Nilsson + Siden Associates, Inc. (N+SA) is a multidisciplinary architectural firm located in Salem, Massachusetts. Founded in 1981, N+SA provides architectural/planning services for commercial, institutional, medical, and municipal projects. Sample project types include university athletic, classroom and housing facilities, hospital facilities and master planning, medical offices, laboratories, branch banks, museum renovations and urban planning. We pride ourselves on the quality of service and attention to detail every project receives.