semiprefab

Semiprefab is a construction approach in which portions of a building are manufactured off-site in a controlled factory environment and then transported to the project site for assembly or integration with remaining on-site work. It sits between traditional on-site construction and full modular or prefab systems, offering some factory-produced components while leaving room for customization and additional work on site.

Typical components include wall panels, floor and roof assemblies, stair sections, and MEP risers that may arrive pre-installed. Structural elements can be concrete panels, timber panels, or steel frames. Finishes, fixtures, and some mechanical-electrical-plumbing systems may be installed in factory or completed on site depending on project needs.

Benefits include shorter construction schedules, enhanced quality control, reduced material waste, improved safety on site, and fewer weather-related delays. Limitations involve higher upfront design and production coordination costs, transportation and handling constraints, and potential limits on design flexibility or need for on-site customization to accommodate site conditions.

Applications encompass residential and commercial buildings, multi-family housing, schools, healthcare facilities, and retrofit projects where rapid construction is beneficial. The term semi-prefab is used in markets that emphasize panelized construction and hybrid systems, and it often overlaps with, but is distinct from, true modular or volumetric prefabrication.

See also: prefabrication, modular construction, panelized construction, cross-laminated timber, structural insulated panels.