This proceeding, ""Preparing for Construction in the 21st Century"", consists of papers presented at the specialty conference Construction Congress '91 held in Cambridge, Massachusetts, April 13-16, 1991. It provides a forum for active practitioners who are involved in research and development to exchange ideas and present new information. This monograph covers such topics as temporary structures, the changing nature of project controls, computer-integrated design and construction, construction inspection services, underground construction, and technology innovation. These papers will help the engineer understand the changes gradually occurring within the construction industry.