In-law suites and attached ADUs on the North Carolina coast
An in-law suite is a small home joined to your house, with its own front door, kitchen and bath. Some call it a mother-in-law suite or an attached ADU. We build them onto the house or make them inside it, where your town and your lot allow it. We work across Brunswick, New Hanover and Pender Counties, from our home base in Southport.
What you get with an in-law suite.
We find out what your town allows.
Each town draws its own line. Some allow a suite built onto the house. One names only a suite made inside the house. We look up your town's rule first.
Built onto the house, or made inside it.
An addition gets its own foundation, tied into your house's frame and roof. Or rooms you already have become a home of their own. We build both.
The wall between is planned early.
With its own kitchen, a suite can make your house two homes under the code. The wall and floor between them may then need to resist fire. We plan for that from the start.
Your in-law suite starts with the house you have.
An in-law suite is a home of its own, joined to yours, with its own entrance, kitchen and bath.
It can be built onto the house as an addition, or made from rooms already inside it. Your town's rule decides which it allows, and how big. We look that up for your address first.
Send the address. We'll check whether your town allows an in-law suite with its own kitchen, and how big.
A kitchen and its own door make it a second home.
Under the state's residential code, a dwelling unit is a complete, independent home. It has room to live, sleep, eat, cook and wash. Most town codes that define an ADU use the same test, and some add a separate entrance. So a kitchen is usually what brings in your town's ADU rule. Without one, the code sees more rooms in your house.
An addition, or rooms you already have.
Built on, the suite is an addition. It gets its own foundation and joins your house's frame and roof, so it needs room on the lot. Made inside, it takes rooms you already have, such as a wing at one end of the house. It adds no footprint, though it usually needs a new door to the outside.
Carolina Beach names only the second kind: an accessory apartment inside an existing structure. Wilmington names both. One is joined to the house by a roof and at least one wall. The other is an internal unit with its own outside entrance.
Where would yours go?
Which side of your house has room? A suite built onto the house has to fit inside the lot's setbacks. One made inside needs rooms you can give up and an outside wall for its own door. Burgaw puts any outside door of an attached suite on the side or rear of the house.
What you decide
- Built onto the house, or made inside it
- A shared wall, and whether a door joins the two homes
- The kitchen
- The bath
- How many bedrooms
Each choice brings a rule with it. The kitchen brings in your town's ADU rule. A door between the two homes is a question for the inspections office that issues your permit. Where it allows one, we can build it. On a septic system, each bedroom counts. A step-free entry and wider doorways are design choices you can make too.
When another kind fits better
A primary suite or a bonus room for your own household, with no kitchen and no separate entrance, is a renovation addition.
Is there no room beside the house, or does your town want the unit apart from it? A detached ADU stands on its own in the yard. If the rooms you would use are the garage, see garage conversion. Where a town names a unit over a garage, a garage apartment is the path. Our ADU page sets all four side by side.
Where an in-law suite is allowed, and how big
Some towns name a suite built onto the house or made inside it, and Carolina Beach names only the inside kind. New Hanover and Pender Counties write their ADU rule for a detached unit. Several beach towns name no ADU at all. Under the code, a suite with no kitchen is an addition or a remodel. Find your town below; the ADU page lists every kind.
| Town | County | What applies |
|---|---|---|
| SouthportBrunswick | Brunswick | A special use permit from the Board of Adjustment, in R-10, R-20 and four other districts. One per lot, inside the house or attached to it, up to 800 square feet. |
| Oak IslandBrunswick | Brunswick | The table of uses names no attached unit. Its one form is a garage apartment, a special use in the R-6MF district only. |
| St. JamesBrunswick | Brunswick | The Town Council decides a special use permit for R-20, R-15 and R-10 lots. The unit has to stand at least 10 feet from the house, so the code as written leaves no room for an attached suite. |
| Ocean Isle BeachBrunswick | Brunswick | The code names no ADU; the town decides lot by lot. |
| Holden BeachBrunswick | Brunswick | The code names no ADU; the town decides lot by lot. |
| Sunset BeachBrunswick | Brunswick | Residential lots have no accessory dwelling use. The code's only one sits above or behind a business, in its business districts. |
| Caswell BeachBrunswick | Brunswick | The code names no ADU; the town decides lot by lot. |
| LelandBrunswick | Brunswick | By right with zoning approval in R-20, R-15, R-6 and PUD, within or added to the house, with its own entrance. Up to 35 percent of the house's floor area or 800 square feet, whichever is less, plus one added parking space. |
| ShallotteBrunswick | Brunswick | Allowed by right in every residential district, one per property. Attached or inside the house, it can reach 35 percent of the house's floor area. It gets its own parking space, or two over 750 square feet. |
