only one.

ADU Parking Regulation Changes

The city has also lifted the off-street parking requirement for homeowners who add ADUs to their properties. This means you don’t have to reserve any driveway or garage space or have either on the property. One caveat: If you add an ADU to a space previously meant for parking, you’ll be responsible for closing the ramp cut in the curb.

Wheelchair Accessibility and Waivers for ADUs

Portland requires that at least one of your structures be wheelchair accessible. There are some exceptions to this, and your property could be waived of the requirement if it meets any of the following.

  • A lot with an average slope of 20% or greater
  • A lot with a rise more than 3 feet between the highest point on the street and the lowest point at the front setback
  • A conversion of an existing house at least 5 years old to an ADU
  • A conversion of an existing ADU at least 5 years old

ADU Lot Requirements and Other Considerations

The ability to have two ADUs per property will be a blessing for many homeowners. If you’re thinking of adding one or two to your property, be sure you’re aware of the lot requirements. The table below gives an at-a-glance view of what you can expect, depending on your zone.

For more information about Portland’s new codes and zoning laws specific to ADU lot requirements and more, view this report. To find out the zoning of your particular property go here and type in your address.

Portland’s RIP – Residential Infill Project

In 2020, Portland passed the Residential Infill Project (RIP) with its sights set on managing the rising population density in the area. It went into effect August 2021.

The goal of the Residential Infill Project is to find ways to better utilize unused space in the city whether through oversized homes and backyards, empty lots, or older homes that can be demolished. The plan intends to accommodate its growing population without increasing its footprint.

Portland is growing, without a doubt. Owning ADU property is a way to be part of the solution to the city’s density problem. Understanding the rules around ADUs will help you make smart decisions about add-ons, renovations, and purchasing.

The beauty of the RIP is that it puts the power in the hands of Portland homeowners rather than developers.

Buy an ADU-Ready Property

If you’d rather not face the disruptive undertaking of renovation or construction, think about buying a home with an existing ADU. Use our smart home search site to find Portland homes for sale with built-in additional living quarters.

With the new codes and regulations, you can always add another ADU after you’ve settled in. If you plan to use your ADU for passive rental income, here’s a heads up about the 2021 game-changing Portland rental laws.

Not sure which route is best for you? Learn more about the specifics of finishing your basement or attic and how to reduce costs.

Work with ADU Experts

Our top 1% Portland buyer’s agents and seller’s agents have tons of experience helping Portlanders purchase and sell homes with ADUs and are standing by to help answer your questions.

September 24, 2021

Stephen FitzMaurice

Stephen FitzMaurice, Realtor is a top 5% real estate agent in the U.S. A Principal Broker in Oregon, Managing Broker in Washington, he has been licensed since 2003 for residential real estate sales. Call his team in Oregon at 503-714-1111 or in Washington at 360-345-3833.

4% max to sell a home in Portland and SW Washington.
4.25% max to sell a home in Salem and Bend.
Over 2,000 homes sold.