Avesta Housing started building a 28-unit senior apartment project this week on Young Street in South Berwick that will help address a growing shortage of affordable housing for older Mainers.

Three apartments will be designed for people with mobility issues and two will be designed for people who have vision or hearing impairments, according to Avesta, a nonprofit housing development and management company in Portland. All apartments in the three-story building will be adaptable to promote aging in place, which is something most seniors want, according to AARP surveys.

“As people get older, it can get harder to stay in their homes,” Mindy Woerter, Avesta’s spokeswoman, said Wednesday. “We want to accommodate them and make their homes safe and comfortable as long as possible.”

House Speaker Mark Eves, D-North Berwick, praised the project as a model for other communities as he prepares to submit legislation early next year for a $65 million general obligation bond to build 1,000 units of affordable senior housing across the state.

“Our KeepME Home plan includes a bond designed to help seniors live independently longer,” Eves said in a news release. “We will be watching the Young Street project closely to see how to best model our bond proposal.”

The proposed borrowing would help address a statewide need for 8,000 additional senior housing units recently tallied by the Maine State Housing Authority.

Maine is the oldest state in the nation, with 18,250 people turning 65 each year, according to AARP. Seniors in the South Berwick area, in particular, can wait as long as four years for an opening in existing senior housing, Avesta reported.

The $6 million Young Street project is funded by low-income housing tax credits and other financing through Boston Capital, Maine State Housing Authority, NeighborWorks, Bank of Boston and Bangor Savings Bank.

Young Street Apartments will serve people age 55 and older and households earning 50 percent to 60 percent of area median income, which is about $23,000 to $40,000 per year, depending on household size. Monthly rental fees will range from $760 to $1,100, including utilities.

The Young Street project resulted from a collaboration between Avesta and South Berwick officials who wanted to convert an underused downtown parcel into a community asset. The project is in the town center – next to the public library, an elementary school, retail shops and a vibrant residential neighborhood – where town officials hope it will promote future downtown development.

Designed by Lassel Architects, the project will be highly energy efficient, including solar panels that will provide 20 percent of the building’s energy. Avesta and its partners will offer support services on site to help seniors with health and financial concerns, as well as technology to allow in-home conferencing with health care providers.

Rep. Eves’ KeepME Home initiative calls for additional legislation that would increase property tax credits for seniors who might otherwise lose their homes and boost Medicaid reimbursement rates for home care workers that have been stagnant for a decade.