| CalabashBrunswick | Brunswick | In residential districts, the code allows a garage apartment detached from the house, on the town's terms. For any other form, such as a suite joined to the house, the town decides. |
| WinnabowBrunswick | Brunswick | County staff approve one per lot in the residential districts, with no hearing. The county's rule names an accessory apartment inside the main house. |
| Boiling Spring LakesBrunswick | Brunswick | By right with standards in R-1 through R-6 and PRD, one per lot, up to half the house's floor area. The code never says whether the unit can be attached, so the city decides. |
| WilmingtonNew Hanover | New Hanover | Allowed with conditions in most residential districts, built on with a shared roof and wall, or inside the house with its own outside entrance. Up to half the house's floor area or 1,200 square feet, whichever is less. |
| Wrightsville BeachNew Hanover | New Hanover | The code names no ADU; the town decides lot by lot. A duplex is a listed use in R-2 only. |
| Carolina BeachNew Hanover | New Hanover | The code's one form is an accessory apartment inside an existing structure: the suite made inside the house. Whether an addition to the house can hold one is the town's call. |
| Kure BeachNew Hanover | New Hanover | The code names no ADU; the town decides lot by lot. |
| MasonboroNew Hanover | New Hanover | The county's ADU is detached by definition, so an attached suite with a kitchen has no ADU path there. A parcel inside Wilmington's limits follows the city's rule. |
| OgdenNew Hanover | New Hanover | The county's rule covers a detached unit only, so a suite joined to the house has no ADU path. A detached unit up to 1,200 square feet is allowed by right in R-20, R-15, R-10 and the county's other listed districts. |
| Porters NeckNew Hanover | New Hanover | The county's ADU stands apart from the house, so an attached suite has no ADU path there. Inside the gates, the covenant is a second question. |
| Castle HayneNew Hanover | New Hanover | The county names only a detached ADU, by right in RA and its other listed districts. An attached suite with a kitchen has no ADU path, and Airport Residential (AR) parcels have no ADU path at all. |
| Myrtle GroveNew Hanover | New Hanover | The county's definition requires the unit to stand apart from the house, and it counts mother-in-law suites as ADUs. A detached unit is allowed by right in RA, R-20, R-15, R-10, R-7, R-5 and other listed districts; AR and R-20S allow none. |
| HampsteadPender | Pender | Pender County's rule covers a detached unit only, up to 33 percent of the house's heated floor area. A suite joined to the house has no ADU path, and the county's planning office decides how one reads. |
| Surf CityPender | Pender | Mainland lots only, one each; island lots get none. A unit within the house is allowed, smaller than the house, with one added parking space. |
| Topsail BeachPender | Pender | The code allows a unit inside a main building only in the B-1 and B-2 business districts. The residential districts, R-1 through R-4, list none. |
| Scotts HillPender | Pender | Your side of the county line decides, and both counties write their ADU rule for a detached unit. On either side, a suite joined to the house has no ADU path, and the county planning office decides how one reads. |
| BurgawPender | Pender | Mother-in-law suites count as accessory apartments: by right in RA, R-20 and B-1, by minor special use permit in four other districts. Up to half the house's size or 800 square feet, whichever is less, with any outside door on the side or rear. |
| Rocky PointPender | Pender | Pender County names a detached unit only. A suite joined to the house has no ADU path, and the county's planning office decides how one reads. The county's path is a detached unit up to 33 percent of the house's heated floor area. |
| Maple HillPender | Pender | The county's ADU is a detached unit, allowed in RA, RP, RM and PD; the MH district has none. A suite joined to the house has no ADU path there, and the county's planning office decides how one reads. |
| AtkinsonPender | Pender | In town, an accessory apartment is a permitted use in R-12 and B-1, with no written standards; the town confirms how a suite fits. Outside town, Pender County names only a detached unit. |
| CurriePender | Pender | Pender County's rule covers one detached unit, in the side or rear yard, up to 33 percent of the house's heated floor area. A suite joined to the house has no ADU path, and the county's planning office decides how one reads. |
Several towns allow both kinds.
Leland, Shallotte, Burgaw and Southport each name a unit added to the house or made inside it. Each caps its size, and Southport holds a hearing first. Wilmington names both kinds too. A Wilmington lot still in a legacy district, such as R-20, follows the rules in force before December 2021. Surf City allows one within the house on mainland lots. Around Winnabow, Brunswick County staff approve one inside the main house.
Carolina Beach names only the inside kind.
Carolina Beach names one form: an accessory apartment inside an existing structure. That is the suite made from rooms you already have. Whether an addition to the house can hold one is the town's call. Topsail Beach allows a unit inside a main building only in its two business districts.
New Hanover and Pender Counties name a detached unit.
