The survey was conducted with participating firms in July and August, 2018, and augmented by publicly available information. The survey requested information on firms’ development projects completed in the past 18 months and current on-the-boards development projects within New York, New Jersey, Long Island, and Westchester County only. The overall ranking, based on all applicable information available at the time, as interpreted by Interior Design, is an evaluation of the top 50 firms based on their total square footage of development projects completed in the past 18 months combined with ones the firms are currently working on. The data was compiled and analyzed by the Interior Design market research staff in New York, led by Wing Leung, research director.