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About Us

We are a mechanical engineering firm serving architects and building owners in New Hampshire, Vermont, and Western Massachusetts. The company was founded in 1982, and since owner Roy Swain joined in 1995, we have designed heating, ventilating, air conditioning, and plumbing systems for more than four million square feet of commercial and institutional buildings, including more than 100 schools. We do not provide engineering services for single family residences.

Our mission is to design sensible, energy efficient and maintainable mechanical systems. Kohler & Lewis is a perfect choice for any project involving energy efficiency, air-source heat pump heating/cooling systems, biomass heating systems, or evaluations of existing facilities. For Electrical and Fire Protection engineering, we collaborate with a number of excellent Electrical and Fire Protection Engineers and are happy to help you form a consultant team to meet your needs.

Kohler & Lewis has received many awards for our designs. These include the ASHRAE New Technology Awards, Northeast Green Building Awards, and New Hampshire Preservation Alliance Awards. We have been the mechanical engineers for ten LEED buildings, and three Living Building Challenge projects, whose goal is to promote “the most advanced measure of sustainability in the built environment possible today”.  

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Service Area


Kohler & Lewis serves New Hampshire and Vermont, as well as western Massachusetts.