Timothy L. Hennessey, P.E.
Founder of Hennessey Engineers
August 25, 1922 – February 15, 2010

Hennessey Engineers, Inc. was founded in 1971 by Timothy L. Hennessey. It was a long standing dream of his to transform the civil engineering industry and start his own firm. With his incredible passion and drive, the company was established as a civil engineering consulting firm and set out to respond to the needs of the Detroit Downriver area. Tim Hennessey had amazing passion and dedication to his projects and the personal relationship formed with clients. His level of commitment spread company-wide, and what started with one employee has grown substantially to over 50 employees with an average tenure of 10 years or more.

Now celebrating nearly 50 years of success in the business, Hennessey has expanded not only its services, but also its service area to much of Southeast Michigan. Hennessey is a privately owned corporation licensed to operate in the State of Michigan. Today the company is owned and operated by Joan E. Hennessey, CPA and John J. Hennessey, PE, two of Tim’s children.


Our mission is to be one of the most innovative and competitive firms in the engineering field.

Hennessey strives to develop strong relationships among employees by establishing an atmosphere of communication, trust, team-work, and the encouragement of professional development.

As a team, we work with our clients to manage the quality and efficiency of our projects, while maintaining responsibility to the environment.


Here at Hennessey, we believe it takes a strong personal relationship and attention to detail to guarantee a successful project. Our friendly atmosphere and close community enables flexibility and new opportunities within the workplace. With the size of our company, we prefer to be involved in every aspect of a project and it is with this personal and detailed approach that we stand out amongst the rest.

Hennessey is actively involved in the community attending numerous municipal functions as well as giving back through fundraisers and experiential learning events. We look to enrich our communities through the projects we design and the wisdom we can pass on to future generations.