Effingham County, GA Accessory Structures: Garage Conversions (2026)

Section 3.46.10 of the Effingham County Zoning Ordinance, part of the county's 2025-2026 accessory dwelling unit framework, allows an existing accessory structure such as a detached garage to become an ADU through conversion rather than new construction. Four conditions must all be met. First, the structure has to be brought into full compliance with the current building code's requirements for habitable space, meaning the conversion cannot simply wall off part of a garage; it must meet the same livability standards as new construction. Second, the converted unit still has to satisfy the ADU size and livable-space standards set for the district under §§ 3.46.4 or 3.46.5, so a large garage cannot be converted wholesale if it would exceed the 75-percent-of-the-main-home or 1,200/1,000-square-foot caps.

Third, the conversion cannot increase any nonconformity the structure already has, which matters for garages that predate current setback or coverage rules and were only legal because they were grandfathered. Fourth, the owner must verify adequate water, sewer, or septic capacity for the combined load of both the ADU and the principal dwelling, which under § 3.46.6 can require Effingham County Health Department certification when a septic system serves both units. Like any other ADU, a converted garage needs an administrative zoning permit and building permits under § 3.46.12 before it can be occupied, and enforcement follows § 3.46.13.