A construction mockup is a full-scale physical sample of a building component (window unit, exterior wall section, finish detail, custom millwork) built on or near the project site so the owner, architect, and contractor can verify design intent and quality before committing to full-scale installation. Mockups are most common on high-end commercial and custom residential where finish quality matters and on technically complex assemblies (curtain walls, complex cladding, intricate millwork) where coordination errors are expensive at scale.
Mockups are typically required by specification, with acceptance by the architect documented in writing before full installation begins. Approved mockups serve as the quality benchmark for the rest of the work. Mockup costs are typically a separate line item in the bid.