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Woodlawn ADU

New Portland ADU Rules

If you’re a Portland homeowner thinking of adding an accessory dwelling unit to your property, we have some good news for. Building that ADU is about to get a lot easier. Here’s a look at some new Portland ADU rules, as well as others affecting the whole state of Oregon.

From parking requirements to limits on the number of units, Portland homeowners have had to grapple with a wide range of regulations when it comes to adding an ADU to their property. Now a lot of that is about to change. Several ADU rules will soon be easing for Portlanders — as well as folks across Oregon. Here’s what you need to know…

Residential Infill Project

Many of the new Portland ADU rules are the result of the city passing what’s called the Residential Infill Project. The project is aimed at revamping the types of housing permitted in Portland neighborhoods, in part to better manage density.

The new rules will make it easier to build ADUs, allow for more ADUs overall, and create more housing options.

New Portland ADU rule: Two ADUs on a single property

portland adu rules: multiple adus

Under the code changes, Portland will become the first city in the country to allow for two ADUs to be built on a single property, in any configuration. Previously, only one was allowed. Other states and cities currently allow for two ADUs, but they place restrictions on layout.

In addition, two ADUs can also be built in a single detached accessory building, essentially dividing a detached ADU into separate units.

This change gives homeowners much more flexibility when it comes to ADU construction and can allow for more rental income if you choose to create rentable ADU units.

New Portland ADU Rule: Accessibility/Visitability

portland adu rules: brown detached adu

If you do decide to build a second ADU, one of the three structures on the property (main living structure, or either ADU) needs to be accessible by someone in a wheelchair. In other words, it needs to meet disability or “visitability” requirements.

Some exception do apply. If your property meets any of these, the visitability requirement can be waived:

  • The conversion of an existing accessory structure that is at least 5 years old
  • The conversion of a space in a house that is at least 5 years old, to an accessory dwelling unit
  • Lots with an average slope of 20 percent or greater
  • Lots with a rise that exceeds 3 feet between the highest elevation along the street line and the lowest grade measured at the front setback

New Portland ADU rule: Lifting of off-street parking requirements

portland adu rules: off street parking
photo credit

Ensuring adequate or additional off-street parking has long been a requirement if you wanted to build an ADU in Portland. Under the rule changes, all off-street parking requirements for residential zones are eliminated.

In other words, if you build an ADU or even a second one, you no longer need to have or create parking spots for them. So, if you’re thinking of converting your garage to an ADU in order to generate rental income or for another purpose, you don’t need to add another off-street parking space. If as part of building the ADU, you get rid of an existing parking spot and you’re left with a cut in the curb previously intended for cars, then you’ll be required to close that up and remove the ramp.

But by easing this rule, homeowners now will have more flexibility to repurpose the part of their lot that may have previously been used as a driveway or for parking. Now that space can be used for things like landscaping or for part of their new ADU structure.

Other Portland ADU rule changes

More duplex flexibility. Going forward, homeowners will be allowed to add a detached ADU to a property with an existing duplex. Previously, one could be erected only next to a single family house.

basement adu

Basement ADUs can now be larger. The maximum square footage for a converted basement ADU is being increased from 800 to 1,000. Many basements in the Portland area are greater than 800 square feet, so this will allow homeowners to use more of their basement for an ADU.

Two street facing entrances. Up until now, homes in the Portland city limits weren’t allowed to have two street facing entrances. The ADU entrance had to be sort of tucked behind the structure, away from the street. The new rules lift that restriction.

For more information on these ADU rule updates, you can check out this post from local ADU advocate Kol Peterson.

Related posts

To discover more about common ADU types and ideas on how to help plan and budget for one, check out: