Design Information

The uniform statewide building code is the building code used throughout Virginia and supersedes all local building codes. The 2021 USBC can be found at the DHCD Virginia Website.

As of February 17, 2024, Shenandoah County is enforcing the 2021 edition of the International Codes with the 2021 Virginia Uniform Statewide Building Code amendments.  Click here to review the 2021 Code Update Presentation

Design Information

  • Frost depth is 24 inches from grade to bottom of footing
  • Ground snow load is 40 PSF
  • VULT Wind speed is 115 MPH, 3-second gust
  • The seismic design category is B
  • Severe weathering
  • Moderate to heavy termite damage
  • Winter design temperature, 16 degrees
  • Mean annual temperature, 50 degrees
  • Air freezing index, 0-1000
  • Ice barrier underlayment requirement, Yes
  • Under-slab vapor retarder, 10 ml
  • Climate Zone 4A

2021 Code Cycle Information

  • Fenestration U-Factor                            .30
  • Skylight U- Factor                                    .55
  • Glazed Fenestration SHGC                    .40
  • Ceiling R-Value                                        49
  • Wood frame Wall R-Value                     15 or 13+1
  • Mass Wall R-Value                                   8 / 13
  • Floor R-Value                                             19
  • Basement Wall R-Value                         10ci or 13
  • Slab R-Value                                             10ci, 4’
  • Crawl Space R-Value                             10ci or 13
  • Ceiling with Attics –  R-38 will satisfy the requirements R49 wherever full height of uncompressed R-38 Insulation extends over the wall top plate at the caves.
  • Ceilings without Attics – If roof/ceiling assembly does not allow sufficient space for required R-49 Insulation, R-30 uncompressed insulation shall extend over top plate of wall plate. This reduction of requirements shall be limited to 500 SF or 20% of the total insulated ceiling area, whichever is less.


  • Additional information can be obtained from the Plans Examiner at 540-459-6185.