Locating a child care, preschool or school in many existing buildings would require that the entire building be seismically upgraded.
The city's seismic ordinance classifies the various building code occupancies into five "relative hazard" levels. Educational occupancies fall into the highest hazard level. Most churches worship areas are assembly occupancies, which are classified at the same high hazard level. So using space in a church for an educational occupancy wouldn't ordinarily trigger the requirement for a seismic upgrade. Retail, office, warehouse or manufacturing buildings are all classified as lower hazard occupancies than an E.
When the change in use is to a higher relative hazard occupancy, 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 educational occupancies, visit the Development Services Center or call a Life Safety Reviewer at (503) 823-1456.