A prominent Southington developer is proposing a 27-unit age-restricted housing development in the town’s Plantsville section, a project based on a formula that he has built in Southington, Farmington and Plainville and will be pursuing in Watertown.

Mark Lovley’s new development along Marion Street will be a mix of three-bedroom houses ranging from 1,444 to 1,610 square feet, each with a two-car garage. The plan is to price 90 percent at market rates and reserve 10 percent as affordable housing.

“I’ve built about 100 of these with the same floor plan, two with 15 in Southington and one with 61 in Plainville. Everything is sold out, everyone is moved in,” said Lovley, principal in Southington-based Lovley Development.

The 27 stand-alone houses will be clustered on part of a roughly 14-acre property, leaving vastly more open space than a traditional subdivision of larger, more spread-out single-family homes would, according to Lovley Development’s application for a zone change.

Under current zoning, a developer could build 13 homes with significantly larger lots. The zone change would allow 27 homes laid out along a new dead-end street that would be built to run off Marion Avenue. Braemer Court would be a privately owned roadway maintained by a homeowners association, and near its end would branch off into two identical cul de sacs. Each would serve driveways for about five or six houses.

The market for relatively small but modern three-bedroom homes is largely retirees from Southington and nearby towns downsizing from a traditional house, as well as retirees who moved elsewhere but now want to return to Connecticut, he said.

Based on buyers for the 61-home Willow Brook complex on the Farmington and Plainville border, there’s a wide demand for age-restricted housing in the region, he said.

“About 25 percent are people moving back from out of state. We’ve had a lot of people coming back from Florida, the Carolinas, upstate New York, New Hampshire,” he said. “What happens is their kids are having children, so the grandparents want to come back and live here.”

The units are one-story with two full baths, and a master bedroom suite with walk-in closet. There is also a full basement; some buyers finish those to turn into an additional bedroom for visiting relatives, he said. Often, buyers use one of the two smaller first-floor guest bedrooms as a den or office.

Lovley said his staff has already begun a list of prospective buyers who have heard about the Marion Avenue proposal even before it has gone to a zoning hearing.

“These are people who just head and called in. Everybody says Southington needs more 55-and-up living,” he said.

Willow Brook advertised vaulted ceilings, gas fireplaces, granite kitchen counters with an island, and stainless appliances. Each home has a paved brick patio and front walk along with a covered front porch. Valenti built the project in partnership with Tony Valenti; together they are also developing the ambitious Steele Center mixed-use complex of apartments and businesses at the Berlin railroad station.

Floor plans for the Southington homes show an open living room, dining room and kitchen area, and Lovley noted that hallway spaces takes up just 32 feet.

“People ask how we can have three bedrooms and so much space; it’s because there’s no wasted space,” he said.

Lovley said a professional traffic study for his new Southington project concluded that building 27 age-restricted units would have only a tiny additional impact on traffic compared to putting in 13 standard single-family homes.

“A lot of people have only one car when they get to this time in their life, and 20 percent of our homes have a single person living there,” he said. “And about 30 to 35 percent go to Florida or another state in the winter.”

The homeowners association will handle snow plowing, mowing and landscaping, and weekly pickup of trash and recycling.

A key benefit to the town would be that age-restricted housing doesn’t run the risk of raising school enrollments, according to the company’s presentation. An age-restricted complex of 27 units would generate about $256,000 a year in taxes, have most services paid privately, and add no children to the schools, the company said. A 13-unit traditional subdivision would add $156,000 in tax revenue, require municipal services and likely add about 20 public school students at a yearly cost of more than $420,000, the company said.

Lovley Development will make a presentation to the planning and zoning commission in July. It already owns the property at 347, 349 and 389 Marion Ave. where it would build.

The company has built more than 1,400 homes in the region in the past 39 years, ranging from modest to luxury. It advertises that most of its new offerings are in the $400,000 to $800,000 range, but acknowledges that its highest end homes — such as the four-bedroom, 3,628-square-foot units at its Whispering Oaks traditional subdivision in Cheshire — have prices topping $1.2 million.