2021 SC BUILDING CODE · ASCE 7-10 / 7-16
South Carolina Wind Load Requirements
From the 187-mile Atlantic coast to the Upstate — design wind speeds, adopted codes, and county wind maps in one centered reference.
ADOPTED CODE · STANDARD
The Code South Carolina Enforces
The 2021 SC Building Code (based on the 2015 IBC) governs every structure; jurisdictions reference ASCE 7-10 or ASCE 7-16 by local adoption.
2021 SC Building Code
Based on the 2015 International Building Code with state amendments.
2015 IBC BASEASCE 7-10 / 7-16
Referenced jurisdiction by jurisdiction depending on local adoption timelines.
JURISDICTION-SPECIFICAuthority Having Jurisdiction
Local building departments and counties enforce and interpret the code.
LOCAL AHJPE Certification
An SC-licensed Professional Engineer seals plans in coastal high-wind areas.
COASTAL SEALWIND ZONES · COAST TO UPSTATE
Design Wind Speed by Region
Atlantic hurricane exposure drives coastal speeds high; values step down with distance inland to the Upstate.
Immediate Coastal (0–5 mi)
Barrier islands and low-lying shoreline take the full Atlantic exposure.
130–150 MPHCoastal Counties (5–20 mi)
Inland of the immediate shore but still hurricane-influenced.
110–130 MPHMidlands Region
Central counties where wind speeds moderate well below the coast.
90–110 MPHUpstate Region
The lowest design speeds in the state, far from Atlantic exposure.
85–100 MPHMany coastal counties adopt county-specific wind maps that may prescribe higher design speeds than ASCE 7 minimums. Always verify the local jurisdiction before designing.
COUNTY WIND MAPS
Coastal Counties & Their Wind Speeds
Four coastal counties carry the state's highest design speeds, each with county-specific provisions.
Charleston County
Charleston, Mount Pleasant, Isle of Palms, Folly Beach, Sullivan's Island.
130–150 MPHHorry County
Myrtle Beach, North Myrtle Beach, Surfside Beach, Garden City.
130–150 MPHBeaufort County
Hilton Head Island, Beaufort, Bluffton, Fripp Island sea-island geography.
130–150 MPHGeorgetown County
Georgetown, Pawleys Island, Litchfield Beach, Murrells Inlet marsh exposure.
130–150 MPHCITY GUIDES
South Carolina City Wind Load Guides
Drill into city-specific codes and design speeds for the state's busiest coastal markets.
DESIGN REQUIREMENTS
What Coastal Projects Must Address
Hurricane winds drive envelope, debris, and load-path requirements across the coastal counties.
Components & Cladding
Windows, doors, roofing, and siding rated for positive and negative pressures; corners and edges see the highest GCp.
GCp ZONESWind-Borne Debris
Counties at 130+ mph require impact glazing, rated assemblies, or approved shutters on all openings.
130+ MPH ZONESContinuous Load Path
Roof-to-wall straps, anchored sills, and proper sheathing carry uplift from roof to foundation.
UPLIFT PATHWind Mitigation
Straps, enhanced deck attachment, opening protection, and hip roofs can earn coastal insurance discounts.
INSURANCE CREDITRISK CATEGORIES · ASCE 7
Risk Category Sets the Speed Map
A higher risk category points to a longer return-period wind map — higher design speed, higher loads. PE seal is required for coastal high-wind structures.
Category I
Low-hazard: minor agricultural and storage structures (300-year map).
300-YR MRICategory II
Standard occupancy: homes, offices, and most buildings (700-year map).
700-YR MRICategory III
Substantial hazard: large assembly and schools (1,700-year map).
1,700-YR MRICategory IV
Essential facilities: hospitals, fire, police, and EOCs (3,000-year map).
3,000-YR MRIRUN THE NUMBERS
Calculate South Carolina Wind Loads Instantly
Coastal 150-mph speeds for Charleston, Beaufort, and Horry pre-applied — with 2021 SC Building Code references and wind-borne debris flags in every report.