The future of construction is driven by information but what do we mean by ‘information’ when it comes to BIM? We explore the realities of digital construction and the information powering the revolution.
And it’s rich with information
While traditional design focusses on graphic representation, it is missing the data that represents the deeper elements of information; the primary, secondary and tertiary information that uses behavioural data to predicts how individual elements and the asset as a whole will perform. This includes information like when components were installed, anticipated replacement times, estimated energy performances, etc., and this is the kind of information detail that is inherent to the BIM process.
To provide this information, a model relies upon what are called BIM objects. What are they? Well, in short, they’re visual representations of information – defining a product, defining its geometry, representing physical characteristics, providing behaviour data. Visually, BIM objects are recognizable in their appearance and behavioural elements. This allows the user to position an object to determine if it will work as intended and discover any problems or clashes much earlier on in the process.
There are two types of BIM objects. Components are fixed in size and shape. Component objects include things like boilers, air conditioning units, windows and doors. Layered objects are not geometrically fixed, and they include things like carpets, and walls and ceilings.
To ensure that the information underpinning the BIM process is correct is a big challenge. Key to that task is ensuring that the BIM objects used provide secondary and tertiary properties that define more than just physical geometry in order to create an overall model that can be analysed. For example, if the BIM objects representing the walls and doors of a space consistently including a fire rating property, then the model can be analysed for a fire strategy. The same principles apply other properties such as energy efficiency, durability, acoustic and structural performance – of the building as a whole and the individual elements and spaces within it.
The structure of the information is also important. A BIM model is a living design, so objects must be easily added, removed, and moved around. Integration of this new information must be simple, without the need for re-keying or converting information into new formats. This requires a common data environment with a standardised hierarchical data structure.
The right information
To ensure that the correct information underpins the BIM process is a big challenge. Most important is the need to ensure that the BIM objects used have properties that define more than just their corresponding physical object’s geometry. This then allows the overall building model to be analysed.
As an example: If the lighting objects in a building information model include detailed geometry and material properties, they can be analysed for energy performance and then broken out into a detailed lighting model where lighting levels, shadow placement, etc. can be analysed to ensure visual comfort. The same principles apply for all of a building’s properties – such as acoustic performance, durability and structural performance of the building as a whole or the spaces and/or elements within the building.
If BIM is to truly work as a digital flow of information from building design through to operation, then the correct information of physical products must be represented within the model, and a logical information structure must be created to allow construction and facilities management professionals to consistently add new and revised data to the model.
Source: The information in BIM | NBS
