42 Inspection services, namely, surveying and evaluation of roofs, walls, parking lots, pavement, building foundations, and exterior lighting; inspection services, namely, detection of leaks in steam distribution lines; inspection services, namely, detection of thermal energy loss from buildings and industrial plants; design services, namely, design of roofs, walls, parking lots, pavement, and exterior lighting installations; diagnostic services, namely, diagnosis of roofs, walls, parking lots, pavement, building foundations, and exterior lighting; engineering services for commercial roofing systems