Permits and Site | Building Code

Building a Duplex to Fourplex in Atlanta: Permits and Georgia Building Codes

Two levels of government decide how a small residential building gets built in Atlanta. The State of Georgia sets the construction codes through its Department of Community Affairs (DCA). The City of Atlanta issues the permits and checks zoning, trees, stormwater and fees before work starts and before anyone moves in. This page explains which state code a duplex, triplex or fourplex follows, the fire sprinkler rule, the dates on the 2024 code editions, and the City checks tied to a building permit. The facts come from DCA's documents and from the City Code as updated September 24, 2026.

Which Code Covers Which Building

Sources: Georgia amendments to the International Residential Code, 2024 edition and Georgia amendments to the International Building Code, 2024 edition. The last row is a reading of the two scope clauses.

The dividing line is in the scope clause of the Georgia residential code. It applies to "detached one- and two-family dwellings and townhouses separated by a 2-hour fire-resistance-rated wall assembly, not more than three stories above grade plane in height with a separate means of egress and their accessory structures." In plain words: a house, a duplex, or a row of attached homes where each home is divided from the next by a wall built to resist fire for two hours, has its own way out, and rises three stories or fewer above the ground level around it.

The Georgia building code repeats the rule. It applies to "every building or structure," and its first exception sends one- and two-family dwellings and qualifying townhouses to the residential code. A building with three or four homes that is not a row of townhouses meets neither description in the residential code, so it is built under the building code, which Georgia names the State Minimum Standard Building Code. Atlanta's Zoning Ordinance uses the same number: Section 16-29.001 defines a multi-family dwelling as "a building containing three or more dwelling units."

The choice affects design from the first drawing. A fourplex laid out as four townhouses side by side, each with a 2-hour wall and its own exit, stays in the residential code. A fourplex with homes stacked above one another moves to the building code. Decide the layout with your architect before the zoning application, because the zoning district must also permit it. The duplex, triplex and fourplex page lists the districts.

The 2024 Code Editions and Their Dates

Georgia's codes are adopted by the DCA Board. The DCA construction codes page describes two kinds. Mandatory state codes "are applicable to all construction regardless of whether they are locally enforced." Permissive state codes "are only applicable if a local government chooses to adopt and enforce one or more of these codes." Each code is a base code, such as the International Building Code published by the International Code Council, plus a set of Georgia amendments.

DCA's own documents give different dates for the 2024 editions. The table shows what each one says.

Each row was read from the linked document in October 2026.

The announcement is the clearest statement, and it names eight codes: the 2024 International Residential, Building, Fuel Gas, Mechanical, Plumbing and Swimming Pool and Spa Codes with Georgia amendments, the 2024 International Fire Code as adopted by the Safety Fire Commissioner, and the 2026 Georgia amendments to the 2023 National Electrical Code. It says they were adopted under O.C.G.A. 8-2-23 and recommends that city and county governments with local amendments on file review those amendments against the new codes.

This guide does not say which edition applies to a permit filed today. Ask Atlanta's Office of Buildings which edition it will review your drawings against, and get the answer before your architect starts the construction drawings. For questions on the state codes themselves, the announcement gives the DCA Office of Construction Codes and Industrialized Buildings at (404) 679-3118.

Georgia's State Minimum Codes

Source: Georgia DCA, Current State Minimum Codes for Construction, as the page read in October 2026.

The residential code works together with three other state codes. The Georgia amendments delete three parts of the International Residential Code and replace each with a separate state code: energy conservation (Chapter 11) is replaced by the Georgia energy code, plumbing (Chapters 25 to 33) by the Georgia plumbing code, and electrical (Chapters 34 to 43) by the National Electrical Code with Georgia amendments. A duplex therefore has to meet four state codes: residential, energy, plumbing and electrical.

The energy code is the oldest edition on the list. It is the International Energy Conservation Code, 2015 Edition, with Georgia Supplements and Amendments, and DCA's page shows amendment files dated 2020, 2022 and 2023. The December 2025 announcement does not list a new energy code among the codes adopted for 2027.

The Georgia amendments also delete Chapter 1 of the International Residential Code, "Scope and Administration," and keep it only "as a reference and guide for local governments to use in the development of their own Administrative Procedures." This is why the state documents say nothing about application steps, permit fees or review times. Each city sets those. In Atlanta they come from the Office of Buildings.

Fire Sprinklers: Optional Up to Two Homes

The Georgia residential code amendments carry an "important note" that quotes state law, O.C.G.A. 8-2-4: "Neither the state residential and fire building code nor any residential and fire building code adopted by a political subdivision of the state adopted after May 24, 2010, shall include a requirement that fire sprinklers be installed in a single-family dwelling or a residential building that contains no more than two dwelling units." A political subdivision is a city or a county, so the City of Atlanta cannot add a sprinkler mandate for a house or a duplex.

The amendments then rewrite Section R309.1 of the residential code: "Installation of an automatic residential fire sprinkler system shall be optional and not mandatory in one- and two-family dwellings and townhouses." An owner who chooses sprinklers must have them designed and installed to NFPA 13D, the National Fire Protection Association standard for sprinklers in homes. The same amendments require carbon monoxide alarms in dwelling units in new construction.

