The ground snow load in Eugene is approximately 11 psf at a elevation of 420 feet (OSSC 1608.2.2; http://snowload.seao.org). The ground snow load must be modified in accordance with ASCE 7-16 Table 7.2 for higher elevations. However, the minimum snow load and minimum sloped roof snow load of 20 psf typically govern design (see OSSC 1608.2.3 and 1608.2.4). An additional rain-on-snow surcharge load of 5 psf applies for flat roofs and roofs that constrain runoff. (OSSC 1608.2.5)
Basic design wind speeds for Eugene are as follows (OSSC Table 1609.3):
|Risk Category||V (mph)|
Most structures in Eugene are assigned Seismic Design Category D in accordance with OSSC 1613.2.5. Seismic design parameters should be obtained from https://hazards.atcouncil.org/.