Garage conversions to living space on the North Carolina coast

From the address alone, we can find your town's rule for a garage with a kitchen and for one without. Whether the garage is attached to the house decides which rule applies.

An apartment, with a kitchen of its own

Most town codes that define a second home draw the line at cooking. A kitchen, a bath and a place to sleep make the garage an accessory dwelling under your town's rule. Several towns want it to have its own outside door, and the building code gives every home one. The door between the garage and the house can stay as an inside door, where the inspections office that issues your permit allows it.

A bedroom, office or gym, with no kitchen

A garage room with no kitchen stays part of your home. It is built and permitted as an alteration, outside any ADU rule, and the building code still reaches it, from insulation to alarms. A garage that stands apart also meets the town's rules for accessory buildings. On septic, a new bedroom adds to what the system carries, and the septic rules count any room the building code calls a sleeping room.

Attached, or standing apart

Is your garage attached to the house, or does it stand on its own? Under the building code, the State Fire Marshal's office reads an attached garage as part of the house. So a kitchen there makes a home inside the house. A kitchen in a garage that stands apart makes a detached one. Several towns allow only one of the two.

What the garage gives up

The wide door and the sloped floor go first, and the parking goes too, unless one bay stays a garage. A bay that still holds the riding mower or the golf cart counts as a garage, whatever you call it. It keeps the garage rules.

You make these calls.

• A kitchen, or a room with none
• The whole garage, or one bay
• A bath, and where its drains run
• The number of bedrooms, which sets the load on a septic system
• Windows or a door in the old door opening
• The house's heating and cooling, or a system of its own
• Where the water heater and furnace go

A new garage to replace the one you convert is a renovation addition.

Weighing the other kinds? If the garage can carry a second floor, a garage apartment goes on top and the cars keep their space. With room behind the house, a detached ADU can stand on its own. An in-law suite is built onto the house or made inside it. The ADU page sets the four kinds next to each other.

Towns with a rule for a home inside the house

Southport, Leland, Shallotte, Winnabow and Burgaw each name a unit inside the house, and most cap its size. So does Surf City, on mainland lots. Southport, and Burgaw in four of its districts, hold a hearing first. Atkinson lists one in town with no written terms. Boiling Spring Lakes decides whether a converted garage qualifies. Carolina Beach names an apartment only inside an existing structure.

Wilmington lets a garage become an ADU by conversion, attached or standing apart, in the districts that allow one. It can reach half the house's floor area or 1,200 square feet, whichever is less. A Wilmington lot still in a legacy district, such as R-20, follows the rules in force before December 2021.

Towns that name only a detached home

New Hanover County's ADU is detached by definition, and a detached garage can become one by right where the district lists it. One built before January 3, 2023 can convert even where its size or placement misses the county's standards. That covers Masonboro, Ogden, Porters Neck, Castle Hayne and Myrtle Grove. Pender County writes its rule for a detached unit too, up to 33 percent of the house's heated floor area. That covers Hampstead, Rocky Point, Maple Hill and Currie. Scotts Hill follows whichever county its parcel sits in.

In both counties, a kitchen in an attached garage has no ADU path, and the county's planning office decides how it reads. The path both counties name is a detached ADU, such as a garage that stands apart.

St. James wants the unit behind the house and at least 10 feet from it, by special use permit. As written, only a detached garage can qualify. Calabash allows a detached garage apartment in residential districts, on the town's terms. For any other form, the town decides.

Where the beach codes draw the line

Wrightsville Beach allows no living space in an accessory building, so a detached garage there stays a garage. In Carolina Beach, a detached accessory building may not be used as a dwelling unit, and it holds three plumbing fixtures at most. Sunset Beach and Topsail Beach name an accessory dwelling only in business districts. Oak Island names only a garage apartment, as a special use in R-6MF.

A garage with no kitchen

Turned into a bedroom, office or gym, an attached garage is a room of the house in every town on the table. It takes a building permit. A detached garage is where towns differ, as the beach towns above show.

