ADU rules in Decatur

An ADU may be developed in or adjacent to either an existing or new principal dwelling; the city ADU page confirms detached ADUs at the rear of the property. Detached ADUs are subject to the accessory building caps in Sec. 6.8.1.E (1,000 sq ft total accessory floor area, 25 ft and two stories max).

An ADU may be developed in the principal dwelling (attached or internal) or adjacent to it; the city ADU page confirms ADUs can be attached to the main dwelling.

For detached ADUs, Sec. 6.8.1.E separately caps any accessory building at 1,000 sq ft total floor area inclusive of the ADU, garages, and enclosed storage, and at 25 feet and two stories.

The property owner must occupy either the principal dwelling or the ADU as their permanent residence at least eight months per year and may receive no rent on the owner-occupied unit. The building permit application must include a sworn, notarized owner-occupancy statement.

Sec. 6.8.3.A.7 cross-references Section 7.1. The 7.1.3 table lists 1 space per dwelling unit for single-family detached, attached, duplex, and walk up flat uses; how it applies to the ADU as a separate dwelling unit is not spelled out in an ADU-specific row. Sec. 6.3.1.G.2 bars a parking reduction for an ADU accessory to a four-unit walk up flat.

The Sec. 6.2 allowed use table lists ADU as a Limited use (L) in R-85, R-60, R-50, RS-17, RM-18, RM-22, RM-43, and PO: permitted by right subject to the use standards, with no public hearing. Approval runs through a building permit application to the Zoning Administrator with the owner-occupancy affidavit. ADUs are not permitted in NMU, C-1, C-2, C-3, MU, or I districts.

The rent bar on the owner-occupied unit is in Sec. 6.8.3.A.3. STR details (occupancy caps, one STR unit per building in duplexes and flats, local property manager, primary-residence affidavit form) come from the city's official STR page, not from codified UDO text read this session; the STR ordinance's code location was not located in Article 6.