BIM has proved its worth across a wide range of construction programmes. Much of the focus has been on ensuring that projects leave a legacy of accurate and detailed as built data, available through common standards like COBie. This brings major benefits for communication, planning and future maintenance.
With offsite construction, BIM needs to be about more than information sharing. Because offsite construction is a design led process, detailed and accurate geometric design data becomes even more critical. The focus of the 3D BIM model in this environment is more significantly on clash detection, precise assembly methods, tolerances and materials interfaces.
Offsite manufacturing using SIPs demands precision and fine tolerances. While this brings greater discipline and new ways of thinking to onsite operations, the good news is that it also brings superior build quality, fewer defects and reduced maintenance costs to the finished structure.
Fine tolerances have not always had the highest priority in traditional construction projects and tolerance ‘stack-up’ can result in significant gaps and misalignments. But there’s always a way to make something fit on site if needed. With panelised offsite construction, lack of accuracy isn’t an option. Panels and components have to fit perfectly or the structure won’t work.
Design for Offsite
Greater benefits come from offsite construction when it is considered as the intended construction method from the outset, not just one of the options. Early collaboration with specialist design engineers then makes it possible to address issues of buildability, building performance and quality assurance far more effectively.
BIM is critical to all of this. It creates the environment in which collaboration happens and which drives quality improvements with benefits over the lifecycle of the building. The 3D model becomes more than a guide or representation of the intended structure it becomes the detailed blueprint from which panels and components are made.
Because of the importance of accurate geometric design data, the offsite industry is doing much to pioneer the use of level 3 BIM.
