Lafayette Parish, LA Accessory Structures: ADU Rules (2026)
ADU rules in Lafayette Parish, LA, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Applies to
- City of Lafayette and unincorporated parish
- Units per lot
- One accessory apartment
- Size cap
- 25% of main home or 800 sq ft
- RS/RM rear setback
- 5 feet minimum
- Detached unit
- Building permit required
Summary
Lafayette's code allows one accessory apartment per lot, citywide and in the unincorporated parish, capped at 25 percent of the main home's floor area or 800 square feet, whichever is larger, with a building permit required for any detached unit.
(a)Applicability. This section applies to the City of Lafayette, and the unincorporated areas of Lafayette Parish.(b)Only one accessory apartment is allowed per lot.(c)Maximum living area is the greater of:a.Twenty-five percent of the gross floor area of the principal dwelling unit, orb.Eight hundred square feet.(d)An accessory apartment may not be sold separately from the principal dwelling unit but may be rented.(f)An accessory apartment located in a detached structure constructed after the effective date of this section requires a building permit.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 65).
Full Breakdown
Sec. 89-74 of the Lafayette City-Parish Consolidated Government Code applies in the City of Lafayette and unincorporated Lafayette Parish alike. Only one accessory apartment is allowed per lot, and its living area can't exceed the greater of 25 percent of the principal dwelling's gross floor area or 800 square feet. The unit can be rented but never sold apart from the main house. It must meet the principal structure's setbacks, though RS and RM zoned lots get a reduced 5-foot rear setback. A detached accessory apartment built after February 1, 2023 needs a building permit with a scaled site plan showing the lot, the principal building's floor area, and the accessory apartment's location, setbacks and floor plan.
Violations & Fines
Building without a permit for a new detached accessory apartment, or exceeding the 800-square-foot/25-percent size cap, is a code violation subject to enforcement by the LCG.
Frequently Asked Questions
Can I sell the accessory apartment separately?
Do I need a permit for a detached accessory apartment?
Sources & Official References
Other rules in Lafayette Parish
How Lafayette Parish compares: Easiest Cities to Build an ADU·Compare Lafayette Parish to another location·View the Louisiana accessory structures overview
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