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 the needs of a project and the personal relationship formed with the client. His level of commitment spread to his employees and the company and what started with one employee has grown substantially to over 40 employees with an average tenure of 10 years or more.

Now celebrating over 40 years of success in the business, Hennessey Engineers, Inc. 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 two of his children, Joan E.Hennessey, CPA and John J. Hennessey, PE.

Hennessey’s approach to success is realizing that it is not the quantity of employees that make an outstanding organization, but rather the quality.


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

Hennessey Engineers strives to develop strong partnerships with our employees by establishing an atmosphere of communication, trust, team-work, and encouragement of professional development.

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


Here at Hennessey, we take pride in our small company size. 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 to the community 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.