Our Services Include Design Build // Custom Homes // Additions // Renovations Kitchens // Bathrooms // Basements // Much more... Design Build, Custom Homes, Additions & Renovations For over 25 years, Monahan Building has been constructing custom homes and providing expert renovations throughout the Main Line and Suburban Philadelphia area. Founded in 1990 by Mike Monahan, we have established ourselves as premier builders grounded in integrity, quality and service. We have built some of the Main Line’s most aspirational homes and have made our mark with consistently excellent quality construction. Monahan Building has won the Best of...