Grennan Construction is a trusted, family-owned exterior remodeling contractor based in Pontiac, Michigan, proudly serving Oakland County and the surrounding areas. Specializing in residential roofing, siding, and gutters, we deliver high-quality craftsmanship with honest, customer-first service. Unlike typical contractors, we take a consultative, education-based approach — guiding homeowners through every step of the remodeling process, from the initial inspection and estimate to the final project walk-through. Our goal is to help you make confident, informed decisions and ensure your home improvement project is done the right way, the first time.