Bossier Parish, LA Accessory Structures: ADU Rules (2026)

Section 126-803 of the Bossier Parish zoning code sets the size and placement rules for an accessory dwelling unit, or ADU, once it clears the eligibility test in subsection (a): the unit must go in the rear or side yard of an existing owner-occupied single-family home in the R-A district, or the rear yard in R-1 or R-2 districts within the unincorporated Benton-Parish Metropolitan Planning Commission planning area. The permitted heated area scales with the lot: up to 800 square feet on a lot up to 12,000 square feet, 1,200 square feet on a lot from 12,001 to 25,000 square feet, 1,600 square feet on a lot from 25,001 square feet to one acre, and on lots larger than an acre, up to half the heated area of the primary dwelling or 1,600 square feet, whichever is greater.

Placement is tightly controlled: the ADU must sit at least twice the required side yard setback away from the primary dwelling, and it cannot occupy any required yard at all. Independent of that separation rule, the unit needs a rear yard setback of at least 20 feet and a side yard setback of at least ten feet. The ADU must also be built on a permanent foundation, not a manufactured or modular home or any movable structure, and its colors, materials and design must substantially match the principal dwelling.

Approval runs through 'planning approval' under the Metropolitan Planning Commission's procedures rather than a building permit alone, and the approval cannot override a subdivision's own covenants against a second dwelling.