2026-09-10 · Louisiana · Regulation

What happened. Louisiana has no statute giving an owner the right to build an accessory dwelling unit over an association's objection, and no statute letting an association prohibit one. What it does have — and what is missing from most Louisiana discussion of the subject — is a construction-code definition of an ADU with a state plan-review requirement attached.

The code text

From LAC 17:I.107, the state's adoption of the International Residential Code:

“Accessory Dwelling Unit (ADU) Is a structure, accessory to and incidental to that of the dwelling, and that is located on the same lot. A single unit providing complete independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking and sanitation. Accessory Dwelling units shall be designed and constructed in accordance with the Louisiana State Uniform Construction Code. This shall include plan review and inspection by a currently registered LSUCCC inspector.”

This is not new. The section's historical note shows it as amended at LR 50:400 and LR 50:404 — the March 2024 Louisiana Register — so the plan-review duty has been in force for two and a half years. It was republished in a June 2026 emergency rule, which is how it surfaced again.¹

The emergency rule it was republished in

The code council amended LAC 17:I.107 by Declaration of Emergency effective June 1, 2026, published at page 652 of the May 20, 2026 Register, for a reason it stated in plain terms:

“the LSUCCC has found an immediate need to adopt by emergency process the attached Rule relative to amending the 2021 International Residential Code by amending Chapter 9, Roof Assemblies by adopting additional language under Section 905.1.1, Underlayment. As we approach the 2026 hurricane season, which carries a high risk of destructive wind events and significant water intrusion—particularly at the roof's drip edge—this amendment is necessary to ensure a watertight roofing system that performs in accordance with IBHS Fortified Standards.”

The rule is effective “June 1, 2026, and will remain in effect 180 days, unless renewed by the agency head of the council, or until permanent rules are promulgated in accordance with law” — so to roughly November 28, 2026.

1. Louisiana Administrative Code Title 17 (Construction), last amended May 2026 — LAC 17:I.107 with the ADU definition and its LR 50:400/404 provenance ↩
2. Louisiana Register Vol. 52, No. 5 (May 20, 2026) — Declaration of Emergency at p. 652 ↩
3. Lake Terrace Property Owners Ass’n v. City of New Orleans, BZA, No. 2024-CA-0577 c/w 0758 (La. App. 4 Cir. Feb. 18, 2025) — slip opinion ↩
4. La. R.S. 9:1141.14 — amendment thresholds and the forty-percent design-standards trigger ↩