Our History

Setting Standards. Exceeding Expectations Since 1934

1930s – 1940s

In 1934, William Donovan starts a construction business focusing on the coal industry. They developed new methods of constructing coal handling systems to meet the high demand caused by WWII.

1950s – 1970s

The company expands into Public Utility and Industrial Power Plants.


Bud Greenwald’s company buys Donovan Engineering & Construction Co., Inc., and gives the reigns to Roy Greenwald and Brian Walsh, who move the business to Brookline, New Hampshire.


Donovan Engineering & Construction Co., Inc., a regional leader in power plant and heavy industrial construction, purchases its first orbital welder. The company develops the Standard Operating Procedures for the biotech industry that have now been adopted by almost every firm in the industry.


Donovan Engineering & Construction Co., Inc., formally changes its name to DECCO. DECCO earns numerous national awards of merit for building micro-electronic and biotech industries throughout New England.  Engineering News Record (ENR) lists DECCO as one of the largest open-shop mechanical contractors in the Northeast.


DECCO continues to incorporate innovative tools and concepts to perfect our craft including utilizing pre-fabrication and modular methods, Integrated Project Delivery (IPD), Lean construction principles and Building Information Modeling (BIM).


DECCO launches new website!


DECCO Earns ISPE Facility of the Year Award for Facility Integration for Pfizer’s Building E Andover Clinical Manufacturing Facility


DECCO dedicates Craft Training Center “The Tim Barton Center for Craft Excellence” in memory of DECCO partner, Tim Barton, who passed away unexpectedly in June 2020. “The Barton” focuses on the advancement of careers in the trades and construction.


A new Core Value is added. In 2020 our Core Values were put to the test during a pandemic. Our Core Values guided us through some of the most uncertain times in our Country’s history. During this time, it became evident that we would formally adopt a fifth Core Value “Servant Leadership: In Order to Lead, We Must First Serve”.



DECCO celebrates the opening of its new 20,000 sf Corporate Headquarters in Nashua, NH and the expansion of the existing Brookline, NH facility to house DECCOFab and The Tim Barton Center for Craft Excellence Training Center.



DECCO achieves Accredited Quality Contractor credential from Associated Builders & Contractors. Only 229 of the nation’s elite contractors earn this designation.


DECCO Inc Critical Equipment Handling Service


DECCO announces new Critical Equipment Handling Services offering professional rigging services of vital equipment.

DECCO, Inc. Earns Great Place to Work Certification™


DECCO earns Great Place to Work Certification.  The prestigious award is based entirely on feedback from employee-partners.

DECCO Clean Utilities Service Program