A BIM model is more than a 3d model (we’ve covered this topic here LINK); it is a multi dimensional model. Every time a specific type of information is specified into the model a different dimension is set. So, theoretically, there could be various dimensions…infinite dimensions. However, according to BIM fundamentals there are seven recognized dimensions.
3D = Geometry. The third dimension of BIM gathers the graphical data. It is the most commonly known dimension, as it refers to the “visible” part of a BIM model. Linking different specific models into a federated model allows to develop a clash free project. Model walkthroughs, Clash Detection, Project visualisation, Virtual mock up models, prefabrication are among the outputs that a BIM model may provide.
4D = Time. The fourth dimension of BIM is used for construction site planning related activities. It is possible to visualize and to control the progress of the activities through the lifetime of the project. Builders and manufacturers can optimize their activities: all the deliveries can be managed following the “just in time” approach, thereby reducing storage needs.
5D = Costs. This fifth dimension of BIM is used for budget tracking and cost analysis. Quantities may be extracted directly and instantly from the BIM model with a high accuracy level. By assigning unit cost to the extracted quantities we automatically obtain precise and reliable cost analysis. As a result, if the total cost does not reflect the client’s request, the designer may efficiently proceed with real time amendments and change impact assessment.
6D = Sustainability. The sixth dimension of BIM is used for energy assessment during the design phase and operational phase. An efficient data collection from installed sensors enables to better understand the building’s performance and define a strategy aiming to optimise the building’s energy consumption.
7D = Facility Management. The seventh dimension is used to extract and collect relevant information related to the operation and maintenance status of the facility throughout its life cycle. 7D is the main field where BIM model’s data can definitely make the difference. Starting a Facility Management program based on reliable extracted information from an as-built BIM provide the most effective solutions for the management of a building.
Considering the entire life cycle of a building, the operational phase absorbs up to 70% of the overall cost.
In a BIM model each system, each terminal, each product is individually determined and its position is traced in 3d; any product’s maintenance program is scheduled according to the manufacturer’s specification.