1900 SW 4th Ave, Portland, OR 97201
Residential Engineering - General Information
Your project must be designed to meet all the requirements of the building code. This usually means that a full foundation with footings to the frost depth, and a complete lateral force resisting system are required.
The Building Code has two options for showing the building will resist lateral loads (wind and earthquake forces).
Note that plans and calculations will not be required to show that a structure will resist wind and earthquake loads if it can be considered a "minor" addition. See Lateral Bracing for Minor Dormer Additions.
1. Prescriptive Path
In the prescriptive path, the Code provides conservative method of construction to ensure the building will resist wind and earthquake loads using braced wall panels, continuous sheathing and tie-down anchors. If your structure is designed to meet prescriptive requirements for lateral design, you will need to include separate wall bracing floor plans. A guide provided by the State of Oregon can be viewed here.
2. Engineered Path
If your design does not meet the prescriptive path, a licensed engineer, certified in Oregon, will need to prepare engineering calculations that shows that the structure can resist the lateral loads.
There are also requirements for resisting gravity loads, and any beam over 10’ long or supporting a point load must also be submitted with beam calculations.
Visit the Plan Review Staff at the Development Services Center for more information on prescriptive and engineered paths.