Building permits, zoning and septic rules in Lexington County, South Carolina

Unincorporated Lexington County requires a building permit to construct, enlarge, renovate, move, or change the occupancy of a building or structure; regulated electrical, gas, mechanical, and plumbing work also requires the corresponding trade permits¹. Ordinary repairs, maintenance, and listed exempt work are exceptions, but installing or replacing a manufactured home requires a building permit regardless of cost¹. Lexington County applies the International Building Codes and state-adopted appendices in the version most recently adopted by SCLLR⁸.

Lexington County publishes building-permit and development-review fees; staff calculate building-permit fees from project valuation, subject to a $50 minimum⁹. A qualifying residential owner-builder may obtain a building permit for the owner's residence, but the home cannot be offered for sale or rent for two years and hired trades must be properly licensed when required¹. A qualifying farm structure has a limited state building-code exemption, but the owner must file an affidavit before construction and local authority to require a building permit remains¹⁰.

Lexington County's Building/Safety Inspection Division is the county building-permit contact at 212 South Lake Drive, Lexington, SC 29072; call (803) 785-8130 or email BuildingInspections@lexingtoncounty.sc.gov¹¹. County applicants use the online building-permits portal to apply, request inspections, and upload documents¹².

Town of Lexington, Cayce, and Town of Springdale handle their own building permits^13,14,15. Columbia, mainly in Richland County but extending into Lexington County, also handles its own building permits¹⁶. SCDES handles septic permits throughout Lexington County where public or community sewer is unavailable³. For county zoning applications, map amendments, and variances, contact the Zoning Division at (803) 785-8121 or CDCustomerService@lexingtoncounty.sc.gov^11,17.

Lexington County zoning applies only in unincorporated areas⁷. Town of Lexington, Cayce, Town of Springdale, Town of South Congaree, and Town of Chapin administer their own zoning^{13,18,19,20,21}. Columbia, mainly in Richland County but extending into Lexington County, has its own zoning; SCDES remains the septic-permit authority countywide^3,22.

County zoning maps show both district and street classification⁷. Residential accessory buildings need at least 5 feet from adjoining property lines, subject to buffering and other applicable setbacks². Qualifying residential uses adjoining an agricultural operation in the Agricultural District overlay require a 50-foot property-line setback⁵.

Residential Detached (Limited) developments prohibit secondary dwellings; each dwelling lot must be 4,000–5,000 square feet and at least 50 feet wide, dwelling coverage is capped at 50%, and height at 2 stories or 30 feet⁵. These are development-specific standards; waterfront and airport overlays impose separate height controls⁵.

SCDES issues septic permits and inspects onsite systems throughout Lexington County, including inside municipalities; county or municipal building permits and zoning approval are separate^3,23. For a home or manufactured home without public or community sewer, obtain SCDES approval and a Permit to Construct before seeking the building permit³. The application uses the D-1740 form and requires a plat or deed, a $150 fee, and submission through the state ePermitting portal³. The SCDES Columbia local office covers Lexington County; call (803) 896-0620²⁴.

SCDES inspects the installation and issues approval to operate when the system meets state standards²³. Before covering a new installation, the installer must schedule the septic inspection; if the inspector has not arrived within 30 minutes of the appointment, a licensed installer may self-inspect and submit the approved final-inspection form³. Only 18.2% of county soils are rated without severe limitations for a conventional drain field, so make the site evaluation an early purchase contingency²⁵.

A single RV used as a residence in unincorporated Lexington County follows Residential Detached standards, including density and setbacks, and must meet registration or licensing and vehicle parking/storage requirements⁴. Temporary RV housing is a separate accessory use with a primary residence, subject to buffering and other zoning conditions and an aggregate limit of 1 year⁵. During primary-home construction or after loss of an existing home, temporary occupancy follows the associated building permit and ends no later than 30 days after final inspection or permit expiration, whichever occurs first; that circumstance is exempt from density requirements⁵. Multiple habitation vehicles or rental use is classified as Transient Habitation and faces additional zoning rules²⁶.

Unincorporated Lexington County regulates a tiny home by form, zoning district, and street classification; a Residential Detached, Mobile Home, or Tiny Home lot generally needs at least 9,000 square feet, with a conditional exception for pre-existing nonconforming lots⁴. Mobile-home and tiny-home parks require Board of Zoning Appeals special-exception approval, a detailed site plan, and a zoning permit²⁷. We could not confirm a minimum habitable floor area; ask the Zoning Division to classify the unit and parcel¹¹.

1. Identify whether the parcel is unincorporated or inside a municipality, then get the zoning district, street classification, overlays, use approval, setbacks, and lot standards from the responsible zoning office^2,7.
2. Verify sewer availability; SCDES cannot issue an onsite-wastewater permit where public sewer is accessible²⁸.
3. If sewer is unavailable, submit the SCDES septic-permit application, plat or deed, and fee before seeking a building permit³.
4. For an individual residential well, submit the state Notice of Intent and $70 fee before construction²⁹.
5. Apply for the building permit through Lexington County's portal when the county is the building authority; inside a municipality, use its building-permit process^7,30.
6. Contact Floodplain Management about mapped flood risk and Public Works about a driveway permit for work in a county road right-of-way^31,32.
7. Request building inspections from the issuing building office, and schedule the SCDES septic installation inspection before covering the system^23,30.

Before dividing land in Lexington County, confirm subdivision review: each new parcel needs publicly maintained or approved private-road access, adequate storm drainage, water, and sewer; private-road access requires Planning Commission approval³³. Subdivision plats and land-development plans in unincorporated areas require county approval before recording³⁴. Check mapped flood risk with Floodplain Management and county-road encroachment questions with Public Works^31,32.

Installing or replacing a manufactured home requires a building permit regardless of cost¹. County zoning allows 2 mobile homes on a parcel, adjoining parcels, or parcels in the vicinity, or 3 if the owner lives in one; larger groupings are mobile-home parks requiring special-exception approval². Active agricultural operations in the Agricultural District overlay have specified noise and Neighborhood Appearance District exemptions, rather than a blanket exemption from county requirements⁵.

An unincorporated short-term rental requires a zoning permit and annual renewal, with occupancy limited to septic capacity^6,35. Lexington County's effective property-tax rate is about 0.5%, with a median annual bill of about $1,136²⁵.