TEXAS · BEXAR COUNTY
Where the Hill Country Meets the City: San Antonio Wind Load Requirements
South-central Texas, perched at the Balcones Escarpment edge of the Hill Country — design speeds driven by inland thunderstorms and weakened Gulf systems, not coastal landfall.
ASCE 7-22 · WHY THESE NUMBERS
An Inland Hazard, Not a Coastal One
Roughly 150 miles from the Gulf, San Antonio rarely sees an intact hurricane — its loads come from severe spring storms and the lift of the escarpment.
Weakened Gulf Systems
Tropical storms reach Bexar County drained of strength — rain and gusts, not sustained landfall winds.
INLAND ~150 MIConvective Downbursts
Spring squall lines, derechos and microbursts produce sharp, shifting straight-line winds across central Texas.
PEAK SPRINGBalcones Escarpment Lift
Ridges and bluffs west and north of the city speed up flow — Kzt analysis (Sec. 26.8) matters on exposed crests.
Kzt > 1.0 ON CRESTSExposure B vs C across Bexar County
Built-up San Antonio inside Loop 410 and Loop 1604 typically reads Exposure B. Open ranch land, grasslands and undeveloped Hill Country sites to the west and north read Exposure C, often paired with a topographic factor on hilltops and along the escarpment edge.
ASCE 7-22 TABLE 1.5-1 · RETURN PERIODS
Risk Category Picks the Speed Map
There is no importance-factor multiplier — a higher risk category simply reads V from a longer-return-period map, so the design speed climbs above the 105–115 mph Risk II baseline.
| Risk Category | Return Period (MRI) | Typical San Antonio Use |
|---|---|---|
| I | 300-year map (lowest) | Minor ag & storage structures |
| II | 700-year map (baseline) | Homes, retail, most occupancies |
| III | 1,700-year map | Schools, assembly >300 |
| IV | 3,000-year map (highest) | Hospitals, fire/EOC, shelters |
PERMIT CHECKLIST · BEXAR COUNTY
What a San Antonio Submittal Must Carry
Six pieces every wind-load package needs before Development Services or the County will sign off.
Correct Basic Wind Speed
105–115 mph (Risk II), read by exact site — never a coastal value.
VARIES BY SITEExposure Determination
B for urban fabric, C for open Hill Country — per Sec. 26.7.
B / CTopographic Factor
Kzt check for ridges, bluffs and the Balcones Escarpment (Sec. 26.8).
KztIBC + TX Amendments
City and County adopt the IBC referencing ASCE 7-22 for wind.
ASCE 7-22C&C + MWFRS Pressures
Shifting storm winds make cladding & component design critical.
BOTH SYSTEMSTexas PE Seal
Commercial & complex structures need a Texas-licensed PE seal.
WHERE REQUIREDCENTRAL TEXAS · STATEWIDE
Compare Across Texas
San Antonio mirrors its Hill Country neighbor Austin, and sits well below the Gulf-coast cities to the south and east.
Austin
Twin Hill Country profile, just up I-35.
CITYHouston
Higher loads from inland hurricane reach.
CITYDallas
North Texas thunderstorm & tornado driven.
CITYAll of Texas
Statewide adoption & map overview.
STATEOfficial Bexar County resources
San Antonio Development Services · Bexar County Building Inspections · Texas PE Licensing Board
RUN THE NUMBERS
Get a Site-Exact San Antonio Wind Load Report
Enter any Bexar County address — the calculator applies the right 105–115 mph map value, exposure, topographic factor and ASCE 7-22 pressures, then builds a PE-ready report.