Do I need a permit for addition or structural alteration in Unincorporated Gwinnett County?

Yes. In Georgia, addition or structural alteration generally requires a permit, and Unincorporated Gwinnett County is no exception.

Additions and any change to load-bearing walls require a permit and reviewed plans in Georgia; removing or altering a bearing wall usually needs engineered details. Additions may trigger energy-code, zoning, and setback review, so confirm the full scope before starting. Gwinnett County's own permitting office is the Gwinnett County Planning and Development, reachable on 678-518-6020 at https://www.gwinnettcounty.com/government/departments/planning-development/services/building-services. Its online permit portal is https://aca-prod.accela.com/gwinnett/welcome.aspx. It issues permits for the unincorporated county. If your city does not run its own building department, and many smaller Georgia municipalities do not, this is the office that will handle the job. Gwinnett County sits inside the Metropolitan North Georgia Water Planning District, created by the Georgia General Assembly in 2001. Every local government in the District, cities included, has to adopt the District's model post-construction stormwater ordinance or an equivalent one at least as effective, so these rules follow you into any city in the county rather than stopping at the unincorporated line. An addition adds roof area, which counts as impervious surface, and a large one combined with new driveway or patio work can reach the local threshold. In practice the thresholds are aimed at larger development rather than ordinary homeowner work, so most single-family projects sit below them. Cobb County, for example, publishes its trigger as adding more than 5,000 square feet of impervious surface or disturbing more than an acre. Each local government sets its own figures, so check yours before assuming. Where it does apply, the current standard is to retain the first 1.0 inch of rainfall on the site to the maximum extent practicable, which usually means a detention or infiltration feature rather than just grading water to the street. Gwinnett County Planning and Development issues house addition permits, and a construction permit is issued to the contractor of record after plan review and fees. A homeowner may pull the permit with proof of ownership and a signed Property Owner as Contractor Affidavit. Under Construction Code 106.3.1, contractors must show a Georgia business license at application, except an owner working on a single-family home that is the owner's primary residence. Under UDO 230-60.1, unenclosed decks, porches, steps and landings may extend into the side or rear setback but no closer than 5 feet to a property line. Under 106.7, a permit expires if work does not start within 180 days or is suspended for 180 days without a passed inspection.