Neighbors of ASML, which is undergoing a $100-million expansion at the facility on Danbury Road, are complaining to town officials about noise from the construction.

One neighbor, Rose Havron, spoke at a public forum for the first time in her life at a public hearing of the Planning and Zoning Commission June 11 to complain about the incessant banging of heavy machinery. She played an iPhone recording of the noise, which some said sounded like rocks being pounded.

“The noise level is intolerable,” Havron said, adding it starts early in the morning, and continues to about 5 p.m., five days a week. On Saturdays it goes for six hours instead of eight. She expressed concerns that if she tried to sell her home in this environment she would not get her price.

“It is horrendous,” said neighbor Rocky Delfino, who said he lives right behind the factory. He said there are other noises too, other than rock smashing.

The noise level of construction became a topic of concern at the meeting because ASML attorneys and engineers were there to apply for an increase in site coverage for their Design Enterprise zone, from 40% to 50%, to better accommodate the company’s growth. The expansion is expected to create 500 new engineering and manufacturing jobs.

The company also applied for construction of a 25,170-square-foot addition on the southwest corner of the existing facility at 77 Danbury Road, to be used as a truck loading dock center.

Planning and Zoning commissioners and staff assured the outraged neighbors that regulations on noise levels will be followed.

First Selectwoman Lynne Vanderslice, who attended the meeting to address the neighbors’ concerns, said she has calls in to management at ASML and is working on a solution.

She said there were similar concerns at Miller-Driscoll school when it was being built.

“Rose called my office last week, and I called the company’s director,” Vanderslice said. “ASML is a good member of the community and I’m sure we can work it out,” she said.

The expansion includes a 700-space parking garage on what was a former parking lot and office and manufacturing areas that will add more than 45,000 square feet of work space across three floors.

The hearing on the new ASML applications was continued to the next meeting June 25.