CHARLOTTE, N.C. – Charlotte's planning staff is studying an idea that could block some new development in existing neighborhoods to protect their character.

It's a move that residents in some fast-changing Charlotte neighborhoods might welcome, but one that others worry could stymie affordable housing.

Called "neighborhood character overlay districts," the idea is still in the early stages. Planning staff presented the idea to Charlotte City Council's Transportation and Planning Committee last month.

"It's an interesting concept that would be new to our area," said Greg Phipps, chairman of the committee. Staff plans to study the proposal and figure out how to move forward within 90 days.

Phipps said a proposed "tiny house" development called Keyo Park, in the Coulwood area of west Charlotte, sparked interest in the character districts. Neighbors are concerned that the 500-square-foot houses would damage their property values.

By setting minimum lot sizes and other conditions, a new neighborhood character overlay district would prevent houses on lots below a certain size from being built in an area, preventing tiny houses and other unconventional developments.

Many neighborhood groups might jump at the opportunity to lock in the current look and feel of their area, and not worry about what's being built down the street. But Phipps said he and other council members worry about the potential for strong "not-in-my-backyard" backlash, especially because some developments, such as apartments, denser townhouse communities or affordable housing already tend to draw strong opposition.

"In discussing the concept, there were also some concerns about the potential impact of it," Phipps said. "It's heavily influenced by the existing homeowners. If you get a neighborhood that's basically against something, it wouldn't be too hard to use this tool as a way to keep different projects out of their neighborhood."

An overlay district is a set of special regulations about land use that applies to a certain area. Here's how the idea would work:

A neighborhood would be able to petition the City Council for a neighborhood character district if a majority of property owners endorsed the idea. The City Council would hold a hearing and vote on the plan, similar to the rezoning process in place now.

If an overlay district was adopted, it would regulate components of land use, such as the minimum width of a lot, the height of buildings, required size of side yards or driveways, and how far back houses are required to be set from the street.

Although it wouldn't regulate architectural design or dwelling size, such an overlay could effectively preclude tiny houses by mandating all lots be a certain width, such as 140 feet, for example. An overlay could also potentially preclude homeowners and developers from subdividing lots and building multiple houses there, a phenomenon that's angered neighbors in places such as Cotswold.

A handful of North Carolina cities allow neighborhood character overlay districts, including Greensboro, Durham and Raleigh. Bynum Walter, a senior planner with Raleigh, said the districts have been used sparingly, with about 20 total in the city. Two have been implemented in the past year, after about eight years in which no new districts were requested.

One reason the districts might not be more common is time. Walter said the process takes a year or more, with hearings and review by the City Council.

"Whenever you have a public process and you're talking about their property, it's good to move deliberately," she said. Many newer neighborhoods, those built from the 1970s on, are also governed by homeowners associations that can already regulate what gets built.

Neighborhood character overlay districts could face an uphill climb in Charlotte. Larken Egleston, another City Council member on the transportation and planning committee, said he's seen dense development on his street in Plaza Midwood, with six houses going on a lot formerly occupied by one.

But he's still skeptical.

"I am in favor of helping neighborhoods preserve their character, but it could easily be used to lock out things and people a neighborhood might deem undesirable," Egleston said.