The Company has its origins in Jamaica Water Projects Inc. (subsequently known as JWP Inc.), a company established in 1966 which emerged from Chapter 11 and was restructured and established in its present form as a contractor with electrical & mechanical contracting as its core activity (hence EMCOR) in 1994.
One of the first major acquisitions it made was Baltimore-based Poole & Kent in 1999.
It increased its involvement in facilities management when it bought Siemens's facilities management in 2003.
In July 2007, EMCOR acquired a pair of California HVAC services providers: Air Systems Inc, based in San Jose, and Fuller Air, based in San Diego.
In January 2008 EMCOR announced the release of EMCOR360, a facilities management product powered by utiliVisor software. EMCOR360 collects energy data directly from a facility's HVAC systems to determine less than optimal systems operations. EMCOR360 Certified Energy Managers then make recommendations to the facility's operating engineers to improve system performance and conserve energy.