Section 270. Chapter 16 Structural design  


Latest version.
  • A. Change Section 1609.3 of the IBC to read:

    1609.3 Basic wind speed. The ultimate design wind speed, Vult, in miles per hour (mph), for the determination of the wind loads shall be determined by Figures 1609A, 1609B, and 1609C. The ultimate design wind speed, Vult, for use in the design of Risk Category II buildings and structures shall be obtained from Figure 1609A. The ultimate design wind speed, Vult, for use in the design of Risk Categories III and IV buildings and structures shall be obtained from Figure 1609B. The ultimate design wind speed, Vult, for use in the design of Risk Category I buildings and structures shall be obtained from Figure 1609C. The ultimate design wind speeds for localities in special wind regions, near mountainous terrains, and near gorges shall be based on elevation. Areas at 4,000 feet in elevation or higher shall use 142 V mph (62.5 m/s) and areas under 4,000 feet in elevation shall use 116 V mph (51 m/s). Gorge areas shall be based on the highest recorded speed per locality or in accordance with local jurisdiction requirements determined in accordance with Section 26.5.1 of ASCE 7.

    In nonhurricane-prone regions, when the ultimate design wind speed, Vult, is estimated from regional climatic data, the ultimate design wind speed, Vult, shall be determined in accordance with Section 26.5.3 of ASCE 7.

    B. Add Section 1612.1.1 to the IBC to read:

    1612.1.1 Elevation of manufactured homes. New or replacement manufactured homes to be located in any flood hazard zone shall be placed in accordance with the applicable elevation requirements of this code.

    Exception: Manufactured homes installed on sites in an existing manufactured home park or subdivision shall be permitted to be placed so that the manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches (914 mm) above grade in lieu of being elevated at or above the base flood elevation provided no manufactured home at the same site has sustained flood damage exceeding 50% of the market value of the home before the damage occurred.

Historical Notes

Derived from Volume 22, Issue 03, eff. November 16, 2005; Errata, 22:5 VA.R. 734 November 14, 2005; amended, Virginia Register Volume 24, Issue 14, eff. May 1, 2008; Volume 30, Issue 16, eff. July 14, 2014.

Statutory Authority

§ 36-98 of the Code of Virginia.