Cameron County, TX Accessory Structures: Shed & Carport Rules (2026)

The county's Flood Damage Prevention and Building Regulations define an 'accessory building' simply as a structure accessory to and incidental to the dwelling, located on the same lot, and Article 5, Section P applies the county's building setback lines to that structure the same as any other. A shed, detached garage or workshop must sit at least 25 feet from the edge of the right-of-way on ordinary public roads, 50 feet back from a major highway or road, and at least 5 feet off adjacent side and rear property lines. Where the recorded subdivision plat imposes a stricter line than these minimums, the plat controls.

Putting up a detached accessory building still takes a permit under the same construction-permit scheme that covers houses and additions. Article 4, Section J.2, item 1(e) prices a detached accessory building or dwelling unit at $38.00 per square foot for permit-fee valuation purposes, separate from the per-square-foot rates used for brick veneer, wood frame, or garage construction attached to the main house. The permit goes through the county Building Inspection Department, and inspectors verify the structure sits outside the setback lines before signing off.

Sheds intended purely as accessory storage, not occupied as a dwelling, are treated differently only for one narrow purpose: the definition of 'start of construction' used to time substantial-improvement deadlines excludes installing an unoccupied garage or shed from that clock, but that exclusion does not waive the underlying permit or setback requirement.