Barndominium Builders in South Carolina

Barndominium builders in South Carolina have to plan for two very different states at once: the hilly red-clay country above the fall line and the flat, sandy, often wet Coastal Plain below it, with hurricane winds rising as you near the ocean. We build barndominium homes, kit packages, metal building homes, custom barndominiums and shop houses for landowners across the Midlands, the Pee Dee, the Grand Strand, the Lowcountry and the York and Lancaster area.

One statewide code, many local rules

South Carolina's Building Codes Council adopted the 2021 codes on October 6, 2021, and set January 1, 2023 as the date local jurisdictions had to begin enforcing them. The 2021 South Carolina Residential Code (the 2021 IRC with state modifications) is mandatory for every county and municipality, so a barndominium home gets permits and inspections whether it is in a city or out in an unincorporated county. The energy code is different: the 2009 IECC is set by state law (Act 143), not by the Council.

What changes from place to place is the paperwork and the design loads. Horry County, for example, asks for sealed engineering under the 2021 IRC, a wind design summary sheet, floor plans, elevations, two site plans and an energy sheet for a new house.

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Wind is the big design number

State rules tell builders to use the Council's published wind maps, and they let the local building official set the wind design category within that jurisdiction. The difference across the state is large. The Council's map lists all of York County at 115 mph. Goose Creek's design criteria call for 140+ mph. The City of Charleston designs to 150 mph. Steel frames, roof panels, doors and windows are all ordered for the number on your permit, and the code requires a continuous load path that carries uplift from the roof down to the foundation.

Septic comes before the building permit

On land without public sewer, the state's Department of Environmental Services has to approve and permit a septic system first; without it, the county will not issue a building permit. Clemson Extension's guide describes the steps: apply online with the plat or deed, pay the application fee, clear brush, stake the house footprint and wait in a first-come, first-served queue for the site evaluation. Above the fall line, a backhoe pit is required for that evaluation. We help you get the site ready so the evaluator can see what they need.

Heat, humidity and steel

Most of South Carolina is humid subtropical, with summer highs near 90 degrees and nights near 70. Charleston averages about 73 percent relative humidity across the year. Warm, wet air against cool steel is how condensation starts, so insulation, air sealing and HVAC sizing are part of our plan from the first sketch, not an afterthought.

What a project looks like

• Land visit and a check of soils, drainage and access
• County research: zoning, wind category, flood zone and septic path
• Floor plan and written, line-item estimate
• Septic permit, building permit and site prep
• Slab, shell erection and dry-in
• Insulation, mechanicals and interior finish-out

We build across the parts of South Carolina below and east of the Upstate, and each region asks for something different.

The Midlands and the fall line

Columbia sits right on the fall line, where the hilly Piedmont ends and the Coastal Plain begins. North and west, around Chapin, Newberry and Greenwood, the ground is Piedmont country: gently rolling to steep, with red clay subsoils like the Cecil series, which is kaolinite clay with mica under a sandy loam topsoil. That clay drains slowly, so we watch grading and where roof water goes. The Midlands also have the state's record heat, 113 degrees at USC Columbia in 2012, and freezing rain is more common than snow around and southeast of Columbia.

The Sandhills

A band of old wind-blown sand runs through the inner Coastal Plain, around Lexington, Camden, Aiken and North Augusta. Soils like the Blaney series carry about two feet of sand before reaching sandy clay. The sand drains fast and builds easily, but it needs care at slab edges and around downspouts so water does not wash it out.

The Pee Dee and the Coastal Plain

Around Florence, Darlington, Hartsville, Sumter and Orangeburg, the land flattens into the state's farm belt. Many Coastal Plain soils are poorly drained, with better ground on sandy ridges and slopes. South Carolina also has about 5,000 mapped Carolina bays: shallow, oval depressions that may hold a pond or swamp or sit dry. On flat, wet ground, house pad height and drainage matter as much as square footage.

The Grand Strand and the Lowcountry

From Conway and Loris through Georgetown, Charleston, Summerville, Walterboro, Beaufort and Bluffton, the land is nearly level flatwoods, marsh edges and sea islands. Wind design climbs here (Goose Creek uses 140+ mph and Charleston 150 mph), Charleston's frost depth is zero, and Goose Creek rates termite hazard as heavy. Flood maps decide a lot: in Horry County, a house in a flood plain needs a pre-construction elevation certificate, and VE zones have their own requirements.

York and Lancaster counties

Rock Hill, Fort Mill, York, Lancaster and Chester sit in the Piedmont near the North Carolina line. The state's map puts York County at 115 mph wind and seismic category B, lighter loads than the coast, with red clay ground that needs the same attention to drainage as the rest of the Piedmont.