Climate Design Criteria

All new construction placed in unincorporated Gunnison County shall be constructed so as to meet the snow load requirements at the proposed building site. The value of ground snow loads at building sites shall be determined through

"2016 Colorado Design Snow loads," Prepared by the Structural Engineers Association of Colorado Snow Load Committee.

The report can be found on Sea Colorado. This report provides the recommended design ground snow loads which are intended to be used with ASCE 7 procedures for structural design. Once the ground snow load at the building site is determined, it must then be converted to roof snow loads according to ASCE 7, with appropriate treatment of exposure to wind, thermal properties of the roof, roof slope, unbalanced snow loads, drifting, and risk exposure.

Table R301.2(1) Climatic and Geographic Design Criteria
Ground Snow Load:

Varies. The value of roof (or other member ) snow load shall be equal to the "recommended basic snow load" as defined in the 2016 Colorado Design Snow Loads." prepared by the "Structural Engineers Association of Colorado, " ASCE 7 procedures shall be used to convert to roof snow loads.

Wind Design: 

  • Speed (miles per hour): 115 (ultimate design wind speed)
  • Topographic effects: no
  • Special wind region: no
  • Wind-borne debris zone: no

Seismic Design Category: 

  • B for the site soil classification D

Subject to Damage from: 

  • Weathering; severe
  • Frost line depth: 36 inches
  • Termite: none to slight

Winter Design Temperature: 

  • -20F

Ice Barrier Underlayment Required: 

  • Yes

Flood Hazard: 

  • 989, Resolution 89-31, 2011FIRM maps

Air Freezing Index: 

  • 3447 (BF-days-100 year)