As a family-owned and operated company servicing Oakland County and the surrounding areas, Grennan Construction has earned a reputation for honesty and integrity. Founded in 1998 by Fred and Phil Grennan, Grennan Construction takes great pride in providing what many people feel is the best customer service in the business. We will take the time to get to know you and what you want and need in a home improvement project – allowing us to offer the solution that is best suited for you.