BIDDEFORD — Last Wednesday the Planning Board voted unanimously in favor of a preliminary site plan to turn part of the Pepperell Mill Campus into 71 units of affordable senior housing.

The units would be built in Building 11 of the mill, which sits about 200 feet north of the corner of York and Laconia streets and about 150 feet west of the edge of the Saco River.

“This building, number 11, I would say is probably somewhat unknown for a lot of residents because it is tucked away into the campus, and unless you’re a Pepperell worker you might not be all that familiar with it,” Steve Bushey, a civil engineer with Massachusetts-based Fay, Spofford and Thorndike, said at the meeting. “By and large, it’s not really a face of the Pepperell Campus.”

Kevin Bunker, one of the founding principals of Portland-based Developers Collaborative, which is the company spearheading the project, also spoke to Planning Board members, discussing the need for affordable senior housing in the area, especially as members of the so-called Baby Boomer generation age into their late 50s and 60s.

“The only age-restricted affordable housing that’s out there is the Emery School, which I did several years ago. ”¦ We are seeing the need for senior housing really explode,” he said. “There’s a demand for these units that the marketplace quite frankly can’t meet because the marketplace can’t deliver the kind of quality that we can by taking advantage of the financing programs. The market demand is absolutely there.”

Bunker explained that Developers Collaborative will apply for tax credit financing for the project at some point in the fall, with the hope of finishing the project by the summer of 2016. As for who would be able to live in the rental units, Bunker said the target demographic is people who are 55 or older and earn about half of the area’s median income.

“Generally speaking, those rents are going to range from high (500s), low (600s) to mid (700s,) low (800s) ”“ basically, $500-800 dollars per month, so that generally serves people ”¦ making probably $25,000 to 37,000 a year,” he said. “They have to make enough money certainly to afford to pay their own rent. It’s not Section 8 housing.”

Bunker added that those who are interested in living in the units won’t be able to get on a waiting list until half to two-thirds of the construction is complete.

The project replaces the previously approved Laconia House project, which would have added 43 units of general-use, affordable housing to Building 19 of the Pepperell Mill Campus, Daniel Stevenson, the city’s economic and community development director, said in an email Sunday.

“This proposal will remove the original approval and replace (it) with senior housing in a different building,” he said.

— Staff Writer Angelo J. Verzoni can be contacted at 282-1535, ext. 329 or [email protected].