Fulton County, GA | 105-115 mph Design Wind Speed | Georgia Building Code (IBC) | Severe Thunderstorms & Tornadoes | Exposure B
Calculate Atlanta Wind Loads Now →Atlanta, located primarily in Fulton County, Georgia, has moderate wind load requirements that account for its inland location and exposure to severe thunderstorm systems and occasional tornadoes. Georgia has adopted the Georgia State Minimum Standard Codes which incorporates the International Building Code (IBC) with state-specific amendments. Design wind speeds for Risk Category II structures typically range from 105-115 mph (3-second gust) based on ASCE 7-22 wind speed maps.
These requirements exist because Atlanta experiences frequent severe weather including severe thunderstorms with damaging straight-line winds, occasional tornadoes, and remnants of tropical systems that track inland from the Gulf Coast and Atlantic Coast. The March 14, 2008 tornado that struck downtown Atlanta demonstrated the city's vulnerability to severe convective weather events, causing significant damage to high-rise buildings, CNN Center, and the Georgia Dome.
Design Wind Speed (Risk Category II): 105-115 mph (3-second gust, varies by location)
Design Wind Speed (Risk Category III): ~120-130 mph
Design Wind Speed (Risk Category IV): ~130-140 mph
Exposure Category: B (urban/suburban areas)
Building Code: Georgia State Minimum Standard Codes (adopts IBC)
Wind Load Standard: ASCE 7-22 (current edition)
County: Fulton County (primarily), DeKalb County, Cobb County
Weather Risks: Severe thunderstorms, tornadoes, tropical system remnants, straight-line winds
Atlanta's design wind speed of 105-115 mph for Risk Category II structures reflects the city's inland location and exposure to severe convective weather systems. While not subject to direct hurricane impacts like coastal Georgia, Atlanta wind speed requirements account for:
The March 14, 2008 downtown Atlanta tornado was particularly significant because it demonstrated that even inland metropolitan areas with dense urban development are vulnerable to tornado damage. The EF2 tornado damaged high-rise buildings, the CNN Center, Georgia Dome, and numerous commercial structures. More recently, severe thunderstorm derechos and tropical system remnants have produced widespread wind damage throughout the Atlanta metropolitan area.
Calculating wind loads for Atlanta projects requires following ASCE 7-22 methodology as adopted by the Georgia Building Code. The fundamental velocity pressure equation is:
qz = 0.00256 Kz Kzt Kd Ke V²
For Atlanta with V = 110 mph (typical central Atlanta) and standard conditions, the resulting pressures are moderate. An Atlanta project with:
Results in a velocity pressure of approximately qz = 22.4 psf—moderate compared to coastal hurricane zones but higher than many inland regions with less severe weather exposure.
For areas with significant topographic features (hills, ridges in the piedmont region), the topographic factor Kzt may exceed 1.0, requiring detailed topographic analysis per ASCE 7-22 Section 26.8.
Georgia has adopted the Georgia State Minimum Standard Codes which incorporate the International Building Code (IBC) with state-specific amendments. The Georgia Department of Community Affairs (DCA) administers the state building code.
Key Atlanta building code considerations:
You can access Atlanta building permits and requirements through the City of Atlanta Department of City Planning or Fulton County Building and Development.
Atlanta projects must be classified into Risk Categories per ASCE 7-22 Table 1.5-1. Higher risk categories require increased design wind speeds:
| Risk Category | Atlanta Design Wind Speed | Building Types |
|---|---|---|
| Risk Category I | ~100-105 mph | Agricultural facilities, temporary structures, minor storage |
| Risk Category II | 105-115 mph | Residential, commercial, most standard occupancies |
| Risk Category III | ~120-130 mph | Schools, assembly >300, substantial hazardous materials |
| Risk Category IV | ~130-140 mph | Hospitals, fire stations, emergency shelters, EOCs |
Most of Atlanta qualifies as Exposure Category B due to dense urban and suburban development:
Exposure Category B (Urban/Suburban): The vast majority of Atlanta qualifies as Exposure B due to extensive urban and suburban development with numerous buildings, mature tree canopy, and other obstructions. Exposure B assumes urban and suburban areas with buildings having heights generally less than 30 feet extending more than 800 feet upwind. This applies to downtown Atlanta, midtown, Buckhead, and virtually all established neighborhoods throughout the metro area.
