GBG.CONSTRUCTION G.B.G. Gold Building Group Services is a family-owned and operated business, specializing in managing single, multi family homes and condominiums in the Somerville and Cambridge areas. We understand how important it is to place your investment property in the hands of a company you can trust; we have over 20 years experience managing properties, you can be assured of our personal attention in the care of your tenants and property. We manage all day-to-day dealings with your tenants, including any maintenance needs.