If Cobb commissioners approve accessory dwelling units on October 27, owners in East Cobb would still have one more step before building one. Under Cobb County's draft code, the owner has to sign an affidavit stating that the backyard unit does not conflict with "any applicable covenants, conditions, deed restrictions, or bylaws." For a buyer looking at homes along Johnson Ferry, Lower Roswell or Sandy Plains, that means the county vote settles only half the question. The other half is in the subdivision's recorded documents.
Here is where things stand. Unincorporated Cobb does not allow ADUs today, while Acworth, Mableton, Marietta and Powder Springs already do, according to the East Cobb Beacon. Cobb's hearing notice sets the Planning Commission hearing for Tuesday, October 6. Board of Commissioners hearings follow on October 13 and October 27, with the vote on October 27. All of it is still a proposal.
The draft, rule by rule
The proposed standards appear in the county's Chapter 134 draft. Each rule narrows which lots could actually use the new allowance.
| Draft rule | What it means on an actual lot |
|---|---|
| Up to 850 sq ft or 50% of the main home, whichever is smaller | A 1,400 sq ft ranch would top out at 700 sq ft |
| One story, no taller than the main home | Two-story garage apartments are out |
| Rear yard only, within the main home's side and rear setbacks | Narrow or shallow backyards may have no room |
| Lot-wide impervious surface limit still applies | Pools, patios and long driveways count against the space left |
| Connected to the main home's utility meters | No separate meter for the unit |
| At least one off-street parking space | Some driveways would need to be widened |
| No short-term rentals | Not a vacation-rental play |
| Owner lives in the main home or the ADU | Not an absentee-investor play |
| One ADU per single-family lot | No stacking units |
| Owner signs a covenant affidavit | HOA and deed restrictions come into play |
Parking may be stricter than the table shows. OpenPublica's summary of the commissioners' September 22 work session records that if a single-family home already requires two off-street spaces, more parking would be needed to accommodate an ADU.
The permit path is also an open question. In the draft, the ADU standards sit inside Sec. 134-37, the code section titled "Special land use permits." If that placement holds, each backyard unit would appear to go through permit review rather than being allowed outright. Confirm this with Cobb Community Development before counting on it.
The covenant affidavit
The draft's definition says an ADU can be attached to the main home or detached from it. Neither type gets past the affidavit unless the owner can sign it truthfully. Many East Cobb homes sit in established subdivisions with recorded covenants. The draft makes those documents part of the approval.
The affidavit isn't new. The 2024 Cobb County draft had the same requirement. Opponents still worried about enforcement two years ago. At the November 2024 Planning Commission hearing, Jill Flamm of the East Cobb Civic Association said ADUs could "destabilize and destroy many existing single-family neighborhoods" and that homeowners associations would be able to do little to prevent them, as East Cobb News reported.
The way the text works is simple. Compliance rests on the owner's signature. Whether an HOA objects is a matter for the HOA's own documents and its own enforcement. For buyers, this changes what to ask during due diligence. "Does Cobb allow this?" may soon get a different answer than "Does my subdivision allow this?" Only the second answer is specific to the house you're considering.
Owner occupancy raises a similar enforcement question. At the September 22 session, the community development director supported requiring the owner to live on the property but acknowledged it would be hard to enforce. Staff explained that they can only talk to the owner or a resident and cannot always verify who actually lives there.
Why East Cobb is at the center of the vote
East Cobb has the most at stake, and the 2024 record shows why. In 2024, North Cobb Commissioner Keli Gambrill cited a figure that 85 percent of properties eligible for ADUs would be in her district and in Commissioner JoAnn Birrell's East Cobb district. The Planning Commission recommended denial 5–0 that November. On November 12, 2024, commissioners voted 5–0 to withdraw the proposal after hearing vocal opposition. That October, Birrell called the proposal "a bad idea" and argued that homeowners could already add on to their homes. At the withdrawal, she said existing code already accommodated in-law suites.
