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The City of Portland, Oregon

Development Services

From Concept to Construction

Phone: 503-823-7300


1900 SW 4th Ave, Portland, OR 97201

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The city's seismic ordinance classifies the various building code occupancies into five "relative hazard" levels. Warehouse or manufacturing buildings are classified as lower hazard occupancies than a B occupancy, for seismic purposes. Locating a B occupancy drinking/dining establishment in a building that shows in our permit records as a legal warehouse or manufacturing building could require that the entire building be seismically upgraded. Converting legal office space (also a B occupancy) or retail space (an M occupancy) to a B occupancy drinking/dining establishment would not generally require a seismic upgrade, since B and M occupancies are classified at the same seismic hazard level.

When the change in use is to a higher relative hazard occupancy (from warehouse or manufacturing) you are generally required to upgrade the entire building if more than 1/3rd of the area of the building is changed to that higher use. The area trigger for seismic is cumulative over time, so if a portion of the building has already been changed without requiring an upgrade, your proposed project may cross over the allowed thresholds. It is very important to research the permit history of any building that you are considering as a location.

For more information on seismic triggers and your project, visit the Development Services Center or call a Life Safety Reviewer at (503) 823-1456.