J.M. Brennan, Inc. is one of Milwaukee’s largest mechanical contractors. We perform HVAC and Plumbing construction, maintenance, and service for Commercial, Industrial, and Healthcare facilities throughout southeastern Wisconsin. We have complete in-house capabilities including engineering, design, BIM, and prefabrication. We have an 87 year history of performing successful projects completed on time and on budget. We continue to build on a tradition of quality, workmanship, and superior value.