General Design Criteria


  1. OSSC section 1613 is used to design for earthquake loads. Seismic design category shall be "D" unless site specific conditions increase design category to "E or F" (reference codes American Society of Civil Engineers ASCE/SEI 7-05). Residential projects falling under the ORSC shall use seismic zone D1.
  2. OSSC section 1609.1.1 is used for wind design. The design ultimate wind speed is determined from figures 1609A, 1609B, or 1609C See section 1609.3.1 for additional design information. Residential projects falling under the ORSC shall use a design wind speed of 95 miles per hour (3 second gust). See section R301.2.1.3 for addition all design information.
    1. Most areas of Klamath County can be classified as wind exposure category C. However, some areas may meet the criteria for exposure B (typically within Urban Growth/City Limits). The design professional is responsible for justifying the exposure selected for the specific areas of construction.
  3. Soils bearing pressure is 1500 pounds per square foot, unless justified by a soils report. A lesser bearing pressure may be required in specific locations.
  4. Ground snow loads are site specific and are published from the Structural Engineers Association of Oregon "Snow Load Analysis for Oregon" 3rd edition Dec 2007. However design snow loads shall be a minimum of 20 pounds per square foot, with factors: slope, exposure, thermal, importance, drifting, etc.
  5. Rainfall design is site specific and based on U.S. Weather Bureau Technical paper Number 40: 100-year 60 minute storm. Klamath County has four rainfall zones (3, 9, 10 and 13).
  6. The frost depth for foundation design is 24 inches below grade.
  7. Flood Loads section 1612 (if applicable).

Building permit fees can be determined from each application form, ball park (project valuation <$400K+2.5 % valuation, over $500K+2%) typically fees have not exceeded these ballpark figures.