02 July 2012 #Construction
The Government Construction Strategy requires that a Level 2 Building information modelling (BIM) (with all project and asset information, documentation and data being electronic) is in place and in use on construction and infrastructure projects by 2016 at the latest. It is essential that the construction industry adopt a more collaborative approach and processes. It is intended that BIM will, relatively shortly, impact on every discipline in the supply chain of all projects.
ARUP define BIM as being:
“Not a product or proprietary software program, but a set of integrated processes built on co-ordinated, reliable information about a project from design through construction and into operations”.
BIM is already in use, and serving as a differentiator when it comes to tendering for works. The UK`s biggest privately-owned building firm, Laing O`Rourke, has said they believe their use of BIM was the `main catalyst` of their appointment on the major Leadenhall Tower project.
The UK government itself began trialling BIM in February 2012 with 4 pilot projects, initially to be let by the Ministry of Justice. Other major organisations, including well-known retailers, have committed to use of BIM on all new build projects.
BIM is therefore a process involving the generation and management of digital representations of physical and functional characteristics of a facility. The resulting building information models become shared knowledge resources to support decision-making about a facility from earliest conceptual stages, through design and construction, through its operational life and eventual demolition. (National Building Information Modelling Standards (NBIMS) Committee).
As such, BIM is a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life-cycle; defined as existing from earliest conception to demolition. (National BIM Standard - United States).
There are 3 levels of BIM. Using BIM Level 2, models are created individually by designers and then joined together on regular basis for coordination/clash detection etc. There are 5 dimensions to BIM. 3D BIM = 3D model of Building/Asset; 4D BIM = 3D + time [planning/programming]; 5D BIM = 4D + cost.
The Government has set up some 7 or 8 working groups, run out of the Cabinet Office. The purpose of these various working groups is to address different specific issues, eg contractual terms, the way models are owned and how ownership can be transferred, and how best to obtain a co-ordinated approach to adapt existing Plans of Work to take account of BIM, to avoid unnecessary industry fragmentation etc., to include which deliverable should in principle be handed over by the supply chain at different Work Stages.
How is BIM intended to work?
A BIM system can produce drawings, not based on lines, shapes and text boxes but on data sets that describe objects virtually, in the same way that they will be handled physically. However, the real benefits it is hoped BIM will provide are in the true interoperability and the capability for proper integration, allowing the inputs of the various professionals and specialists to come together in the Building Information Model.
On a technical level the Industry Foundation Classes are an open specification for BIM and are used to share and exchange BIM in a neutral format among various software applications. Green Building XML (gbXML) is an emerging schema focused on green building design and operation and is used as input in several energy simulation engines. gbXML is one of a large number of building energy simulation tools available on the market. When choosing which simulation tool to use in a project, the user must consider the tool`s accuracy and reliability, considering the building information they have at hand and which will serve as input for the tool.
Advantages of BIM
It is anticipated that the main advantages that will accrue from use of BIM in project design and build are:
Potential Disadvantages of BIM
The use of BIM goes hand in hand with a more collaborative approach which requires a change from the current culture where each consultant can have very separate responsibilities. The ‘interoperability’ risk is also seen as one of the main disadvantages of BIM. Will different software programmes be compatible if consultants are using different products? How reliable is the software? As BIM becomes more widely used, and the software more standardised, ‘interoperability’ should become less of an issue.
For contractors and consultants who are required to use BIM, there will be an initial outlay to invest in software and training, running to many tens if not hundreds of thousands of pounds. This may lead to higher fees to recover at least some of the cost of the initial investment. There may also be some duplication of work if contractors are required to produce 2D drawings for smaller sub-contractors who do not work in 3D or for planning authorities who generally require paper copies of 2D drawings.
Potential Legal Issues with BIM
A key issue for the construction industry and all in the supply chain will be how the requirements of BIM impact on terms of appointment and services, to include on IPR, responsibility and PII cover. The introduction of BIM also brings with it significant potential impact on software/hardware and communication links.
Some of the main concerns centre on whether use of BIM will affect the design liability of the consultants and contractors involved in a particular project. Provided the documents are carefully drafted to ensure that the services capture all BIM related activities, and there is a clear notification and review procedure of the model as it develops with input from other designers, the design process may not be far removed from current practice.
We are working with several of our clients that are actively involved with the development and roll out of BIM and will look to provide regular updates over the coming months as the implementation of BIM progresses and the consequences of that implementation become clearer.