Decatur, AL Accessory Structures: Shed & Carport Rules (2026)

Sheds fall under the accessory structure rules in Decatur's zoning chapter. Sec. 25-2 defines an accessory structure as a detached minor building in the rear of the main building, with masonry or frame walls and a roof, one or two stories high, necessary as an adjunct to the use of the main structure. Sec. 25-10 allows accessory structures in every R residential district and sets the setback: 5 feet from the rear lot line and 5 feet from each side lot line, compared with 35 feet for public and semi-public buildings. The R-6 semi-attached district keeps the 5-foot rear setback but makes the accessory side yard match the main structure (Sec. 25-10.2).

Attachment changes the math. A carport, porte-cochere, porch or similar structure attached to the main structure, or standing within 5 feet of it, is treated as part of the main building and takes the full setback and side yard of its district instead of the 5-foot accessory setback. A shed built close to the house therefore has to meet the house's setbacks.

Sec. 25-10 lists Maximum building area as "None specified," and no square-footage cap for a shed appears in that section. Sec. 25-18 limits a residential lot to one main structure plus permitted accessory structures and bars living quarters in them. In the R-1E estate district, Sec. 25-10.7 lists accessory buildings including private garages, barns, tack rooms and a guest house with no kitchen facilities, and puts buildings that house horses or horse feed 75 feet from any property line.

Permits come first. Sec. 25-5 makes it unlawful to start excavation or construction of any building or other structure, including accessory structures, until the building inspector issues a building permit. Under Sec. 25-6 the application needs a scale plan showing the lot's shape and dimensions and the size and location of every building on it.