Sandy Springs may mandate affordable housing in large multifamily developments, a major policy change proposed in its new draft zoning code.

It would be the city’s first-ever affordable housing mandate, and is under consideration as skyrocketing rents and house prices displace residents and prevent public safety workers from living there. The policy is what is widely called “inclusionary zoning,” though Lee Einsweiler, the consultant drafting the new zoning code, said the city does not want to use that term, instead preferring “mixed income floor area.”

The proposed policy would require a certain amount of affordable housing, guaranteed for at least 30 years, in any new multifamily project – for sale or rental – of 20 units or more. The developer could build the affordable units into the project, the “primary and preferred” option; build them off-site somewhere else; or pay a “fee-in-lieu” of $3 per square foot, which would go into a trust fund to plan, subsidize or develop affordable housing.

The amount of affordable housing required would be a percentage of the project’s gross floor area, not a number of units. For on-site development, there are two options, one focused on middle-income affordability and one on lower-income affordability. In option one, 5 percent would go to housing affordable to those making less than 80 percent of the area median income, and 5 percent to those making less than 120 percent of AMI. In option two, 5 percent of the project would go to housing affordable to those making less than 50 percent of AMI.

If the developer takes the off-site option, 7.5 percent of the project must go to those making under 80 percent of AMI and another 7.5 percent to those making under 120 percent of AMI.

In addition, the draft code proposes a bonus system allowing multifamily developments to build higher in exchange for offering more affordable housing – both in terms of a higher percentage of floor area than required and in providing units for lower-income residents. The code does not define how good those affordable offerings must be to trigger the bonuses. Einsweiler said it would be up to the City Council to judge.

An earlier draft code proposed a limited affordable housing incentive – not a mandate – focused solely on middle-income housing and done only with a bonus system. The incentive used a unique and complicated formula. In public meetings, the idea was criticized as insufficient and confusing.

The new proposal is stricter, broader and more in line with national models. However, the two residents who commented about the proposal at a June 21 city Planning Commission meeting criticized it as still insufficient compared to the need. Pam Jones and Dr. Christine Bruno called for gathering better data on low-income residents and more research on national models of providing affordable housing.

Bruno, a Huntcliff resident who works in the Medical Center, called the affordable housing proposal an “oversimplification” that is “already inadequate.” She particularly criticized the option to pay a fee instead of actually building the affordable housing. That option, she said, “abdicates our power to design the community we want and have affordable housing.”

Jones, a Riverside resident, said she is worried about families being driven out by rising rents, and possible impacts on the school system as they are replaced by wealthier single people. She wanted more options from the “Next Ten,” the city’s nickname for its process of revising its land-use plan and zoning code.

“I’ve been reading the Next Ten, and it’s about pretty much everything but the people who were already living here,” Jones said.

An updated version of the zoning code is expected by July 10 and a City Council adoption on Aug. 1.