Our History


Western Allied Corporation was founded as a Heating, Ventilating and Air Conditioning contractor in December 1960 by Pat Mattson, Hans Sommer, and Harold Waterman and was located in Santa Fe Springs, California.  An office was established in Northern California in 1972 in Belmont, California and moved to our current location in Menlo Park in 1977.

Western Allied Service Company of Northern California was established in 1973 to perform the service and maintenance of the HVAC systems designed and installed by Western Allied Corporation. Western Allied Service Company of Southern California, originally a division of Western Allied Corporation, was spun off as a separate company in November of 1976.

In 2003, the owners of Western Allied made a decision to reorganize the company into Northern and Southern Divisions. A new company, Western Allied Mechanical, was formed to operate in the Northern California area. This company consisted of the original Western Allied Northern California construction division, merged with the service division to form a full service HVAC contracting firm specializing in design/build projects.

In 2005, Western Allied Mechanical added another building adjacent to its existing facility to accommodate its growth in Northern California. In 2013, we moved our sheet metal and piping shops from the back of our current buildings to a new shop around the corner.  This shop allows for more growth in both prefabrication piping and duct systems as well as the fabrication of our new Kool and Therma duct lines.

Western Allied Mechanical Inc., continues to serve the Northern California area and provide high quality, energy efficient projects with an emphasis in US Green Building Council (LEED) projects, life science projects, and high efficiency office complexes.  We are supported by a Service Division with over thirty technicians available for 24/7 HVAC services.  We specialize in difficult retrofit and critical environment projects because we understand that a customer needs their air conditioning to always work.