Wind Speed Maps

Wind speed lines have changed because of the improved science (i.e. computer simulations). The updated maps are based on a new and more complete analysis of hurricane characteristics performed over the past 10 years. The wind speed indicated for each wind speed line is different for the 2010 standard due to change in wind speed calculation philosophy. The new wind-borne debris regions (for opening protection) are areas within 1 mile of the coastal mean high water line where the ultimate design wind speed (Vult) is 130 or greater; or in areas where the ultimate design wind speed (Vult) is 140 or greater.

Risk Category

• Risk Category I (PDF)
  • Buildings and other structures that represent a low hazard to human life in the event of failure, including but not limited to:
    • Agricultural facilities
    • Certain temporary facilities
    • Minor storage facilities
    • Screen enclosures
  • Simple Terms: Utility, Residential Storage Buildings, Agricultural Structures
• Risk Category II (PDF)
  • Buildings and other structures except those listed in Risk Categories I, III, and IV.
  • Simple Terms: Single Family
• Risk Category III (PDF)
  • Buildings and other structures that represent a substantial hazard to human life in the event of failure, including but not limited to:
    • Buildings and other structures whose primary occupancy is public assembly with an occupancy load greater than 300
    • Buildings and other structures containing elementary school, secondary school or day care facilities with an occupant load greater than 250
    • Buildings and other structures containing adult education facilities, such as colleges and universities, with an occupant load greater than 500
    • Group I-2 occupancies with an occupant load of 50 or more resident patients but not having surgery or emergency treatment facilities
    • Group I-3 occupancies
    • Any other occupancy with an occupant load greater than 5,000
    • Power-generating stations, water treatment facilities for potable water, waste water treatment facilities and other public utility facilities not included in Risk Category IV
    • Buildings and other structures not included in Risk Category IV containing sufficient quantities of toxic or explosive substances to be dangerous to the public if released
  • Simple Terms: Structures with High Occupant load and Water Treatment Centers
• Risk Category IV (PDF)
  • Buildings and other structures designated as essential facilities, including but not limited to:
    • Group I-2 occupancies having surgery or emergency treatment facilities
    • Fire, rescue, ambulance and police stations and emergency shelters
    • Designated earthquake, hurricane or other emergency shelters
    • Designated emergency preparedness, communications and operations centers and other facilities required for emergency response
    • Power-generating stations and other public utility facilities required as emergency backup facilities for Risk Category IV structures
    • Structures containing highly toxic materials as defined by Section 307 where the quantity of the material exceeds the maximum allowable quantities of Table 307.1(2)
    • Aviation control towers, air traffic control centers and emergency aircraft hangers
    • Buildings and other structures having critical national defense functions
    • Water storage facilities and pump structures required to maintain water pressure for fire suppression
  • Simple Terms: Fire and Police Stations, Emergency Communication Facilities and Hospitals