J.M. Brennan Inc.
About
J.M. Brennan, Inc. is Wisconsin’s most trusted mechanical contractor, serving industrial, commercial, healthcare, and institutional clients throughout Southeastern Wisconsin since 1932. Headquartered in Milwaukee, the company provides single‑source mechanical solutions with full in‑house capabilities—from design and engineering to construction, installation, and 24/7 service.
With nearly a century of experience, J.M. Brennan specializes in HVAC systems, plumbing, process piping, industrial sheet metal, building controls, fire protection, site utilities, and electrical services. Their team of highly skilled tradespeople and technicians is known for craftsmanship, safety, and reliability on even the most complex projects.
Services Provided
HVAC
Plumbing
Electrical
Process Piping
Fire Alarm, Fire Sprinkler, Fire Extinguisher
Trenching & Underground Utilities
Industrial Sheetmetal & Custom Fabrication
Pre-Con/ Pre-Fab
Industries Served
Data & Technology
Energy
Industrial Manufacturing
Food Processing
Commercial
Healthcare
Education
Refrigeration
Oil, Gas & Chemical
