Do I need a permit for shed or accessory structure in Marietta?

Yes. In Georgia, shed or accessory structure generally requires a permit, and Marietta is no exception.

The 200 square foot figure quoted for Georgia is a model figure, not an enforceable statewide threshold. It appears at Section R105.2 of the International Residential Code with Georgia Amendments, but the Georgia amendments delete Chapter 1, Scope and Administration, without substitution and keep it in the code only as a reference and guide for local governments to use in the development of their own administrative procedures. Georgia jurisdictions that follow that guidance exempt one-story detached accessory structures other than storm shelters up to 200 square feet, but the threshold that binds at your address is the local one. Several Georgia cities draw the line lower, so do not assume 200 applies where you live. Sandy Springs requires a permit for detached structures of 120 square feet or larger, and Savannah requires one for a new closed-roof accessory structure over 120 square feet. Ask your building department for the figure that applies at your address. A local size exemption is an exemption from the permit, not from the rules. Zoning setbacks, height limits and lot coverage still apply, and so does the construction standard in the body of the Georgia residential code. Running electrical or plumbing to the shed triggers a separate trade permit regardless of the structure size. 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. A shed on a concrete slab adds impervious surface. A single shed rarely reaches the threshold on its own, but it counts toward the total if you are also adding paving or a pool. 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. Marietta's permit FAQ lists outdoor accessory structures among its examples of work that requires a building permit. The city publishes no size exemption for sheds. In the R-4 district, Zoning Ordinance 708.04(F) places accessory structures to the side or rear of the house at least 10 feet from side and rear lot lines, caps the footprint at 50 percent of the house, and bars building one before the principal building. Other districts carry their own standards. Tents, tarps, and other canvas covered structures are treated as temporary under 708.04(F)(9) and may stand no more than 14 consecutive days and 42 days a year. City of Marietta addresses (Cobb tax district 4, MARIETTA) are permitted and inspected by the City of Marietta Building Inspections office at 205 Lawrence Street, 770-794-5659. Addresses in tax district 9, UNINCORPORATED, go to Cobb County instead.