SOUTH HADLEY — Frustration boiled over at last week’s Municipal Light Board meeting as residents objected to the board’s decision to move forward with a proposed $37.5 million South Hadley Electric Lighting Department headquarters despite voters disapproval.

“I voted no on the nonbinding question,” said Cathy Allen, referring to a nonbinding question at the town election this spring. “And I would expect that people who represent me would honor the voters. I see that this is not happening here.”

The concerns did not sway the Municipal Light Board at the May 29 meeting. By the end of the discussion, members voted 4-1 to authorize General Manager Sean Fitzgerald to follow through on a purchase-and-sale agreement for 11 acres on Old Lyman Road next to Big Y grocery store.

The four in favor of the purchase reaffirmed the liabilities associated with the headquarters in South Hadley Falls and their duty to protect long-term electric reliability for the town.

“The current building is inadequate in every way,” Municipal Light Board Commissioner Paul Dabosh said. “In terms of space, in terms of safety, in terms of stability, everything about the building is wrong.”

Ron Coutu, who cast the dissenting vote and led the petition to put the nonbinding question on the ballot in April, vowed not to support any expenditures for the new headquarters plan. About 4,000 people voted against the project.

“If we didn’t care about their opinion, we shouldn’t do public forums.” Coutu said. “If we didn’t want to know what they thought, we shouldn’t have done a Know Your Town.”

Arguments briefly broke out a couple times between attendees and Municipal Light Board members before Chair John Hine regained order. Residents repeatedly expressed feeling disappointment, disgust and disregard that their voices are going unheard. New Select Board member Kevin Hennessey, who won a seat on the board in April, warned the voters would retaliate.

“There is a lot of sentiment out there against the board,” he said. “You really need to think about the voters. The voters are tired of the same old people in the same positions.”

One resident, John Howard, said this handful of voices do not speak for the entire town. Dabosh noted that voter turnout was 30%, which is not a full picture of ratepayers. Commercial and industrial properties make up 40% of SHELD revenue, but owners cannot vote.

“These board members have studied this, and four out of five of them, which I think is a pretty good rate, say it’s important,” Howard aid.

SHELD has been looking for a new headquarters to replace the 1958 building for over a decade. The current structure is “grossly inadequate” to modern staffing and space needs, Fitzgerald said. The location in South Hadley Falls is also susceptible to flooding.

The Municipal Light Board has surveyed several potential properties for the new headquarters, but the best and cheapest option is next to Big Y on Willimansett Street. The one-story building will include 10,000 square feet of office space and amenities for electrical crews, 11,500 square feet of garage space and 9,500 square feet for warehouse storage.

“It is not an enormous building. It is not. All three architects have said this is a lean building for a utility of our size,” Fitzgerald said.

The building was designed for future growth of both electric and Fiberspring, the broadband internet service the utility operates. Fiberspring was contracted to design and build out fiber-optic internet cables in Longmeadow for $27 million, but the first vote for the project failed at Longmeadow’s Town Meeting.