New Hanover County's definition says the unit is detached from the house, and it counts mother-in-law suites as ADUs. Pender County writes its rule for a detached unit only. In both, an attached suite with a kitchen has no ADU path, and the county planning office decides how one reads. Around Masonboro or Rocky Point, the kind the county names is a detached ADU.
Some rules point away from an attached suite.
St. James asks for the unit to stand at least 10 feet from the house, so its rule leaves out an attached suite as written. Calabash allows a detached garage apartment in its residential districts. For an attached suite, the town decides. Oak Island's table names a garage apartment and no attached unit. Sunset Beach allows an accessory dwelling only above or behind a business. Boiling Spring Lakes never says whether its unit can be attached, so the city decides.
Where the code names no ADU
Holden Beach, Caswell Beach, Ocean Isle Beach, Wrightsville Beach and Kure Beach name no ADU of any kind. There the town office takes a suite with a kitchen one lot at a time. Holden Beach sends it to Planning and Inspections, and Caswell Beach to its zoning administrator. Ocean Isle Beach sends it to its planning office, and Kure Beach to its Building Inspector. Each code lists a two-family dwelling in at least one district, and the office decides whether a suite makes a house one.
With its own kitchen, your house holds two homes.
A suite with its own kitchen, bath and sleeping space is a dwelling unit under the state's residential code. The code calls a building with two of them a two-family dwelling. The inspections office that issues your permit decides whether your house is one. New work meets the rules for a new house, and the rest may stay as it was built (Section R102.7.1).
- Code in force
- 2018 North Carolina Residential Code. A suite with a kitchen, a bath and a place to sleep is a dwelling unit under it (Section R202).
- Between the two homes
- Two-family dwellings get walls and floors that resist fire for an hour (Section R302.3). The inspections office that issues your permit decides whether a suite makes your house one.
- Its own door
- At least one door to the outdoors for each dwelling unit (Section R311.2). The way out never runs through a garage (Section R311.1).
Your inspections office decides what the wall between needs.
In a two-family dwelling, the walls and floors between the homes resist fire for an hour. They run tight to the outside walls. As a rule, the wall runs from the foundation to the underside of the roof. The inspections office that issues your permit decides whether that rule reaches your suite, and we build to its answer.
The two-family section names no door between the homes. Whether you can have one, and what kind, is that office's call too. Where it allows one, we can build it.
Each home has its own way out.
Every dwelling unit gets at least one door to the outdoors. So the suite gets a front door of its own, and its way out never runs through a garage. Every bedroom also gets an escape opening: a window or door, big enough to climb through, that opens to the outside.
Smoke and CO alarms come with the work.
The suite gets smoke alarms placed as in a new home: in each bedroom, outside the sleeping area and on each level. Where permitted work reaches the main house, its alarms move to the same placement. Carbon monoxide alarms follow a fuel-fired appliance, a fireplace or an attached garage that opens into the home.
Energy rules follow the kind of suite.
An addition's new walls, roof and windows meet the energy rules for new construction. A suite made from rooms already heated and cooled meets them wherever the work changes something. If the house's ducts will reach an addition, the code asks for the house's system to be checked for the new design.
Heating and cooling can come from the house's system or a unit of the suite's own, sized for a small space. Why small is harder and right-sized equipment cover the sizing. Airtightness without stuffy interiors covers fresh air in a tight space.
On septic, bedrooms count.
Is your house on septic? State rules size a suite's flow by its bedrooms, whether it sits in the house or apart from it. The count is bedrooms, so a kitchen adds no flow. The tank is sized for the house and the suite together. Adding bedrooms takes approval from the county's Environmental Health office, or an authorized private evaluator, before work starts.
A historic district reviews the outside.
In a local historic district, an addition and a new front door are outside work. Each needs a certificate of appropriateness before work starts. Under state law, the commission has no say over the rooms inside, unless the house is a landmark whose owner agreed to interior review. Southport and Wilmington both have local historic districts.
We start where the suite meets the house.
Every in-law suite has a seam where it meets your house. Built on, the seam is the foundation, the frame and the roof. Made inside, it is the wall between the two homes and the new door out. The work starts there.
Built onto the house
Foundation beside the house
Footings and a foundation go in for the new rooms, set to meet the house's own.
Walls joined to the house
New walls go up and tie into the house's frame.
Roof tied in
The new roof joins the old one, flashed where they meet to keep the weather out.
The wall between
The wall and any floor between the two homes are built to what the inspections office that issues your permit requires.
Water, drains and power
Supply lines, drains, vents and circuits run to the new kitchen and bath. The pipes are tested before the walls close.
Insulation and finishes
Insulation, drywall, cabinets and fixtures go in once the work behind the walls passes inspection.
Made inside the house
Walls between the homes
New walls close the suite off, built to what the inspections office that issues your permit requires between two homes.
