J.M. Brennan is a mechanical contractor dedicated to providing high performance HVAC, Building Controls, Plumbing, Process Piping, Industrial Sheet Metal, Fire Protection & Monitoring, Site Utilities and Electrical. We employ over 500 of the most highly skilled Pipe Fitters, Plumbers, Sheet Metal Workers, Sprinkler Fitters, Service Techs, Controls Techs, & Electricians. We provide engineering, sustainable design, and service 24/7. Our customers include industrial, commercial, and healthcare facilities throughout Southern Wisconsin including Milwaukee and Madison.