New pre-approved ADU plans now available

News Article
This photo depicts a small accessory dwelling unit surrounded by trees and other vegetation.
Development Services is pleased to offer plans for detached ADUs that meet certain building code requirements. They also support the City’s housing goals and the bureau’s equity goals. Homeowners considering building a detached ADU can use these free plans and save time in the permitting process.

Recognizing the complexity of the permitting system, particularly as more housing is needed in Portland, the goal of this effort is to provide pre-approved plans that can reduce the resources and time needed to receive a permit.

These pre-approved plans were provided by the City of Eugene, with minor changes. The City of Portland expresses appreciation to the City of Eugene, which shared its developed plans at no cost. Similar pre-approved plans are in use in other cities in Oregon, including Bend and Salem.

There are four options of this free plan to choose from that vary in roof and foundation type:

An ADU with a gable roof and concrete slab on grade floor and foundations

An ADU with a shed roof and concrete slab on grade floor and foundations

An ADU with a gable roof and wood-framed floor and crawl space

An ADU with a shed roof and wood-framed floor and crawl space

Homeowners who seek to build a detached ADU are not required to use one of these pre-approved plans. However, adherence to one of these pre-approved plans will not require review for life safety or structural requirements of the Oregon Residential Specialty Code.

There are several other requirements that must be considered when applying for a permit to build a detached ADU, such as zoning allowances, utility connections, development in flood hazard areas, and other factors. Separate electrical, plumbing and mechanical permits must be obtained. The construction of a detached ADU may incur system development charges.

More information about these considerations and other requirements when adding an ADU can be found on the Accessory Dwelling Units web page.

This is the first of many efforts that the Bureau of Development Services (soon to be a part of Portland Permitting and Development) will undertake, through regular community engagement, to provide pre-approved plan sets to help homeowners receive permits more efficiently.


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