The Eagan City Council this month approved zoning changes that officials hope will stop builders from putting “huge McMansions on tot lots” and result in more affordable homes instead.

City Planner Mike Ridley said the ordinance was designed to offer more varied housing styles at lower prices. “You don’t want to go shopping somewhere where they only have one product,” he said.

The updated zoning rules will restrict the footprint of a new house on smaller-sized lots to 2,000 square feet (including garage) or 20 percent of the 8,000-square-foot lot, whichever is less.

The zoning changes also call for homes to be set back 10 feet from the property line on each side. Owners of existing homes on smaller lots will need the city’s permission to build additions.

Ridley acknowledged that the new restrictions still allow for big houses — just not as large as those permitted on standard lots.

“We’re not talking tiny houses by any means,” he said.

The changes are intended to make up for the failings of a zoning category the city created more than 10 years ago. That ordinance allowed some single-family homes to be built on lots between one-fifth and one-sixth of an acre, which is smaller than the 12,000-square-foot lot size that Eagan usually requires.

The ordinance also was supposed to ensure that older homes sitting on smaller lots met current standards, and also allow houses to be clustered closer if a plot had features like wetlands that couldn’t be disturbed.

But it didn’t work, officials said. It resulted in builders constructing disproportionately large homes on smaller lots rather than the medium-sized homes the city had hoped for, said Council Member Paul Bakken.

“It’s no secret that I’ve hated this zoning category,” Bakken said, which according to him has been used only once “for the intended purposes in our ordinance. It’s always been used as a density grab.”

Eagan’s latest zoning change comes as many metro communities grapple with how to promote construction of less-costly housing.

“We’re in this massive discussion about affordability,” said David Siegel, executive director of the Builders Association of the Twin Cities.

Siegel said that many believe that new single-family homes built in the Twin Cities — which cost $417,000 on average — are more expensive than in the past because builders want to make more money. Wrong, he said.

“It’s because they can’t build a cheaper house,” he said, citing a limited land supply, infrastructure fees and the cost of meeting various building codes.

Siegel said that he hadn’t heard of another city making zoning changes for the reasons Eagan has cited. “We applaud the city for thinking creatively,” he said. “[But] if we think that zoning in and of itself is going to solve the affordability problem, it’s not.”

Council Member Gary Hansen acknowledged that it might be hard to find compliant builders.

“We’re going to be talking a lot less than $400,000, $500,000, $600,000 homes,” he said. “Our challenge will be finding developers who are willing to play by those rules.”