A constructability review is a systematic evaluation of architectural drawings by an experienced contractor to identify elements that would be difficult, expensive, or impossible to build as drawn — and to propose alternatives. A constructability review covers: dimensional conflicts between A/S/MEP drawings (a beam in the ceiling that conflicts with a duct in the same location); details specifying materials not available in the local market; space conflicts where designed dimensions don’t accommodate code-required clearances; sequencing conflicts between trades; and design decisions that add high cost relative to alternatives achieving the same design intent. Constructability reviews are most valuable at the DD phase — after major design decisions are made but before full CD investment. A constructability issue found at DD costs hours of design revision; found after CDs, it costs days; found during construction, it generates a change order.