Capitol Engineering Company was founded in Cambridge in 1937 by Clarence H. Chaisson, P.E. Clarence, MIT trained as a naval architect and marine engineer, started Capitol for the design and construction of air conditioning, ventilation and heating systems for industrial, commercial, and institutional clients.

Clarence and Capitol specifically targeted providing air conditioning for the many movie theaters in the region. The introduction of safe, stable freon refrigerants opened up a whole new world of opportunities and soon both Clarence and Capitol became well known for their many air conditioning installation in theaters throughout New England.

In 1953, upon his graduation from the University of Maine in mechanical engineering, William T. Chaisson joined his father at Capitol Engineering. Together, Bill and Clarence were designing, fabricating, and installing innovative air conditioning systems before the rest of the industry. These systems included custom designed and fabricated glycol cooled computer room air conditioners, custom built drying ovens for manufacturers, and the development of custom prewired control panels for HVAC systems.

In 1972 the company moved its offices from Cambridge to Newton. When Clarence passed away in 1973 Bill assumed the leadership of the company. Bill continued to run Capitol Engineering and also took part in the industry as a whole. Bill's credentials include being the national director (2 terms) for ACCA, past president of Boston chapter of ASHRAE (of which he is a life member), past president of ARC of Boston, member of duct design committee for SMACNA, member of AEE, member of ACGIH, member of Newton Design Review committee, etc.

Currently Capitol Engineering's offices are located in Newton, MA. Bill and John continue to lead the company into the future. The company continues to strive in its pursuit to provide soundly engineered and installed HVAC systems while staying current with technology and trends, thanks to the talented people who are Capitol Engineering Company.

William T. Chaisson


Bill joined Capitol Engineering in 1953 with his father Clarence who started the company. Bill assumed leadership and ownership of the company in 1973 after Clarence passed away and has continued to lead the company and is currently the CEO. Aside from being a registered professional engineer (P.E.), Bill's many accolades in the industry include national director for ACCA, past president of Boston Chapter of ASHRAE, past president of ARC of Boston, and serving on several design committees. Bill is a life member of ASHRAE, and current member of AEE and ACGIH.

We are sorry to report that Bill passed away in February 2016 and will be greatly missed.

John G. Frugard


John started with Capitol Engineering Company in 1989 as a design engineer and has since worked his way up to President. John has a bachelor’s degree from Northeastern University and is a certified energy manager and LEED accredited professional. John also holds memberships with ASHRAE, AEE, and NFPA.

Barbara Altman


Barbara joined Capitol Engineering in 1980 in the accounts receivable department. In 1984 she left the company to pursue other interests and start a family. She returned to Capitol in 1991 again in the accounting department only to work her way up to the current position of Office Manager. Barbara oversees all of the accounting responsibilities as well as taking and dispatching service calls.If you have called the office, you were most likely greeted by Barbara on the phone.

Margaret Chaisson


David joined Capitol Engineering in April of 2019 and brings with him extensive experience in the HVAC and Electrical fields. Most of David's previous experience has been in project management but he enjoys working on the design side as well. David has a BS in Mechancial Engineering from Wentworth in Boston and is a Navy veteran.



Dan joined Capitol Engineering in May 2018 as a Design Engineer. Dan's responsibilities include load calculations, preparation of CAD Drawings, system designs, project management assistance and preparation of O&M manuals for our many projects. Dan has a Mechanical Engineering degree from the University of Hartford and is an EIT.