[en] An objective of this program was to influence two key areas: inputs to plant design that can enhance constructability; and improvements in the construction process. The investigations, workshops, meetings, and studies focused the program topics toward these areas. This document, Volume IV is Enchancing Constructability through design. The report is arranged to produce sections on major issues in each subject. At the end of each section are significant conclusions divided as: recommendations--conclusions worthy of acceptance; considerations--conclusions that were not universally accepted in the discussions but should be taken into account; and cautions--conclusions that should be evaluated to avoid past problems