As part of its drive to reduce costs and carbon while improving outcomes in public sector construction, in March 2011 the UK Government published A Report for the Government Construction Client Group - Building Information Modelling (BIM) Working Party Strategy Paper. It outlined a strategy for the use of BIM to make key information available in the right format at the appropriate times during the procurement process. The objective is to create higher quality information that will help to make better informed decisions, thus reducing risk and avoiding waste due to reworking.
The report Cabinet Office Government Construction Strategy published in May 2011 stated that Government would require fully collaborative 3D BIM (with all project and asset information, documentation and data being electronic) as a minimum by 2016. (It's worth noting that Government has not set a contract value where projects are required to use BIM.)
The Government has embarked on a four year programme for sector modernisation, working with industry to reduce capital cost and carbon emissions from the construction and operation of the built environment by 20 per cent.
Central to these ambitions is the adoption of information-rich Building Information Modelling (BIM)
technologies, along with process and collaborative behaviours that will unlock new more efficient ways of working at all stages of the project life-cycle.
Focusing on outcomes
The Government is starting to focus more on the outcomes from its construction programmes, a change in the way that procurement is normally approached. For example, the objective of a hospital project will be to provide an environment conducive to healing and recovery. This will result in shorter stays for patients, fewer medical complications, and a corresponding increase in capacity for the facility.
In a parallel activity, the Government is aiming to mandate the use of Soft Landings in government departmental procurement. The aim is to ensure that the performance of new and refurbished government buildings matches the design ambitions after three years of operation. The Soft Landings worksteps will therefore be dovetailed into the Government's BIM process.
What information is required?
There are two types of information to be made available for Government BIM projects by 2016. The first of these is the 3D BIM model, an electronic virtual representation of the building and its facilities, services and systems. 3D BIM software is capable of reproducing any level of detail, down to the smallest component or element.
3D CAD has traditionally been used to improve design modelling. The improved visualisation of plant and structural elements gives a better understanding of the design of the building. It can help to detect possible clashes which may go undetected until the design reaches site.
However, there are important distinctions to be drawn between 3D CAD and a BIM model. Items or objects shown in 3D CAD are made up of a series of lines. Once drawn, they will always exist as just a series of lines, they don't have any other attributes.
An object in a BIM model is different. Whereas a fan coil drawn in a 3D CAD model is purely a visual representation of that item, when created in a BIM model it exists as an actual object - it takes on certain attributes which define characteristics of location and position, and which system it belongs to. A lot of data can be added to an object, such as performance, physical dimensions, connections, even asset and maintenance information for use during operation.
This ability to link information to an object within the model is what helps put the 'I' in BIM.
While early 3D visualisation can help a client understand what they are getting, and the design team can see how their particular systems and components fit within the structure, the core objective of BIM is the management of information. This extends beyond the model - or data held within the model - to cover all relevant information that is valuable throughout the life of the building. This brings us to the second type of information, the Construction Operations Building Information
Exchange (COBie) spreadsheet.
The COBie format is intended as a mechanism for conveying all the key information about the building and its services along the supply chain and eventually to the client for use by the facilities team post-construction. COBie spreadsheets should hold enough information about each item of plant or piece of equipment to enable facilities managers to specify replacement components, or maintenance needs.
The COBie spreadsheets need to be populated with information and given to the client at predetermined information exchange points (known as data drops) throughout the procurement process, but specifically at points where the client is required to make key decisions. In most cases the spreadsheets can be populated by certain basic building data directly from the model.
It is important to note that the COBie spreadsheets do not contain any fields for the performance of m&e plant or equipment. Therefore these must be added manually at each information exchange stage, a considerable task on most projects where BIM will be used.
It's all about the information
While BIM will help achieve the Government's desire to have the right level of information about a project available at the right point in the procurement process, maximising the benefits of BIM will require the information to be accessible to all intended users. In view of this, a wider debate is needed on what should be in the BIM and what the links should be.
All major construction projects employ a document management system to organise and store a vast amount of design and construction information. The key is to capture it and make it available, in a readily accessible format, for use by the people charged with operating the building throughout its life. A robust system introduced at an early stage can avoid having to reproduce data and information again after handover.
John Sands is a principal consultant at BSRIA and a member of the Government BIM Working Group. For more information contact firstname.lastname@example.org.