ADU FAQs

What is an ADU?

An Accessory Dwelling Unit (ADU) is a small, self-contained home that is located on the same lot as a primary dwelling.  ADUs may be detached, attached, or internal to the primary dwelling. An ADU may also be located above a garage or in a basement. They can be one story or two stories. They include a living room, sleeping area, kitchen, bathroom, and have a lockable external entrance. An ADU may be located above a garage. ADUs may be detached, attached, or internal to the principal dwelling.

Accessory Dwelling Unit (ADU) rules and regulations apply to an independent dwelling unit or units located on the same lot as an existing principal (detached or attached) dwelling for single-unit living. ADUs should be independent of and smaller than the main dwelling.

All ADUs must meet minimum fire-resistant separation when required by the NC State Residential Building Code.

Can I build in a Historic Overlay District (HOD)?

Yes. Residents who want to build in an HOD should follow the Raleigh Historic Development Commission (RHDC) design guidelines for their HOD and need to obtain a Certificate of Appropriateness (COA) before beginning construction. 

Is additional parking required?

No. Additional parking does not have to be provided with an ADU.

I am part of a Homeowners Association (HOA), can I build an ADU?

Maybe. Contact your HOA and ask if ADUs are permissible in your neighborhood and if there are any additional design requirements.

What zoning districts allow ADUs?

ADUs are allowed in the following zoning districts: R-1, R-2, R-4, R-6, R-10, RX, OX, NX, DX, and CX.

What type of "use" is an ADU?

Only residential uses are permitted in ADUs, and they must meet the requirements of Section 2.6.3 or Section 3.6.2 of the UDO.

What are the size requirements?

ADUs shall be located on the same lot as a principal dwelling and meet both of the following:

1. The gross floor area of the accessory dwelling shall be less than the gross floor area of the total principal dwelling.
2. Shall be affixed to or constructed on a permanent foundation and not be a manufactured home or moveable structure.

See the accessory structures information in UDO Section 2.6.3 and Section 3.6.2 for size restrictions. 

How many ADUs can I have on my property?

Only one ADU is allowed per single lot unless located in a Frequent Transit Area (as referenced in UDO Section 2.6.3 or 3.6.2). In these areas, two ADU units may be added.

Can my ADU be on wheels?

No. It must have a permanent foundation.

Can I sell my ADU?

No. ADUs cannot be sold apart from its principal dwelling unit.

Can I Rent My ADU?

If you build the ADU yourself, you cannot rent it. Per NC General Statute §87-1, if an Owner/Builder exemption is being claimed in lieu of licensed contractors (building or trade), a statement from the owner that the ADU will be built solely as Not For Rent is required prior to permit issuance. The statement will become part of the permanent record for the project. Please refer to NC General Statute §87-1 for further details on the Owner Exemption qualifications.

Otherwise, a licensed NC General Contractor is required for projects with a total project valuation greater than $40,000.

As a homeowner, can I build my own ADU?

If you build the ADU yourself, you cannot rent it. Per NC General Statute §87-1, if an Owner/Builder exemption is being claimed in lieu of licensed contractors (building or trade), a statement from the owner that the ADU will be built solely as Not For Rent is required prior to permit issuance. The statement will become part of the permanent record for the project. Please refer to NC General Statute §87-1 for further details on the Owner Exemption qualifications.

Otherwise, a licensed NC General Contractor is required for projects with a total project valuation greater than $30,000.

Will my ADU permit application be reviewed under Residential or Commercial Building Code?

If the ADU being applied for (as a stand-alone permit or as part of an application with a primary dwelling) results in two total units on a single parcel, the application will be reviewed under NC State Residential Building Code. If it results in three units on a parcel, in general the ADU can be reviewed under residential code if no more than two of the three units are attached to one another, to be determined by the buildings department case reviewer. All applications resulting in four or more total units on a single parcel are reviewed under NC State Commercial Code.