Established in 1981, D.R. Nelson and Associates is a general contracting company that provides energy-efficient construction solutions for residential and commercial properties. It has built more than 100,000 homes throughout the United States. The company specializes in the areas of tax credit compliance, compliance documentation and manual calculations. The company additionally specializes in the installation of fire-resistant rated wall and duct sealing. It offers room balance testing, duct blasting, plan analysis , project management, lighting, ventilation calculation and consulting services. The company s clients include General Motors, Ford, Chrysler, Dow, Westinghouse, IBM, Cray Computers, Ameritech, Nextel, CellularOne, MCI and the Department of Defense. D.R. Nelson and Associates is located in Lake Orion, Mich.