Decatur, AL Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- PRD-1 to PRD-4 coverage
- 25 percent of gross development
- PRD-5 and PRD-6 coverage
- 30 percent of gross development
- PRD-7 and PRD-8 coverage
- 35 percent of gross development
- RD and RD-2 site coverage
- 50 percent by all structures
- PRD common open space
- At least 10 percent of total area
- R-1 to R-4 maximum building area
- None specified
Summary
In the City of Decatur, Alabama, the zoning code caps building coverage at 25 to 35 percent of the gross development in Planned Residential Development districts (Sec. 25-10.1) and at 50 percent in the RD and RD-2 redevelopment districts. The R-1 through R-5 district rows list no maximum building area and rely on yard setbacks.
(I)PRD Districts, and layout and design requirements. PRD Districts together with applicable minimum yard, height, area coverage, and density requirements for each district are hereby established as follows: PRD Districts Maximum Dwelling Units Per Gross Acre Maximum Building Height Stories Feet Maximum Percentage Lot Coverage of Buildings on Gross Development Building Setback Requirements in Feet (at Exterior Boundaries of PRD Site) Front Rear Side PRD-1 2.0 2.5 35 25 40 45 15 PRD-2 2.6 2.5 35 25 40 45 15 PRD-3 3.0 2.5 35 25 35 40 8 PRD-4 3.5 2.5 35 25 35 40 8 PRD-5 4.25 3.0 40 30 30 35 8 PRD-6 5.0 3.0 40 30 30 35 8 PRD-7 12.5 N/A N/A 35 25 30 8 PRD-8 20.0 N/A N/A 35 25 30 8
Full Breakdown
Decatur's zoning chapter caps building coverage only in certain districts, and the clearest numbers sit in the Planned Residential Development (PRD) table in Sec. 25-10.1(I). The table lists a maximum percentage lot coverage of buildings on the gross development: 25 percent in PRD-1 through PRD-4, 30 percent in PRD-5 and PRD-6, and 35 percent in PRD-7 and PRD-8. Density climbs with coverage, from 2.0 dwelling units per gross acre in PRD-1 to 20.0 in PRD-8. A PRD must be a tract of at least five acres, and Sec. 25-10.1(H)(2) requires at least 10 percent of the total area to be usable common open space, which cannot include streets, alleys, vehicular drives, parking and loading areas, or space reserved for one tenant or owner.
Outside the PRD districts the conventional residential districts do not cap coverage by percentage. The R-1, R-2, R-3 and R-4 rows in Sec. 25-10.8 through 25-10.11 read Maximum building area: None specified, the R-5 row says the same, and the R-1E estate district reads "Maximum coverage—None specified." Yard setbacks, not a percentage, decide how much of the lot can be built on.
The redevelopment districts are the other exception. Sec. 25-11.2(c)(5) for the RD district and Sec. 25-11.3(b)(6) for RD-2 both set the maximum building site coverage by all structures at fifty percent, and both districts describe lot coverage as one of the flexible standards they offer property owners. New development in the RD district needs planning commission site plan approval before any related building permit issues (Sec. 25-11.2(c)(12)).
An approved PRD development plan is recorded with the Morgan County probate court and, under Sec. 25-10.1(F), limits and controls the issuance of permits and restricts the use of all land and structures in the district.
Violations & Fines
Sec. 25-26 fines a person who violates the zoning chapter not less than $2 and not more than $100 plus court costs for each offense, and each day the violation continues is a separate offense. Under Sec. 25-24 the building inspector can seek an injunction or other proceeding to abate a structure built in violation of the chapter, and Sec. 25-6 bars the inspector from issuing a permit for plans that do not conform.
Frequently Asked Questions
Is there a lot coverage limit for a house in an R-1 district?
What coverage does a Planned Residential Development allow?
How much of a lot can be covered in the RD redevelopment districts?
Does the 10 percent open space in a PRD include driveways and parking?
Sources & Official References
Other rules in Decatur
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