Construction Design Criteria

Building Codes
The current and adopted building and design codes for the City of Tualatin are: Oregon Building Codes.

Seismic Zone
All of Tualatin is located in seismic zone D-1. (2007 OSSC, Chapter 16, Sub-Section 1613)

Basic Wind Speed
All of the City of Tualatin is wind speed 95 mph (x1.61 for km/h). (2010 OSSC Chapter 16, Section 1609, Figure 1609)

Wind Exposure Category
The architect or structural engineer responsible for the design of the structure shall determine the wind exposure as defined in the code (2007 OSSC, Chapter 16, Section 1609.4, or Section 1609.6, Figures 1609.6.2.1 and 1609.6.2.2)

Soil Bearing
Commercial/Industrial Projects
All commercial projects within the city or within the city's Urban Growth Boundary require a soils report by as part of the permit application submittal.

Single Family Dwellings
1500 PSF is the default soil bearing pressure. An increase to 200 PSF requires an engineer's site visit analysis and approval. Any increase to greater than 2000 PSF will require a site specific soils report.

Snow Loads
25 PSF Snow Load is the minimum design criteria. (2007 OSSC, Section 1608).

Flood Zones
The City of Tualatin has area that fall within the floodway and the 100-year floodplain of the Tualatin River. To determine if your site is within the flood zone, please contact either Engineer Associate Tony Doran (503-691-3035) or Project Engineer Dayna Webb (503-691-3036).