A door of its own
An outside wall is opened and framed for the suite's front door.
The kitchen's drains and vents
Drains and vents for the new kitchen and bath run through floors and walls already built.
Wiring and alarms
New circuits and alarms go in, wired together where the code asks.
Finishes
Drywall, cabinets and fixtures go in once the work behind the walls passes inspection.
Design and permits run first, through our six steps. The ADU process shows how they apply to a second home.
Questions about in-law suites
- What turns an in-law suite into an ADU?
- A kitchen, mostly. The state's residential code calls a complete home, with room to live, sleep, eat, cook and wash, a dwelling unit. Most town codes that define an ADU turn on cooking too. Leland and New Hanover County also name a separate entrance. Without a kitchen, the suite stays part of your house under the code.
- Can I build an in-law suite onto my house in New Hanover County?
- Outside the towns, the county's ADU is detached by definition. The definition says the unit is detached from the house, and it counts mother-in-law suites as ADUs. So an attached suite with a kitchen has no ADU path, and the county's planning office decides how one reads. The path the county names is a detached unit, up to 1,200 square feet, by right in most residential districts. Wilmington and the beach towns write their own rules.
- How big can an attached ADU be?
- Each town sets its own cap. Leland allows 35 percent of the house's floor area or 800 square feet, whichever is less. Shallotte allows 35 percent of the house's floor area. Burgaw allows half the house or 800 square feet, whichever is less, and Southport allows 800 square feet. Wilmington allows half the house's floor area or 1,200 square feet, whichever is less. Carolina Beach's code sets no size.
- Does an in-law suite need its own entrance?
- With its own kitchen, yes. The code gives each dwelling unit at least one door to the outdoors, and the way out never runs through a garage. Leland's rule names a separate entrance, and Burgaw puts any outside door on the side or rear. A door between the suite and the house is a question for the inspections office that issues your permit.
- Does an in-law suite need a fire wall?
- It may. The code gives a two-family dwelling walls and floors between the homes that resist fire for an hour. As a rule, the wall runs from the foundation to the underside of the roof. The inspections office that issues your permit decides whether your suite makes the house a two-family dwelling. We plan the suite around its answer, so the wall between is part of the design.
- Can I turn part of my house into an in-law suite?
- In many towns, yes. Southport, Leland, Shallotte, Winnabow, Burgaw, Wilmington and mainland Surf City name a unit inside the house. Carolina Beach names only that kind. The suite adds no footprint, though it still needs its own outside door and drains and vents for a kitchen. The town's size cap applies, and so does whatever the inspections office asks of the wall between.
- Does a kitchenette or wet bar make it an ADU?
- None of the ADU rules here names a kitchenette or a wet bar. Most turn on a kitchen or on cooking, so your town or county decides where a small one falls. Its answer sets which rules apply, such as the size cap. The inspections office that issues your permit decides what the wall between needs. Tell us what the suite's kitchen will hold, and we'll look up your town's rule.
The other kinds of ADU.
Regulatory figures on this page summarize the town and county codes each linked city page cites, and the public sources below. Ordinances change; the parcel and the current adopted code decide, and the site analysis confirms both for your lot.
- 2018 North Carolina Residential Code: Sections R102.7.1, R202, R302.3, R310, R311, R314, R315, N1108 and N1109 (ICC Digital Codes)
- 15A NCAC 18E .0105, definitions, including the accessory dwelling unit (NC Office of Administrative Hearings)
- 15A NCAC 18E .0401, design daily flow (NC Office of Administrative Hearings)
- North Carolina Session Law 2023-77, on-site wastewater
- North Carolina General Statute 160D-947, certificates of appropriateness
- City of Wilmington Land Development Code, Sec. 18-200: Accessory dwelling unit (Municode)
- Leland Code of Ordinances, Sec. 66-4: Definitions (Municode)
- Leland Code of Ordinances, Sec. 66-162: Permitted uses, Note 28 (Municode)
- Town of Shallotte Unified Development Ordinance, Secs. 2-2 and 10-4
- Town of Burgaw Unified Development Ordinance, Secs. 8.15 and 8.16
- City of Southport Unified Development Ordinance, Sec. 3.6: Accessory use standards (Municode)
- Town of Carolina Beach Unified Development Ordinance, Sec. 7.3: Definitions (Municode)
- New Hanover County Unified Development Ordinance, Secs. 2.3 and 4.4.4
- Pender County Unified Development Ordinance, Sec. 5.3.2.E
- Town of Surf City Code, Sec. 5.13: Accessory uses and structures (American Legal)
Close enough to share a wall.
Send the address, and tell us whether the suite goes onto the house or inside it. We'll check your town's rule first. We work across Brunswick, New Hanover and Pender Counties, from our home base in Southport.
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