AMHERST — Members of the Amherst Municipal Affordable Housing Trust are recommending that a developer proposing a mixed-use building at 45-55 South Pleasant St. be allowed to donate more than $1 million to the trust fund instead of setting aside three of the 22 new apartments for low- and moderate-income families.

The trust voted unanimously at its March 14 meeting to recommend that the Planning Board, which began taking up the project’s site plans Wednesday., approve a “payment in lieu” special permit option for the project, while also examining whether the $1.1 million being proposed as a donation is sufficient.

“I just think this is actually a rare and wonderful opportunity that I kind of hope we decide to take,” said Carol Lewis, who co-chairs the trust.

If the payment in lieu permit is approved, it would mean all 22 apartments in the five-story building can be rented at market rate when the building opens, rather than having a handful restricted to households earning no more than 80% of the area median income.

The project is proposed by South Pleasant Street LLC, whose principal is Amherst developer Barry Roberts.

Gabrielle Gould, a consultant for Roberts, said the payment in lieu permit could create an endowment of sorts to help with the trust’s strategic mission. Gould said Roberts is partnering with former Hastings owners Mary Louise Broll and Sharon Povinelli on the development, which would include demolishing an “ell” at the rear of the 45 South Pleasant St. building along with the wood frame building at 55 South Pleasant.

“They see this as an opportunity to offer the trust a very real amount of funds to use at your discretion, an endowment of sorts to help with the strategic planning and mission of your trust,” Gould said.

Gould explained that 14 of 15 affordable apartments in the Amherst Business Improvement District, which she formerly oversaw as its executive director, are not currently leased, and that property owners are having challenges getting tenants into them. Gould said Roberts is already planning to provide 11 affordable apartments in a development at 422 Amity St., the former site of Rafter’s, with better parking and better access to a grocery store than is offered at the downtown site.

Senior Planner Nate Malloy said the town’s inclusionary bylaw allows other options besides including affordable units in a development, including providing the affordable units off-site within the same zoning district or within 500 feet of the property. Malloy said the idea of the payment in lieu permit was to cover development costs for each unit not included in a project.

The calculation for each unit is based on the $93,700 median family income for Amherst and multiplying that by four, meaning $374,800 would need to be paid by Roberts for each unit.

A memo from Malloy and Greg Richane, the town’s housing coordinator, explains that the mixed-use project includes four one-bedroom units, four two-bedroom units, five three-bedroom units and nine four-bedroom units. Negotiations for affordable units would likely yield one one-bedroom, one two-bedroom, and one three- or four-bedroom apartment as the affordable units.

Trust member Rob Crowner, who was on the Planning Board when the bylaw was developed, said it was important to have conversations about money going to help people transitioning from renting apartments to owning their own homes.

“I really like the idea of using the money to make homes right off the main streets downtown affordable for somebody,” Crowner said.

Trust member Gaston de los Reyes said the seed capital hinges on the trust prioritizing homeownership as part of its work plan.

Town Manager Paul Bockelman, who also sits on the trust, said he likes the idea of seeding the trust, though its precise work is not defined.

Community Preservation Act money has typically been the source of funding for the trust, so a significant payment from a developer would be a new source.

“This is the first time I’ve seen money that isn’t CPA,” Lewis said.