The following information must be submitted when applying for a permit to convert a garage, attic or basement of an existing one or two family dwelling to living space. Since every project is unique, there may be some situations where you will be asked to provide additional information.
It is recommended to visit or call the Planning and Zoning staff (503) 823-7526 and Buildings staff (503) 823-7310 at the Development Services Center early in the planning of your project.
Site Plan (Scale site plans to most appropriate scale, e.g. 1”=10’ or 1/4”=1’)
To submit for a permit, bring the completed building permit application and four (4) copies of site, architectural and structural plans (for the area of proposed work and areas affected by such work) along with intake fees to the Development Services Center.
(1) Evaluating Existing Space
In unfinished areas, existing features such as ceiling heights, windows, stairs and insulation may not meet current building code requirements for finished space. These conditions could make it expensive, difficult or even impossible for you to change your attic, basement or garage into living space.
(2) Garage Conversions
You will need to show how you will provide the required parking space since parking in your driveway alone may not meet this requirement.
If your garage is detached and you want to convert it to living space, it may not meet setback requirements since the zoning code may not allow living space to be placed in the setback areas, even if it allows the garage to be in that location.
A detached garage may have structural deficiencies that would need to be upgraded in order to meet building code standards.
If your project requires construction in the public right-of-way, then the Portland Department of Transportation will review the project, and issue a separate transportation permit for this work as well. For more information about right-of-way requirements, contact the Portland Department of Transportation at (503) 823-7002.
3) Attic & Dormer Additions
If converting attic space to living space would mean raising the roof, the zoning code height regulations may affect your project. See information on Dormer Additions.
(4) Second Sink Covenant
If your project will add a kitchen, such as a bar kitchen in an entertainment area, you may need a Second Kitchen Covenant. This document is a statement of understanding that the addition of this facility does not create another dwelling unit, and that the structure is still a single-family dwelling. If you are unsure if your project will trigger this requirement, please contact Planning and Zoning staff for additional information. If required, this document must be recorded with Multnomah County before your permit can be issued.
(5) Engineering Calculations
When the scope of work will change the structural load in the house, it is important that you submit engineering calculations that show the continuity of the load path from floors or other affected members all the way to the foundation of the house.
You must determine if the existing attic floor structure is strong enough to carry the additional weight of people and furniture. It is very common that when tracing floor loads from the converted attic, it is the beam in the basement that will be overstressed. Situations like this are required to be resolved as part of the permit application.
(6) Adding a Bathroom to an Unfinished Basement
If you are adding a bathroom in the basement but intend to leave the remainder of the basement unfinished, the entire basement does not have to comply with these conversion standards. However, the ceiling height in the bathroom must comply. In addition, the stair to the basement and a three foot wide path through the basement from the stair must meet the headroom and other dimensional requirements noted in the conversion brochure. The other requirements listed (including exterior wall insulation, storm windows and egress windows) are not required if no other habitable space is proposed in the basement.
If your house is located in a floodplain, there are restrictions that may limit your ability to add or to significantly improve your house without retrofitting it to be flood resistant. Please contact Site Development staff at (503) 823-6892 to discuss your project.