Greenville SC room addition permit rules
Greenville Community Development requires a building permit and all applicable trade permits for room additions. Apply at greenvillesc.gov. SC contractor licensing required (llr.sc.gov). Licensed SC HVAC contractors, plumbers, and electricians for trade permits. Call (864) 467-4570 to confirm zoning setbacks and documentation requirements before engaging a designer. In Greenville's denser older neighbourhoods — particularly near downtown and the West End — rear yard setback constraints are a real first step, as many historic lots have limited rear yard dimensions that affect how much addition square footage is actually possible.
South Carolina's CZ3A energy code for new additions: wall insulation R-13–R-20, ceiling R-38–R-49, windows U-0.30 or better with SHGC of 0.30 or lower. The SHGC specification — limiting solar heat gain — is important for Greenville's significant cooling season. All footings must bear below Greenville's 6-inch frost line; in practice, 12–18 inch tube piers in concrete are standard and adequate for structural bearing.
The addition's foundation should match or interface properly with the existing home. For older crawl space homes, the addition can use a crawl space foundation that aligns with the existing — maintaining the accessibility advantage. For slab homes, a new slab pour for the addition footprint is standard. HVAC for the addition: a standard heat pump with variable-speed capability is the correct specification for CZ3A's mixed cooling/heating climate. Duke Energy for electric capacity (1-800-777-9898); Piedmont Natural Gas if gas heat is being extended (1-800-752-7504).
Three Greenville room addition scenarios
| Factor | What it means for your project |
|---|---|
| Zoning setbacks — confirm early | Dense historic neighbourhoods: limited rear yard. Confirm at (864) 467-4570 before design. |
| 6-inch frost depth | Footings 12–18 in. Much simpler than New England requirements. |
| CZ3A energy code | R-13–R-20 walls; R-38–49 ceiling; U-0.30/SHGC 0.30 windows. |
| Standard HP + variable-speed | No cold-climate spec needed. Variable-speed for CZ3A humidity. |
| Radon | SC has moderate radon in some areas. Test below-grade spaces before finishing. |
Phone: (864) 467-4570 | greenvillesc.gov
SC Contractor Licensing: llr.sc.gov
Duke Energy (electric): 1-800-777-9898 | Piedmont Natural Gas: 1-800-752-7504
Common questions about Greenville, SC room addition permits
What energy code applies to room additions in Greenville SC?
Greenville is in SC Building Code CZ3A. Room additions must meet: wall insulation R-13–R-20, ceiling R-38–R-49, windows U-0.30 or better with SHGC of 0.30 or lower. Verify current requirements with Community Development at (864) 467-4570.
What permits are needed for a room addition in Greenville SC?
Building permit plus applicable trade permits (HVAC, electrical, plumbing). SC contractor licensing required. Apply at greenvillesc.gov. Confirm zoning setbacks at (864) 467-4570 before design — Greenville's older neighbourhoods have limited rear yards.
Information based on Greenville, SC official sources and applicable state/local building codes as of April 2026. Codes and fees change — verify current requirements before starting work. For a project-specific report, use our permit research tool.