Hamilton, Massachusetts, Makes History with the State’s First Historic Net-Zero Town Hall
The town of Hamilton, Massachusetts, located north of Boston, has a long history. First settled in 1638 and incorporated in 1793, old stone walls, picturesque farms, and historic treasures weave throughout the community.
One such landmark is Hamilton Town Hall, a Colonial Revival structure built in 1897 by Salem builders Pitman & Brown and dedicated on February 22, 1898. Listed on the National Register of Historic Places and anchoring Hamilton's Historic District, the building has been the heart of local government for more than 125 years.
Now, it's making history again. In September 2026, Hamilton Town Hall officially became the first historic town hall in Massachusetts to achieve net-zero energy status. The structure has eliminated its on-site carbon emissions while remaining a fully functional, historic landmark.
A Project Years in the Making
The road to this milestone was not straightforward. Town officials had long wanted to make critical upgrades, such as ADA improvements, structural strengthening, and interior reconfigurations. However, voters did not approve an earlier proposal to do just that.
When the town revisited the project, Energy Systems Group (ESG) brought a new angle to the table: what if the renovation did more than update the building? What if it transformed the building into a net-zero energy facility? This approach resonated with leaders and residents alike.
In September 2024, voters approved a $10.5 million comprehensive package of improvements. The energy components, totaling about $1.38 million, were carved out and awarded to ESG through Massachusetts' Chapter 25A program, which provides a streamlined procurement process using prequalified vendors like ESG.
Innovative Solutions for a Historic Building
Working on a 128-year-old building in an active historic district requires creative problem-solving. When ESG evaluated options for achieving net zero, the team analyzed system performance, the building’s age and status, available grants and rebates, and the community’s goals. Based on these criteria, the team recommended a solar photovoltaic array and a ground source heat pump system.
The next challenge was how to best install these systems while respecting the building’s character. ESG's team found the answers next door: a garage owned by the Hamilton Department of Public Works (DPW) located behind the Town Hall and out of sight of the main road.
ESG installed a 36-kilowatt solar array on the DPW garage roof and ran lines underground to the town hall, keeping the building's exterior completely free of visible solar equipment. The DPW parking lot provided the space needed for the ground source heat pump system's two 900-foot standing column wells. Drilled into the lot and capped at the surface, the wells tap into groundwater that maintains a constant 55-degree temperature year-round to heat and cool the building.
A Better Building for the People Who Use It
The energy systems do more than reduce the town's utility bills. They make the building more comfortable and functional for staff and visitors.
The geothermal heat pump system, paired with an energy recovery ventilation system, maintains consistent indoor temperatures without drawing on the grid or relying on natural gas, which has been removed from the building entirely. A web-based building management system gives town staff real-time control over all building systems, making it easier to manage the facility and respond to issues quickly. New LED fixtures have improved lighting quality, which is linked to enhanced productivity, as well as energy efficiency.
Taken together, the upgrades are projected to save 62,080 kilowatt-hours of electricity and 6,680 therms of natural gas annually, translating to roughly $26,000 in energy savings each year and a reduction of 62.7 metric tons of CO2 emissions.
Funding That Works for the Community
The project was structured as an Energy Savings Performance Contract (ESPC), meaning future energy savings will help fund the infrastructure investment. On top of that, ESG identified and secured nearly $900,000 in grants and rebates. Over the contract's 20-year term, the performance guarantee projects $868,000 in total savings.
“Bringing in ESG as our dedicated energy partner changed what was possible for this project,” said Joe Domelowicz, Town Manager. “They did the legwork to identify every available grant, rebate, and incentive that a more generalized approach might have missed. The town got a premier, energy-efficient system, not just a code-compliant one, and the community didn't have to shoulder the full cost to get there."
From the street, Hamilton Town Hall looks exactly as it always has. But underneath, there are fully modernized systems that keep the building up and running. Hamilton didn't have to choose between honoring its past and investing in its future. With the right energy partner and creative solutions, it got both.
