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System Development Charges for Accessory Dwelling Units Temporarily Suspended


This is an update concerning a recently passed City Council resolution and subsequently approved

ordinances regarding Accessory Dwelling Units (ADU). The ordinances have temporarily suspended

System Development Charges (SDC) for new ADUs. The goal of this action is to create incentives for

the development of ADUs.

The initial resolution directed all affected bureaus (Water, Parks and Recreation, Environmental Services

and Transportation) to implement the resolution by April 15, 2010. Please note that the Bureau of

Development Services is responsible for the development review process, but does not assess a SDC. All

other non-SDC development related fees are due at time of permit issuance. Questions about SDC’s

should be directed to the individual Bureaus (Water, Parks and Recreation, Environmental Services, and


Accessory Dwelling Units (ADU) are defined by the Portland Zoning code as a second dwelling unit

created on a lot with a house, attached house or manufactured home. The second unit is created auxiliary

to, and is smaller than, the house, attached house (rowhouse) or manufactured house.

Here is a link to the resolution:

Proposals to build detached ADUs are reviewed through the New Single Family Review process. View

the application package and process at

Permits to convert existing living space to an accessory dwelling unit are applied for in the Development

Services Center, Tuesday through Friday, 8:00 a.m. to 3:00 p.m. View the Minimum Submittal

Requirements for an ADU at

The Bureau of Development Services has a Program Guide available that explains what constitutes an

Accessory Dwelling Unit and how to permit one on your property. View the program guide at

To review a general summary of System Development Charge information you can visit at Please note that SDC fees are typically

revised every July 1.

If you have process related questions or concerns, please contact Kareen Perkins, Permitting Services and

Resource Records Manager, at (503) 823-3622.

«Print this copy in PDF format»




August 5, 2010 at 10:50 AM

Why in the world would you want to "encourage" ADU's? You enjoy crowded living spaces over open space and privacy? I'm assuming none of YOUR neighbors have constructed 30 foot tall ADU's with balconies that encroach on your tranquil living space and create eye sores for several blocks.



October 22, 2010 at 1:59 AM

ADU's are a great way to maximize land use by increasing density and therefore reducing urban sprawl.

They increase short term economic stimulus by creating construction related jobs (architects, surveyors, contractors, building inspectors, building materials sales people, etc). And in the long term they provide increased property tax revenue.

Detached ADU's have an 18' height restriction and must have an appearance that matches the style of the primary house. So they look residential and reduce the need for apartment complexes which often are eyesores.

Each lot has an open space minimum requirement and ADU's can't be built if they would exceed the allowed lot coverage. They also offer people who would normally be stuck living in apartment complexes the chance to experience more open space and privacy than they would have otherwise.



April 20, 2011 at 12:33 PM

ADUs are very efficient- they manage to turn several properties into dumps with merely one building. In the name of a strong community, ADUs destroy the aesthetic qualities of as many backyards as possible. Bravo! A great way to wreck communities.

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