Do I need a permit for addition or structural alteration in Kennesaw?

Yes. In Georgia, addition or structural alteration generally requires a permit, and Kennesaw 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. Cobb County's own permitting office is the Cobb County Development and Inspections, reachable on 770-528-1000 at https://www.cobbcounty.gov/community-development/building-development/permitting. Its online permit portal is https://cobbca.cobbcounty.gov/CitizenAccess/default.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. Cobb 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. Kennesaw's Residential Building Permit covers additions, sunrooms and screened porches, and submittal and resubmittal reviews each take 10 business days. Building permits are issued only to a Georgia-licensed building contractor or to an owner working on the single-family home they own and occupy, and the owner and contractor are jointly responsible for getting the permit before work starts (Code Sec. 18-66). A permit becomes invalid if work does not start within six months of issuance or stops for six months, and the city counts work as progressing only when an inspection is passed. The Plan Review Committee (Building Services, Planning and Zoning, Public Works) meets Thursdays by appointment at no cost; call 770-429-4554 at least three business days ahead.