Modulbygg

Modulbygg, or modular construction, is a method in which buildings are assembled from prefabricated modules manufactured off-site in a factory and transported to the construction site for on-site assembly. Each module is typically a self-contained room or series of rooms with integrated structural, mechanical, electrical and plumbing systems, enabling rapid installation once on site. Modules can be volumetric (three-dimensional) units or wall panels and other prefabricated elements that are combined to form the final building.

The fabrication process offers high quality control, time savings and reduced on-site disruption. After the modules are built, they are transported to the site, placed on a foundation, and joined using structural connections, with utilities connected to form a weather-tight building envelope. The approach supports multi-storey construction and can incorporate repetitive floor plans to achieve economies of scale.

Materials commonly used include timber (notably cross-laminated timber), steel frames and concrete. Timber modular construction is favored for lower embodied energy and fast erection, while concrete modules are used for strength and fire performance. Hybrid systems combining different materials are also common.

Applications span housing (including apartments and student housing), hotels, schools, healthcare facilities, offices and emergency or temporary housing. The method is popular in regions facing housing shortages or where rapid deployment is required.

Challenges include logistics of transporting large modules, erection constraints, and the need for careful upfront planning and coordination of services. Regulatory and certification processes vary by country, with growing adoption of factory production control, BIM-enabled design and standardized interfaces to improve integration and performance.