Accessory Dwelling Unit (ADU) Size Regulations in Fayetteville

In the City of Fayetteville, a single lot is permitted to have a maximum of 1,200 square feet of habitable space dedicated to Accessory Dwelling Units (ADUs). This 1,200-square-foot limit represents the total cumulative area allowed; therefore, if a property owner installs the maximum of two permitted ADUs, their combined square footage must not exceed this cap. While most accessory structures are limited to 50% of the size of the principal structure, the City of Fayetteville specifically exempts ADUs from this 50% size restriction.

Maximum Square Footage and Quantity Standards

The City of Fayetteville Unified Development Code (UDC) provides specific administrative standards for the development of ADUs. To qualify for administrative approval by the Zoning and Development Administrator, the project must adhere to the following dimensions and quantity limits:

Standard Type	Requirement
Maximum Habitable Space (Per Lot)	1,200 square feet
Maximum Number of ADUs (Per Lot)	2 units
Combined Area for Two ADUs	1,200 square feet total
Size Relative to Principal Dwelling	Exempt from the 50% size limit for accessory structures
Maximum Occupancy	One (1) family per ADU
Building Height	Subject to underlying zoning (Administrative) or 3 stories (Design Review)

Development Criteria and Exceptions

Under the City of Fayetteville UDC, ADUs are intended to increase the housing stock in a manner compatible with established neighborhoods while providing more attainable housing options [Section 164.19(A)].

Size and Structure

The 1,200-square-foot limit applies to "habitable space." Accessory dwellings may be created as interior units (such as a basement apartment), attached additions to the primary home, or detached structures [Section 164.19(C)(4)]. For the purposes of calculating the size of a detached ADU, only the habitable area is counted toward the 1,200-square-foot limit.

Variances for Increased Size

If a property owner wishes to exceed the 1,200-square-foot limit or the height requirements, they must apply for a variance. The Fayetteville Planning Commission handles these requests and will evaluate them based on whether unique circumstances exist and if the larger unit would adversely impact neighboring properties [Section 164.19(D)].

Zoning and Infrastructure

ADUs must comply with all underlying zoning requirements of the City of Fayetteville, including setbacks and building area coverage, with the exception of density limits. Additionally, the property must have adequate infrastructure (water, sewer, gas, and electric) to serve the additional units [Section 164.19(B)].

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