4D BIM
Linking model elements to the construction schedule, so the build can be seen — and tested — in time.
4D BIM adds the dimension of time to the model by linking elements to activities in the construction programme. Each object is associated with when it is built (and sometimes demolished or temporarily installed), so the project can be played back as a sequence — a visual simulation of how the site evolves week by week rather than a static end-state.
That time link turns the schedule into something testable. Planners can spot sequencing problems, check that space and access work as trades arrive and leave, and catch space-time conflicts — two activities needing the same area at the same moment — that a purely geometric clash check would miss. It also supports site logistics: cranes, deliveries, temporary works and safety zones can be planned against the real build order.
4D sits naturally between the geometry of the model and the cost view of 5D: the same elements that are scheduled in time are usually the ones measured for cost, so time and money can be planned from one coordinated source.
Need this in practice?
Project Coordination →