Where the cars go

Where will the cars park once the garage is a room? Where the garage holds the house's required parking, towns such as Carolina Beach and Ocean Isle Beach still require that minimum. Most towns that allow a second home want a parking space for it. Holden Beach, Kure Beach and Carolina Beach count a house's parking by bedrooms, Oak Island by rooms and Wrightsville Beach by toilets. There, the new room can raise the count, and the town confirms it.

Where the code names no ADU

Ocean Isle Beach, Holden Beach, Caswell Beach and Kure Beach write no ADU into their codes. A kitchen in the garage there is a question the town's own office answers for the lot. That's the planning office in Ocean Isle Beach and Planning and Inspections in Holden Beach. In Caswell Beach it's the zoning administrator, and in Kure Beach the Building Inspector. The ADU town table gives every town's rule in one place.

Code in force

2018 North Carolina Residential Code. New work meets the rules for a new structure (Section R102.7.1).

Permit

Required: the job changes the structure and adds wiring, plumbing or heating (General Statute 160D-1110).

Energy

On a job over $10,000, 10 percent of the project cost goes to energy features you choose, and opened cavities are insulated (Section N1109.2).

A bedroom

An escape opening, a 7-foot ceiling and smoke alarms placed as in a new house (Sections R310.1, R305.1 and R314.2.2).

A garage bay that stays

Gypsum board on its side of the shared wall, and no door into a bedroom (Sections R302.5.1 and R302.6).

Your garage was left out of the energy code.

State law exempts garages from the energy code, so yours was built without it. Once the room is heated and cooled, the rule for newly conditioned space applies. On a job over $10,000, 10 percent of the project cost goes toward energy features you choose. Cavities opened during the work get insulated, and new walls, windows and doors meet the energy chapter. The parts you leave alone need no upgrade.

A room that feels like the house asks for more than the code's share: a tight shell and fresh air brought in on purpose. Why small spaces are harder and airtightness without stuffy interiors cover both.

The door opening becomes a wall.

The new wall in the old door opening carries weight like any outside wall. It needs a footing or slab edge that can take it. We check what's under it before we frame. The slab edge carries the wall as it stands, or it needs work below first. The wall is braced and sheathed to the code's bracing rules. Its new windows and door are rated for the same wind as the house.

The floor slopes toward the old door.

A garage slab is poured to slope toward the door or a drain, so spills run out. The code asks for no moisture barrier under a garage slab, so yours may have none. So the new floor is built up over the slab, level and set to meet the house.

A bedroom needs a way out and alarms.

Every bedroom gets an escape window or door to the outside. Living space gets light, fresh air and a ceiling at least 7 feet high. Permitted work brings smoke alarms up to new-house placement. Carbon monoxide alarms follow where the house has a fuel-fired appliance, a fireplace, or a garage that opens into it.

Heating and cooling are sized to the room.

The new room's heating and cooling is sized to a load calculation, on the house's system or one of its own. Sizing equipment to the load explains why. A water heater or furnace in the garage was installed to the garage rules, and the code limits gas appliances in a bedroom or bath. So a gas furnace or water heater that ends up in a bedroom or bath may have to move, or change to a direct-vent model.

A kitchen brings drains, and a second home.

A kitchen or a bath means drains cut into the slab, under a plumbing permit. A kitchen in an attached garage also puts a second home under the house's roof. The code separates two homes in one building with fire-rated walls and floors. The inspections office that issues your permit decides how your converted garage is classed, and so whether that separation applies.

A detached garage close to the house may need fire-rated walls facing it once it holds a home. On septic, the new bedrooms add to the design flow the system has to carry. Environmental Health, or an authorized private evaluator, approves that before work starts. One septic tank serving both homes is sized by all the bedrooms in both.

With a kitchen

A kitchen adds its drains and venting. The apartment also gets its own outside door, which the code asks of every home. On septic, the approval for the added bedrooms comes before work starts.

Without one

A room with no kitchen takes the same steps with fewer trades, and a bath only if you want one.

Our six-step process and the ADU process show how the whole job runs.