OHIO · FRANKLIN COUNTY
Capital-City Wind Loads on the Central Ohio Plains
Columbus sits inland on flat glaciated terrain, far from Lake Erie's reach — a place where derechos and squall-line outflow, not coastal storms, set the design wind speed.
GEOGRAPHY OF THE GUST
What the Flat Interior Does to the Wind
Columbus lacks Cincinnati's river hills and Cleveland's lakefront fetch. The land is open, gently rolling, and unobstructed once a storm builds.
Unobstructed Inland Fetch
Glaciated, near-level ground lets straight-line winds run with few natural barriers once a storm matures.
FLAT TERRAINAir-Mass Crossroads
Gulf moisture meets dry continental air over central Ohio, firing severe convective storms from April through September.
CONVECTIVE SEASONDerecho Corridor
Long-lived squall-line windstorms can rake Franklin County with widespread damaging gusts across a single fast-moving front.
STRAIGHT-LINEDESIGN VALUE · ASCE 7-22
Reading 100–110 mph over the Capital
For Risk Category II buildings across Franklin County, the basic 3-second gust lands in the low triple digits — a moderate inland map, well below any coastal regime.
Velocity Pressure
qz = 0.00256 KzKztKdKeV² sets the baseline pressure on every surface.
ASCE EQ 26.10-1Exposure Coefficient
At 15 ft in urban Exposure B, Kz holds at 0.70 per Table 26.10-1.
Kz = 0.70Directionality & Terrain
Buildings carry Kd = 0.85; flat Columbus ground gives Kzt = 1.0 with no hill effect.
Kd 0.85 · Kzt 1.0Internal Pressure
Enclosed Columbus structures use GCpi = ±0.18 for the internal pressure term.
GCpi ±0.18Across higher Risk Categories the map you read V from changes — a longer return period, never a fixed importance multiplier.
| Risk Category | Map Return Period (MRI) | Franklin County Building Types |
|---|---|---|
| Risk Category I | 300-year map (lowest speeds) | Farm sheds on the county fringe, minor storage, temporary structures |
| Risk Category II | 700-year map — the 100–110 mph basis | Homes, retail, offices, most standard occupancies |
| Risk Category III | 1,700-year map (higher speeds) | Schools, assembly over 300, substantial-hazard facilities |
| Risk Category IV | 3,000-year map (highest speeds) | Hospitals, fire/police, emergency operations centers, shelters |
SURFACE ROUGHNESS · SECTION 26.7
Where the Capital Turns to Open Ground
Most of Columbus shelters behind continuous development, but the city's edges and its airport open into true Exposure C.
Exposure B — The Built City
Downtown, German Village, the Short North, Clintonville and Upper Arlington sit in continuous low-rise development qualifying as B.
URBAN / SUBURBANExposure C — The County Fringe
Open farm fields on the outskirts and the clear zones around John Glenn Columbus International Airport read as scattered-obstruction C.
OPEN TERRAINTransition Zones — Judgment Calls
Where Franklin County development meets rural land, the upwind roughness fetch decides the category — a call for the engineer of record.
SITE-SPECIFICPERMIT PATH · FRANKLIN COUNTY
Clearing the Columbus Plan Desk
Six checkpoints carry a Columbus wind-load package from velocity to a stamped, permit-ready report.
Adopt ASCE 7-22
The Ohio Building Code references the current edition — older ASCE tables get plan-review kickbacks.
CODE EDITIONFix the Risk Category
Capitol-Square government uses and OSU assembly buildings climb to a higher-speed map than standard retail.
TABLE 1.5-1Justify the Exposure
Document the upwind fetch so Exposure B is defensible — airport-adjacent and fringe sites may force C.
SECTION 26.7Split MWFRS and C&C
Run the frame and the cladding separately — roof panels, windows and siding take their own coefficients.
TWO LOAD PATHSSeal with an Ohio PE
Commercial, institutional and high-occupancy work needs calculations sealed by an Ohio-licensed Professional Engineer.
PE STAMPFile Through ePlan
Columbus Building Services takes wind-load submittals and tracking through its online ePlan portal.
SUBMITTALAUTHORITIES · OHIO & FRANKLIN COUNTY
Who Holds the Columbus Authority
Verify the locally adopted values and licensing with the offices that govern Franklin County construction.
Columbus Building Services
Permits, inspections and the ePlan portal for the City of Columbus.
PERMIT OFFICEOhio PE Licensing Board
Confirm active Ohio Professional Engineer licensure before a seal is applied.
PE LICENSINGOhio Building Code Division
The state Industrial Compliance authority behind OBC adoption and amendments.
STATE CODEACROSS OHIO
Compare Columbus to the Rest of Ohio
The capital reads lower and flatter than the lakefront cities — same code, different terrain story.
Cincinnati — River Hills
Hamilton County's Ohio River bluffs bring topographic terrain Columbus largely lacks.
NEARBY CITYWind Speed by Location
Pull the basic 3-second gust for any Ohio address against the ASCE 7-22 maps.
SPEED LOOKUPOhio Statewide Requirements
The OBC framework, edition adoption and amendments behind every Ohio jurisdiction.
STATE OVERVIEWRUN THE NUMBERS
Calculate Columbus Loads to the Last Coefficient
Enter a Franklin County address and get 100–110 mph applied, Exposure B or C resolved, Risk Category set, and a PE-ready report built for the Columbus plan desk.