D.A. Sullivan & Sons, Inc. (DAS) is a mid-sized General Contracting, Construction Management, and Owner's Project Management firm based in Northampton, Massachusetts.Established in 1897, DAS has served all of New England, but primarily the western Massachusetts area for over 125 years. With annual sales of $45-50 million, DAS typically manages 15 projects a year. Well regarded in the construction industry, DAS maintains deeply rooted ties to the surrounding communities.