A garage can hold more than cars. Around Griffin, owners add apartments over new garages for family, build a bonus room over an existing one, or turn a bay into a bedroom. Each of these turns the garage into living space, so zoning, the foundation and the building code all come into play.
Every dollar figure on this page is a national figure published by HomeGuide, not a quote from us. HomeGuide publishes no garage prices for Georgia or for Griffin, and the clay, slope, drive length and finish on your lot all move the real number. Figures read on homeguide.com in October 2026.
How much does a garage with an apartment above cost?
HomeGuide puts a garage with an apartment above at $200 to $350 per square foot, or $80,000 to $300,000 in total. A prefab garage with an apartment runs $60 to $100 per square foot, or $35,000 to $100,000, by the same page.
| Footprint | Square feet | National figure (HomeGuide) |
|---|---|---|
| 20 x 20 | 400 | $80,000 to $140,000 |
| 20 x 24 | 480 | $96,000 to $168,000 |
| 24 x 24 | 576 | $115,000 to $200,000 |
| 36 x 24 | 864 | $173,000 to $300,000 |
Can I build an ADU over or in my garage in Georgia?
Whether you can build an ADU (accessory dwelling unit) over or inside your garage is decided by your city or county zoning, not by one statewide rule we can point you to. Some south metro codes allow a guest house or accessory apartment, some limit who can live in it, and some do not allow a second dwelling at all. Subdivision covenants can be stricter still. HomeGuide puts an above-garage ADU at $120,000 to $300,000 for a 600 square foot complete living unit. We check the zoning for your address before any plans are drawn.
Can I build a second story over my existing garage?
Often yes, a second story or bonus room can go over an existing garage if the walls and footings can carry it. HomeGuide puts a second-story addition over a garage at $60,000 to $200,000 or more, depending on features and finishes. In south metro subdivisions, a room above the garage is a common way to add space without using more of the lot.
Can my garage foundation hold a room on top?
Many garage foundations were not built to hold a room on top. A slab with thin edges was sized for one-story walls, so a second floor may need deeper footings or new piers under the walls. An engineer should check the foundation and the wall framing before you design upstairs space. If the footings fall short, they are reinforced or the garage is rebuilt.
How much does it cost to convert a garage into a bedroom or living space?
HomeGuide puts a garage conversion to living space at $50 to $200 per square foot, and a garage-to-bedroom conversion at $5,000 to $17,000. By size, it lists $5,000 to $20,000 or more for a one-car garage and $10,000 to $50,000 or more for a two-car. A full bathroom adds $20,000 to $30,000 or more on the same page.
Does converting a garage hurt resale value?
Converting a garage can hurt resale value where buyers expect to park inside. HomeGuide says a conversion in an area with limited parking options may devalue the property, and that some cities require a certain amount of covered parking. In a south metro subdivision where every neighbor has a garage, ask a local agent before you give yours up. A permitted, well-finished room holds value better than a rough one.
Do I have to replace or raise the slab when converting a garage?
Usually the slab stays, but the floor on top of it changes. Garage slabs slope toward the door and sit below the house floor, so the new room gets a raised floor on sleepers or a leveling layer over a vapor barrier. A badly cracked or sunken slab is the exception and may need replacing. The old door opening gets a short wall on a footing or curb.
Can I rent out an apartment above my garage?
Renting out a garage apartment depends on your city or county zoning and, in a subdivision, on the HOA covenants. Some local rules allow it, some limit the unit to family or guests, and some forbid a second rental unit on a single-family lot. We have not found one Georgia rule that answers this for every town, so ask your planning office before you build for rent.
What does the code require for a garage turned into a bedroom?
A bedroom in a converted garage must meet the same residential code as any bedroom: an emergency escape window, smoke alarms, enough ceiling height, heat, and proper light and ventilation. If part of the garage stays a garage, the wall between it and the room is a fire separation with gypsum board on the garage side, and no door may open from the garage directly into a sleeping room.
How do I keep a room over a garage cool in a Georgia summer?
Insulate the roof, walls and the floor over the open bay, then condition the room on its own. A ductless mini split is the usual choice; HomeGuide's garage conversion page puts one zone at $2,500 to $6,000. Good attic venting helps too, because the space under a garage roof gets very hot by July.
Want a price for your own lot? We come out, look at the ground, the drive and where the garage can go, then put the size, materials and price in a written quote. Call or text (678) 661-6646.