Gary Hennings - Principal

Gary is the co-founder of H&M Mechanical Group and Principal-in-Charge of the company’s engineering, construction administration, and heating, ventilating, and air conditioning departments.   His expertise includes the design of HVAC systems for office and retail buildings, hospitals, clean rooms, new and renovated fire stations, airports, libraries, recreational buildings, schools, and a myriad of others. With thirty-eight years of engineering experience, he has seen changes in the industry and steers the company appropriately.
Gary was past president of the Northern Chapter of ASHRAE and continues to be an active member.
Gary occupies his time away from the office by walking the trails around the San Francisco Bay Area or on the golf course.


California Polytechnic State University, San Luis Obispo
Bachelor of Science in Environmental Engineering, 1976
Golden Gate University, San Francisco
Master in Business Administration, 1988


P.E. California Lic #20245
P.E. Nevada Lic #5535
P.E.Washington Lic #30617


LEED Accredited Professional, 2006

Professional Organizations

American Society of Heating Refrigerating and Air Conditioning Engineers (ASHRAE)


8517 Earhart Road, Suite 230
Oakland, California 94621
(510) 569-2000 Ext 1