When John Brennan III was 7 years old, he was involved in an automobile accident that left him handicapped. Despite the challenges created by the accident, Brennan went on to graduate from Stanford University in 1985 and Marquette Law School in 1991. After practicing law for several years, in 1994 he went to work for the family mechanical contracting business, JM Brennan.
In 1997, Brennan and his brother, Matt Brennan, purchased JM Brennan when the company had only 35 employees and performed $8 million in revenue. Over the years, the brothers have grown JM Brennan to more than 400 employees and $110 million in revenue, making them the largest Milwaukee-area mechanical contractor.
“I enjoy working with people on solving problems,” John Brennan said. “Problems aren’t always a bad thing. Often it is working with like-minded people to find good solutions that work for everyone involved, whether that be an owner, fellow contractor, vendors or employees, the construction field provides numerous opportunities to work out good solutions that benefit the whole team.”
JM Brennan is based in Milwaukee and serves all of southeastern Wisconsin. This year marks the company’s 90th year in business. Its history traces back to the Brennan’s grandfather, John M. Brennan Sr., who emigrated from Ireland and to start the business at the height of the Great Depression.
John M. Brennan Sr. served the Milwaukee community for more than 30 years. His son, John M. Brennan Jr., expanded the company’s capability and services over the next 35 years, until his own sons, John and Matt Brennan, took over the company.
JM Brennan has grown from a small plumbing company to providing design, construction and service of HVAC, building controls, plumbing, process piping, fire protection, fire alarm and underground utilities.
Outside of work, Brennan is the proud father of four adopted daughters and married to his high school sweetheart.
“John Brennan is an outstanding example of the construction industry,” his brother, Matt, said.