Cobb's Backyard Cottage Vote Won't Put Cottages Behind East Cobb Homes Anytime Soon

On Oct. 27, 2026, the Cobb County Board of Commissioners is scheduled to vote on an amendment that would allow detached accessory dwelling units on single-family lots in unincorporated Cobb, including East Cobb. If you're touring homes in 30062, 30066, 30067 or 30068 and considering a future cottage out back, that vote matters less to your purchase than it seems. Even with a yes vote, the rule is built to arrive slowly, one lot and one public hearing at a time, and only where private covenants allow it. For a house you buy this fall or next spring, the in-law space you can count on is the attached kind the county code already permits.

Where the proposal stands this month

The amendment is still a proposal. Cobb's own explainer, posted Oct. 8, says the changes "are under consideration and have not been adopted," and it lists Board hearings on Oct. 13 and Oct. 27. According to the Marietta Daily Journal, the Cobb Planning Commission voted unanimously on Oct. 6 to recommend approval. That is a recommendation to the Board, not a decision.

The county has been here before. On Nov. 12, 2024, commissioners voted 5-0 to withdraw an earlier ADU proposal after public opposition, East Cobb News reported. East Cobb News also noted in September that the revived language "isn't much different," that Chairwoman Lisa Cupid proposed the units to address housing affordability, and that the East Cobb Civic Association opposed them out of concern for the single-family character of neighborhoods. District 3 Commissioner JoAnn Birrell, who represents East Cobb, said before the Oct. 6 hearing that she did not support the proposal and cited enforcement and setback concerns, the East Cobb Beacon reported.

The outcome is open. The rest of this post looks at what the rule would mean if it passes, since that is the case buyers are pricing in.

A yes vote starts a one-year clock

The proposal now carries a delay. Commissioners added a change so that all ADU-related code amendments would take effect one year after the Board of Commissioners approves them, giving homeowners associations time to amend their policies, the MDJ reported.

When the rule takes effect, the ADU wouldn't be allowed by right. Each one would need a special land use permit approved by the Board of Commissioners. Jessica Guinn, Cobb's community development director, described the process to the MDJ:

"That's the only way it gets approved. It's done on a case-by-case basis. It goes through the public hearing process, the planning commissioners hear it, you make a recommendation to the Board of Commissioners (and) the Board of Commissioners … would ultimately vote on whether or not to approve the SLUP and also could attach stipulations to that."

If the vote passes on schedule, the earliest realistic path for one East Cobb lot looks like this:

1. Oct. 27, 2026: Board vote on the code amendment.
2. About one year later: the ADU provisions take effect under the one-year delay added to the proposal.
3. After that: the owner files a special land use permit application. Cobb's 2025 schedule sets the application fee at $1,000, plus a $300 sign deposit that is refundable if the signs come back within 30 days of the final decision and a nonrefundable $15 fee per sign.
4. Roughly two months after filing: a Planning Commission hearing and then a Board hearing. In the county's 2025 example, an application filed in early March reaches both hearings in May, and the schedule allows for date changes and continuances.
5. Then: design, permitting and construction, with whatever stipulations the Board attaches.

The fee and timeline above come from Cobb's 2025 schedule. A 2026 version may differ. On any reading, a cottage you hope to build behind a house you close on this winter is at least a two-year project, and every step needs a vote to go your way.

The rules shape who the unit is for

The draft code text is specific. An ADU could be no larger than 850 square feet or half the main home's gross square footage. It would be limited to one story and to the rear yard, would follow the main home's side and rear setbacks, and would count toward the lot's impervious-surface limit. Each lot could have one, and it would need at least one off-street parking space. It would also have to be connected to the main structure's utility meters. Short-term rentals would be barred, and the owner would have to live in either the main house or the ADU.

Taken together, those terms describe a unit for someone in the household's orbit. Cobb's explainer gives the examples of a family member, a caregiver or another household member. A shared meter means one utility account for both structures. The owner-occupancy rule means the lot can't become two rentals. Parking stays capped as well. Guinn told the MDJ that the maximum number of vehicles parked outside a lot stays the same "whether there's an ADU on the property or not." Today that limit is tied to home size at one vehicle per 390 square feet of living space. A separate proposal in the same package would raise the cap on vehicles parked outside a garage or carport from four to five in districts including R-15, R-20, R-30 and RA-5.

The size math also favors larger homes. On a 2,400-square-foot house, half the main home is 1,200 square feet, so the 850-square-foot cap applies. On a 1,400-square-foot ranch, the limit drops to 700 square feet. Setbacks and impervious-surface limits may shrink either figure further on a particular lot.

The HOA question sits outside the county's reach

This is where East Cobb differs from much of the county. The draft requires the property owner to sign an affidavit stating that the ADU doesn't conflict with "any applicable covenants, conditions, deed restrictions, or bylaws." County staff told the MDJ that the county can't legally enforce private covenants.

The county ordinance, then, doesn't override a subdivision's declaration. If a community's covenants restrict outbuildings or second dwellings, a county ADU permit doesn't change that. The one-year delay exists to give associations time to consider their policies, and associations could change their rules in either direction. In an HOA community, a buyer's practical question is what the recorded covenants allow, along with any amendments the association adopts during that year.

What the code already allows today

Without any vote, Cobb already permits attached accessory living space that uses the main home's entrance, the MDJ reported. The amendment would add detached units. East Cobb News has reported that permitted in-law suites and basement conversions are available under the current code. The amendment packet's residential-district text also covers habitable accessory buildings. It says they must connect to the main structure through a fully enclosed, heated and cooled hallway and sit within 25 feet of it.

For buyers, this changes how to read a listing. A finished terrace level with its own bath, or a main-level suite off the garage, is usable the day you move in. A big flat backyard offers, at most, the chance to apply for a future hearing. A "potential guest cottage" line in a listing describes a proposal that hasn't passed. Permit history and the county's records on how an existing suite was approved can tell you more than square footage alone.

How the City of Marietta handles the same idea

Buyers often compare East Cobb with addresses inside Marietta city limits, and the MDJ noted that Acworth, Mableton, Marietta and Powder Springs already allow ADUs. Marietta's approach is different in several ways.

Sources: Cobb's draft Chapter 134 amendments and Marietta's district codes for R-1, R-2, R-3 and R-4.

Marietta defines an ADU as a secondary independent dwelling on the same lot as a detached single-family home, attached or detached, located behind the main structure. Approval is simpler there, but the lot-area requirement rules out many smaller lots, and the ban on paying guests or tenants is broader than Cobb's draft, which names short-term rentals specifically and requires the owner to live in one of the two units. The Cobb draft text doesn't address long-term tenants directly.

Short answers for buyers

If the vote passes, does every East Cobb lot qualify? No. Each unit would still need a special land use permit, would have to meet the lot's setbacks and impervious-surface limits, and would require the owner's affidavit that no covenant conflicts with it.

If the vote fails, what changes? Nothing changes for the attached in-law space the current code allows.

Where can I read the actual text? Cobb posts the hearing schedule and the full proposed amendments on its code amendments page.

If you're weighing East Cobb homes partly on the possibility of accessory living space, Roxanne Sellers can help you sort listings by the in-law space that's usable now and pull permit history and HOA covenants before you write an offer. Let's Connect: Schedule a Consultation.

This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.