The 2026 language is nearly identical, and the early signals look familiar. Gambrill told the Marietta Daily Journal on September 9 that ADUs would crowd neighborhoods and strain parking without meaningfully addressing affordable housing. Birrell said she does not plan to support the proposal, citing enforcement and setback concerns. "I'd like to hear from the public what they think, but right now I do not support it," she said. Chairwoman Lisa Cupid first proposed ADUs to address housing affordability.
So a buyer who's counting on a backyard unit is betting on two things: how five commissioners vote on October 27, and what one subdivision's covenants say.
The front-door sentence and homes with basement suites
The same draft changes how a single-family home is defined, and this may matter more to buyers than the ADU rules. The proposed text adds this sentence: "All rooms in a dwelling unit shall be accessed through the common front door." The 2024 version said "front or primary door."
The draft doesn't explain how the county would apply this to existing homes that have a separate-entrance basement suite. If a walkout lower level with its own door is part of why you like a house, ask the county how this language would affect it.
The occupancy rules change too. The single-family definition would go from one unrelated adult to three, or from two unrelated adults with their children or grandchildren to four. The definition of family would also expand to cover guardianship. The existing requirement of 390 square feet of living space per adult occupant stays in place.
Where East Cobb's new housing comes from now
Without ADUs, new homes in East Cobb arrive through larger projects, one site at a time, and at set price points.
- Shallowford Pointe: Toll Brothers is doing site work at Johnson Ferry Road and Waterfront Drive for 75 detached homes from 2,319 to 3,659 square feet. In April, East Cobb News reported starting prices of $1 million and said advance sales were expected later in 2026. As of October 4, the builder's site still lists it as a future community with home designs "Coming Soon" and no posted prices.
- East Cobb Walk: On the former Sprayberry Crossing site, the EVOQ senior apartments were leasing as of August and Toll Brothers was finishing the townhomes. On October 4, the builder listed eight quick move-in homes from $470,000 to $690,000.
- The Haven: Eastside Church's proposed senior community on Lower Roswell Road would have 103 units, with reported starting charges of $6,000 a month. The Planning Commission recommended denial 4–0, and the Board of Commissioners hearing was continued to October 20.
Each of these went through its own public process. An ADU would add a unit inside a lot that already exists, which is why the covenant question matters so much.
The broader market gives buyers room to check. In September 2026, Georgia MLS reported 2,799 active residential listings across Cobb County, up 15.5% from September 2025. Units put under contract fell 26.9% to 442, and the median sale price of $417,000 was up 0.4%. These numbers are countywide and cover Georgia MLS activity only, but they point to a fall market with more inventory and less urgency. That leaves time to request covenants before writing an offer.
What to settle before an offer
- Get the recorded covenants and HOA bylaws early. Look for language on accessory structures, second dwellings or rental restrictions. The affidavit depends on them.
- Measure the rear yard against setbacks and the lot's impervious surface limit. A pool or wide patio can use up the space.
- Check parking. Count the off-street spaces the house already needs and see whether one more fits.
- Ask Cobb Community Development about the permit path and how the common-front-door language would treat any separate-entrance space in the house.
- Watch the October 27 vote. Until then, every ADU plan is conditional.
None of this is legal advice. Your HOA documents and the county are the final word.
Quick answers
Can I build an ADU in unincorporated East Cobb today? No. Unincorporated Cobb doesn't allow them now. The proposal comes up for a vote on October 27.
Could I rent out an ADU? The draft bans short-term rentals and requires the owner to live in either the main home or the ADU.
Does the draft apply inside the City of Marietta? No. Marietta already allows ADUs under its own rules.
If you're weighing an East Cobb home and a future backyard unit is part of the plan, The Mike Price Team can help you get the covenants, lot details and county answers lined up before you commit. And if you already own in East Cobb and want to know how the October vote might affect your property's value, start with a Free Home Valuation.
