AMHERST — Several North Amherst homeowners are requesting that their property taxes be reduced during and after construction of a large-scale, mixed-use development on Cowls Lane.

But the Board of Assessors, which received a March 1 letter signed by 10 residents at seven owner-occupied homes on Montague Road and Summer Street, couldn’t act on the plea because the North Square at Mill District, which would include 130 apartments and 22,000 square feet of commercial space, hasn’t yet broken ground.

“An assessment is reactive to a market, and there’s no market until it’s built,” said David Burgess, Amherst’s principal assessor. “We can’t react to something that’s not there.”

In the letter, the residents ask for “a reduction in property taxes to ameliorate the negative effects of the proposed development” during the building phase and the first year of occupancy.

“The quality of life, productivity and well being of long-time taxpayers in nearby residences will be negatively affected by this development,” the letter reads. “In contrast, the out-of-town and for-profit developer is receiving a 10-year, $2.8 million tax abatement approved by the Select Board.”

The letter cites two abutters to the project who put their homes on the market and failed to sell them, along with the anticipated increase in traffic, dust and dirt.

“I think what neighbors are feeling is this is totally inappropriate for this area of town,” said Paola Di Stefano, of 115 Montague Road.

The Zoning Board of Appeals last month issued a comprehensive permit under the state’s chapter 40B law to Beacon Communities Development, LLC of Boston to move forward with the $47.5 million project. The comprehensive permit allows the developer to skirt some of the town bylaws that limit density on a property. That decision is currently being challenged in Hampshire Superior Court by a Leverett resident who owns a Sunderland Road property.

Di Stefano said the letter was important to send because many neighbors feel they were not listened to or respected in their advocacy for reducing the size of the project. In addition, the time it will take to build is a concern.

“The prospect of living with that all day into the dinner hours for 18 months to two years is pretty appalling,” Di Stefano said.

Though the assessors can’t immediately reduce property taxes for residents in North Amherst, Burgess said when tax bills go out to property owners later this year they could appeal. But Burgess said the assessors would ask for substantive proof based on the market conditions.

Such neighborhood letters are unusual, Burgess said, though periodically similar cases are made about a project’s impact on home values. Burgess points to the extended municipal rebuilding of Pine Street in 2013 and 2014, which led to the creation of bumper stickers being sold that read “This Car Survived Pine Street” when the well-traveled road had its pavement removed for several weeks.

Even in that case, though, Burgess said there was no evidence of a decline in home values on Pine Street.

Scott Merzbach can be reached at smerzbach@gazettenet.com

Scott Merzbach is a reporter covering local government and school news in Amherst and Hadley, as well as Hatfield, Leverett, Pelham and Shutesbury. He can be reached at smerzbach@gazettenet.com or 413-585-5253.