How does it work?
Our working practices have not completely changed, our core deliverable will still be our drawings, but in their creation we are able to generate a ‘virtual’ three dimensional (3D) version of your project that we can use to collaborate and co-ordinate with all project parties to validate design choices.
Each element within the 3D model has been given information to ‘carry’, this information can be accessed either by viewing the model or through its export to spreadsheet templates (CObie).
Typically a column may carry basic information such as its size and material, but along with this we are able to define its cost, installation date and associated hazards, even its future maintenance schedule.
What is the format?
Buildings are modelled to ultimately provide COBie (Construction Operations Building Information Exchange) spreadsheet information, which is very accessible by virtue of it’s simplicity. The downside is that maintaining such simplicity requires a vast volume of information and the COBie spreadsheets have ultimately been labelled as cumbersome and unhelpful as an individual file. However, the COBie files can be read and manipulated by a number of specialist software packages to extract pertinent information for a specific discipline.
What is REVIT?
AutoDesk REVIT is a software which Design Teams use to undertake the 3D modelling in a BIM compliant environment, which can translate a model into COBie spreadsheet output. There are Architectural, Structural and MEP (Mechanical Electrical and Plumbing) specialist variants within this AutoDesk range. There are alternative software packages to REVIT, but this is the software Cambria Consulting and most of our design team colleagues use.
What’s all the fuss about?
REVIT modelling is a virtual build, where the model and the contents therein have intelligence. Each element is not only a model member resembling a part of the building, but is a perfect 3D model of the actual component. When these elements are interrogated the user gains many “dimensions” of information. For example, click on a column, and you might learn the column reference, size, weight, cost, installation date, associate hazards, source, original paint specification and future maintenance specification.
Why isn’t everyone using it?
It has taken a long time to get to this basic level of industry wide coordination and recognition of a universal system that is accessible to all. Software and training is expensive and therefore it is viewed by some as simpler to maintain current systems. Furthermore, most of the features listed above are not practically achievable until the entire construction industry ‘buys in’. We are able to model generic items, but to gain the full benefit and access to the higher dimensions, manufacturers (particularly MEP) need to be producing a REVIT virtual model of their bespoke item for accurate inclusion.
Why is that important?
The perfect modelling of all constituent parts enables clash detection of elements, for example, a duct running through a structural beam. Furthermore, the creation of operational rules can be applied and check layouts, for example, do all doors open fully without hitting lighting rafts?.
The industry is now beginning to explore some of the wider implications of the various “dimensions” of information, and categorised as follows:
- Time/Schedule(4th Dimension)
- Estimate/Cost/Expenditure (5th Dimension)
- Life-cycle features (6th Dimension)
A design team ultimately passes the finalised model to the contractor to build, and a highly sophisticated model will be able to offer 4th and 5th dimension information and would provide invaluable data.
The largest benefit is anticipated to be related to 6th Dimension Life Cycle features and BIM has the potential to provide end users, facilities managers and ultimately demolition contractors all of the required information in a quick accessible model (or COBie spreadsheet for manipulation by other specialist software).
What are levels of BIM and iBIM?
Level 0 = AutoCAD
Level 1 = Basic 3D modelling
Level 2 = 3D modelling with data rich objects allowing clash detection etc
Level 3 = 3D modelling with data rich objects and full COBie output and potential iBIM
iBIM integratedBIM describes a fully integrated approach whereby there is only one central project model. All disciplines work from that model and hence clash detection is somewhat redundant. We are not aware of any commercially successful iBIM projects, as there are significant hurdles (model ownership, responsibilities, designer warranties etc).
Who does the clash detection?
An ifc file is becoming the industry standard for data exchange of BIM information. So whilst we can overlay and compare an Architects and Structural Engineers different BIM models within REVIT, the universal language of ifc, allows specialist clash detection and inspection software such as Navisworks.
This can be done by the Lead Designer however, Cambria Consulting have historically been appointed to undertake this role and have previously been selected on the basis of being regarded as industry leaders and having the most advanced BIM knowledge and software of the Design Team members.