Atlanta's Urban Forest: Atlanta is known as "the city in a forest" with extensive tree canopy coverage. This heavy vegetation combined with dense development firmly establishes Exposure B for the majority of the metropolitan area.
Engineering Judgment Required: In rare cases such as large cleared sites, airport areas, or major hilltops with exposed terrain, Exposure C may apply. Professional engineering judgment is required for unusual conditions.
Atlanta's wind load requirements are influenced by the city's exposure to severe thunderstorms and occasional tornadoes:
March 2008 Downtown Tornado: On March 14, 2008, an EF2 tornado struck downtown Atlanta during the SEC Men's Basketball Tournament, causing extensive damage to the Georgia Dome, CNN Center, Philips Arena, and numerous high-rise buildings. This event demonstrated that even dense urban cores are vulnerable to tornado damage. Window glass was shattered on high-rise buildings, roofing was torn from major structures, and the Georgia Dome's roof fabric was severely damaged.
Severe Thunderstorm Straight-Line Winds: Atlanta experiences frequent severe thunderstorms, particularly during spring and early summer. These storms produce damaging straight-line winds, large hail, and occasional tornadoes. Derecho events (organized lines of severe thunderstorms) can produce sustained high winds and widespread damage across the entire metropolitan area.
Tropical System Remnants: When hurricanes or tropical storms make landfall on the Gulf Coast or Atlantic Coast of Georgia, South Carolina, or Florida, the remnants often track inland through Georgia. While greatly weakened from landfall, these systems can still produce sustained winds of 40-60 mph and wind gusts exceeding 70 mph across the Atlanta area. Recent examples include remnants of Hurricane Michael (2018), Hurricane Irma (2017), and Hurricane Zeta (2020).
Atlanta zip codes span a large metropolitan area with relatively consistent wind speed requirements. Common Atlanta zip codes include:
The WindLoadCalc.com wind load calculator automatically applies the appropriate Atlanta wind speed based on your specific zip code or street address, accounting for local terrain conditions and exposure.
Wind load calculations for Atlanta building permits have varying PE requirements depending on building type and complexity:
Georgia Professional Engineers must be licensed through the Georgia State Board of Professional Engineers and Land Surveyors.
Engineers, architects, and contractors should reference these official resources for Atlanta wind load compliance:
The wind load calculator at WindLoadCalc.com automatically applies all Atlanta-specific requirements:
WindLoadCalc.com automatically handles all Atlanta-specific requirements including the 105-115 mph design velocity, Exposure Category B assignment, Risk Category adjustments, and component pressure coefficients. Simply enter your Atlanta project address or zip code for instant, accurate calculations.
Calculate Atlanta Wind Loads Now →Atlanta's wind load requirements differ significantly from coastal Georgia hurricane zones:
| Requirement | Atlanta (Inland) | Coastal Georgia |
|---|---|---|
| Design Wind Speed | 105-115 mph | 140-160 mph |
| Exposure Category | Primarily B (urban) | C or D required |
| Wind-Borne Debris | Not required | Impact protection required |
| Hurricane Impact Zone | Not applicable | Required compliance |
| Primary Risk | Severe thunderstorms, tornadoes, tropical remnants | Hurricanes, tropical storms |
While Atlanta does not face direct hurricane impacts, the city's severe thunderstorm and tornado risk, combined with exposure to tropical system remnants, requires rigorous wind load design appropriate for Georgia's inland severe weather environment.
Atlanta is the center of a large metropolitan area spanning multiple counties. Wind load requirements for the broader Atlanta metro region are generally consistent with Atlanta proper:
Engineers working across the Atlanta metropolitan area should verify specific wind speeds and exposure categories for each project location, though most of the region maintains consistent 105-115 mph design velocities and Exposure B conditions.
WindLoadCalc.com provides instant, accurate wind load calculations for Atlanta projects. Our software automatically handles the 105-115 mph velocity range, Exposure B determination, and generates PE-ready reports for building permit submission.
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