The modern way of constructing buildings is smart and effective. When you relocate part of the building process to a highly efficient factory, the construction times can be dramatically reduced.
Wall parts, floor components, roofs, trusses etc. can all be built off-site and delivered as building kits ready for assembly. With this technique, the plans are more accurate, as the technology almost completely eliminates “field changes.” Components can be prefabricated, complete with insulation, installations, windows and doors. The trend is towards a higher degree of prefabrication so that the greater part of the building work takes place in an industrial plant in a well-controlled environment with approved quality assurance. Wall and roof panelizing is particularly useful for jobsites that don’t have adequate space to construct the walls. The actual assembly of the building, up until the roof is laid, takes one or two days at the building site. A five-storey building in wood can be complete ten weeks after the foundation is molded.
It is possible to manufacture entire units at the factory, not only with electricity, water and waste pipes installed, but kitchens and wet rooms too; floors are laid and walls papered. Another advantage of building with prefabricated components in wood is that they are relatively light and can be erected at heights of several stories using simple lifting equipment such as mobile cranes, in some cases with the cranes fitted on the trucks that deliver the components to the site. It is cost-effective to build off-site using wood-based methods. With prefabricated wood modules, the total cost is up to 20-25 % lower compared to building on-site. This is partly because the time saving can be up to 80 % compared to building on-site. In Sweden, the market share for multi-storey buildings has increased from 1 % in 2000 up to 15 % today.