Beau Parker, 22, of Hermon works with Sean Sweeney, 40, of Ellsworth (on stilts) buffing sheetrock at Washington Luxe apartments in Ellsworth on Wednesday. The owner of Washington Luxe proposes to build 61 more properties in Ellsworth.

An Ellsworth developer has announced plans to build two major projects, partly in response to Jackson Laboratory’s challenges in finding affordable housing for its workforce in Hancock County.

The developments proposed by Jonathan Bates of Stone Park Properties LLC would add 61 housing units to Ellsworth, and cost an estimated $9.3 million to build over the next 1 ½ years.

The proposed developments are part of a housing boomlet in Ellsworth, the county seat and service hub of Hancock County. As of Wednesday, Ellsworth has 61 units under review, 46 under construction and six units that have been issued permits since Jan. 1, Assistant City Planner Steve Fuller said.

The latest proposals include:

— The 45-unit Jefferson Luxe Townhouses complex proposed for Beechland Road, which will cost as much as $6 million to build;

— Denver Way Eco Homes, 16 single-family, two-bedroom housing units on Route 1A between Wittum Road and Penn Way that will cost about $3.3 million.

Within walking distance of Jackson Lab’s $200 million mice breeding center, Jefferson Luxe is intended as a direct response to Jackson statements in February that the organization’s biggest challenge is a housing shortage in Ellsworth and Mount Desert Island, Bates said.

“We are talking to Jackson Lab right now to see if they want to get involved,” Bates said Tuesday. “It all depends on their interest. They might say, ‘Hey, we want 30 units on retainer.’”

Bates isn’t seeking a partnership with Jackson, which has 1,400 workers in Bar Harbor and will eventually have as many as 350 at its Ellsworth vivarium. But he has met with Jackson Lab officials to make sure their employees are aware of his plans, Bates said.

None of the new units will likely eliminate the demand for new housing. The new housing is more likely to answer a demand pent-up in Hancock County since the crash of 2008-09, City Manager David Cole said.

“We need housing all across the board, from workforce housing to what he [Bates] calls luxury townhouses,” Cole said.

The Ellsworth Planning Board will do its first review of the Jefferson Luxe and Denver Way proposals on May 1 at 6:30 p.m., Fuller said.

Jefferson Luxe complements another Bates project, a $2.2 million, 24-apartment complex overlooking Union River. Called Washington Luxe, the two three-story buildings at 29 Washington St. should be open and fully occupied by June 1, said Bates, an Ellsworth resident who owns 56 commercial and residential properties in the city.

Both Jefferson and Washington are intended to be high-end, fully furnished apartments for young professionals, Bates said.

Denver Way is keyed to a different audience, baby boomers, Bates said.

If all goes well, construction on one of the projects will start this summer, with the second project starting next spring, Bates said.