The statute covers buildings with no more than two dwelling units. For a triplex or fourplex built under the building code, the Georgia amendments include a table called the Codes Reference Guide. It lists "LSC" as the primary code for means of egress, fire alarm systems and the minimum construction standard for sprinkler systems, and DCA's code list sends questions on the Life Safety Code (NFPA 101) to the State Fire Marshal's Office. VanPlex did not read the Life Safety Code, so this guide does not say whether a given three- or four-home building needs sprinklers. Ask the Office of Buildings before design starts.

Existing Buildings and Conversions

Turning an existing house into two homes is a different job from new construction, and a different code can apply. The Georgia building code amendments say: "By Georgia law, the International Existing Building Code is a permissive or optional State Minimum Standard Code." Its provisions "are not mandatory or applicable unless specifically referenced in the adopting ordinance of local governments."

Atlanta has adopted it. Section 8-2201 of the City Code says: "The International Existing Building Code, as amended from time to time, is hereby adopted as the code governing 'existing buildings' in the City of Atlanta." The section dates from Ord. No. 2016-44, adopted November 30, 2016. DCA's list shows the 2018 edition of that code with Georgia amendments as the current permissive edition, and the document attached to the December 2025 announcement includes Georgia amendments to the 2024 edition dated January 1, 2027.

One older section of the City Code needs a caution. Section 8-2071 still names the "Standard Building Code, 1982 Edition" as the building code of the City. Do not rely on it for the edition in force. The mandatory state codes apply to all construction in Georgia whether or not a local ordinance has been updated.

What the City of Atlanta Checks With a Building Permit

The City Code gives permit work to one office. Section 8-1007 lists the duties of the bureau of buildings, which include "enforcing all construction codes," "issuing permits" and "handling the administration, interpretation and enforcement of the zoning ordinance." Newer sections of the Code call the same office the "Department of City Planning, Office of Buildings." Several other City rules attach to the permit.

Source: Atlanta Code of Ordinances as updated September 24, 2026. Each section number links to its chapter.

Zoning comes first. Section 8-2003 says applications "which are not in compliance with that ordinance shall not be approved or permitted." A permit reviewer cannot approve a second or third home that the district does not allow, and a variance cannot grant one either. That request is a rezoning, covered on the rezoning, NPU and variances page.

Two rules control the last step. A certificate of occupancy is the City's written confirmation that a building may be lived in. The City will not issue it while impact fees are unpaid, or before the City Arborist has made a final inspection. The impact fees page and the trees and stormwater page give the amounts and the standards.

Small buildings do get permitted. The US Census Bureau's Building Permits Survey for 2025 counts 78 two-unit buildings and 64 buildings of three or four units authorized by permit in the City of Atlanta.

Demolition Permits

A project that replaces an old house starts with a demolition permit, and Atlanta ties that permit to the plan for the lot. Section 8-2076.1 requires every demolition permit application for a residential structure to "list the reason(s) for seeking said demolition permit, including whether the proposed future use of the subject property shall require rezoning, a special use permit, or an amendment to the comprehensive development plan." The applicant attaches the drawings, permits and other documents that show the planned use.

The application goes to the planning director, who decides whether the planned use needs one of those approvals. If it does, the demolition permit "shall be held until the subject property has been rezoned, the special use permit granted, or the comprehensive development plan amended." If the purpose is only to create open space, the permit is held until the applicant brings forward a redevelopment proposal. The exception is a structure found unfit for human habitation or declared unsafe: those permits are granted.

The practical result for a small multifamily project: an owner who plans a triplex on a lot that needs a rezoning cannot demolish the house first. The rezoning has to be granted before the demolition permit is issued.

Section 8-2076 sets the time limit. Demolition of a structure "equivalent in size to a four-unit residential structure or less will be limited to 60 days." The person doing the work must cut off and cap all utilities at the street and remove the debris and exposed foundations within that time. The tree ordinance adds a rule: the City Arborist permits tree removal for a demolition only when the demolition cannot be done without it.

Zoning Application Fees That Come Before the Permit

The only fees VanPlex could read from the City Code are the zoning application fees in Section 6-1007, last amended by Ord. No. 2019-39 on July 10, 2019. They apply before the building permit, when a project needs a rezoning, a special permit or a subdivision.

Source: Atlanta Code Sec. 6-1007, as printed in the code updated September 24, 2026.

What VanPlex Could Not Read, and Where to Ask

The City's main website returned an access error to every request during research in October 2026. Four things on this topic are therefore missing from this page, and you need each one before you set a schedule or a budget.

• Building permit fees. The basis for the fee and the current amounts. Ask the Office of Buildings in the Department of City Planning.
• How to apply. The name of the online permit system, the documents it asks for and the order of reviews. Ask the Office of Buildings.
• Review times. The City Code sets no review time for a building permit in the sections read for this guide. Ask the Office of Buildings for current times.
• The code edition and local amendments. Which edition of the state codes the City reviews against on your filing date, and which Atlanta amendments apply. Ask the Office of Buildings. For the state side, ask the DCA Office of Construction Codes and Industrialized Buildings.

Two more offices answer site questions. The City Arborist in the Department of City Planning administers the tree ordinance on private property. The Department of Watershed Management administers the stormwater article.

Where to Go Next

Related on VanPlex: the Atlanta multiplex guide overview, building codes for a duplex to fourplex in Texas and the missing middle guide.

Frequently Asked Questions

Official sources (checked October 2026)