BIM and the future of sustainable design

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The potential of Building Information Modelling (BIM) is vast, but most UK design and construction companies are at the early stages of use. Beyond eliminating waste and lessening re-work, BIM can offer more systemic benefits for teams concerned with sustainability in buildings, writes Sarah Graham, UK sales manager, Integrated Environment Solutions.

In the US, those involved in the design and construction of ‘green’ buildings are enthusiastic users of Building Information Management (BIM) software.

Last year, a survey by the US Green Building Council and McGraw Hill found that nearly half (49 percent) of BIM users who carry out environmentally-certified projects used it on a majority of their projects; that compared with only 28 percent of “non-green” users.

Moreover, 78 percent of the survey respondents who were not using BIM on green building projects expected to be doing so within just three years.

That growth is expected to be reflected in the UK. Last year, the British government’s chief construction adviser, Paul Morrell, said that bidders and contractors on future public building projects would be asked to use BIM. The Government Construction Client Group Building Information Modelling (BIM) Working Party Strategy Paper has been produced as a result. The document outlines a strategy to increase BIM uptake over a five-year programme as part of a plan to improve performance of the Government Estate in terms of its cost, value and carbon performance.

The potential of BIM is vast and the benefits wide ranging. However, most UK design and construction companies are currently at the very early stages of implementation. Many of those who have taken the step towards implementation consider BIM as a 3D alternative to 2D plans, sections and elevations. Largely driven by the government’s BIM strategy the industry is about to enter a new phase of BIM, which focuses more on the information that can be held and shared on BIM-enabled building projects.

Basic BIM

There is a debate to be had about exactly what BIM means, but for the purposes of this article BIM is a generic term referring to the concept of Modelling Information about a Building. BIM in whatever form, is potentially complicated and introduces a new way of thinking about and dealing with project-related information.

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Partners involved in a BIM-enabled project typically collaborate to plan everything from inception to delivery, including groundworks, superstructure, mechanical and engineering (M&E) services, structural design, bills of quantities and the rest.

Productivity gains might not show for the first few projects on which an organisation pursues a BIM-enabled solution because of the potentially sharp learning curve.

On the plus side, BIM offers designers and constructors a chance to sort out real-world issues long before the project starts on site and is much less costly than fixing things in steel, concrete and glass. In fact, productivity gains of 30 percent and a 50 percent drop in requests for information during construction have been recorded on projects where 3D BIM has been implemented, after the initial learning period, according to a 2007 article by Rick Rundell, Cadalyst.

Clearly the use of BIM can eliminate waste and lessen re-work but even ‘basic’ BIM can have more systemic benefits for teams concerned with sustainability in buildings. With the environmental net tightening on construction, tales of projects having to be redesigned at the last minute because they do not achieve the desired BREEAM rating or comply with building regulations are commonplace.

Whole-life engineering and BIM

There are even greater benefits for clients who decide to fully exploit BIM: following project completion, for example a facilities management database can be directly populated using BIM data. As elements cross from the design into real-world usage, their performance and longevity can be evaluated, tracked and logged.

Greater knowledge about, for example, how long the integral blinds in a particular window unit lasted can help in developing a preventative maintenance programme, feed into the sustainability strategy, or might result in the boycotting of those particular window/blind configurations on future projects.

It is not surprising that one of the companies most interested in BIM is Laing O’Rourke. Among other things the contractor is notable for its investment in improved construction processes (such as offsite manufacturing and preassembly) and its keenness to engage in PFI projects such as Pembury Hospital, Kent and University Hospital of North Staffordshire in Stoke.

With the environmental net tightening on construction, tales of projects having to be redesigned at the last minute because they do not achieve the desired BREEAM rating or comply with building regulations are commonplace

The company’s web site says: “BIM models enable tighter control, more informed decision making and better planning by bringing together a host of information about a facility’s physical and functional features across its lifecycle. Using BIM, every component, material or package of works can be isolated and interrogated against a limitless range of criteria.”

Given that PFI signatories not only design and/or build the asset, but also own and operate it, the benefits of thinking about maintenance and running costs from the very first are clear: every faulty blind, every wasted kilojoule of energy eats into Laing O’Rourke’s profit margin over the life of the project.

Performance analysis and BIM

Performance analysis is a natural partner to the integrated design process (IDP) that BIM promotes. By taking an integrated approach throughout the entire project building professionals can create high performing buildings and achieve the best sustainable solutions.

Key elements of an integrated performance based design process are:

  • Early discussion of the various important performance issues and the establishment of a consensus on this matter between client and designers.
  • The inclusion of subject specialists in the process (e.g. energy simulation, daylighting, comfort, acoustics).
  • Testing of various design assumptions through the use of performance analysis throughout the whole process to provide objective information on choices.
  • Clear articulation of performance targets and strategies which are updated throughout the process by the design team.

With the main challenges of an integrated approach to design and construction being around interoperability, the vision is to improve the information exchange between 3D modelling packages or BIM tools and performance analysis applications, then the user can start to look at ‘the round trip’ whereby information is taken back into the BIM package from the analysis package.

Figure 1: Future Technology scenario in support of an Integrated Design Process.

Figure 1 illustrates a possible future scenario wherein changes to the BIM model automatically update the performance analysis model, the cost model, the mechanical design package and the facilities management database.

Research on the IFC mBOMB1 project carried out in 2005 and led by Taylor Woodrow, showed the huge potential of being able to link data models automatically.

In essence the various applications were all linked to a 3D BIM model. This meant that if there was a change in a room area in the BIM model, the heating and cooling loads would be re-calculated, which in turn would re-size the ductwork supplying air to those rooms.

The Bill of Quantities and the FM database would be also be automatically updated simply by reading the BIM model on a regular basis and picking up any changes.

To reach this point we need to employ more advanced methods of exchanging data than we currently do, however the potential for doing this has been realised and we are starting to see evidence of the industry drivers necessary to make this a reality. We are still some way off the idealised vision of interoperability shown but we are definitely on the right path.

Designing a whole community

Where might the future for BIM and sustainability lie? Well, given that any element can be given any value, a far broader usage — unlimited, in fact — is surely not far away. As some attempt to create settlements that more resemble eco-towns, data which pertains to the settlement and its environment as a whole can be entered by increasingly diverse parties.

If used properly, BIM could be used to create more sustainable, profitable and people-focused communities.

It is not just M&E contractors and groundworks engineers who could communicate over a virtual model: how about councils, conservationists, transport operators? As each party adds information e.g. likely population type, species habitat, CO2 emissions per unit might change. Who knows what surprising things we might find out when a particular parameter is tweaked?

Perhaps we should not be surprised if this future sounds like a version of virtual reality game The Sims overhauled by a Chartered Institution of Building Services engineer. From Google Earth mashups tracking traffic flow, to iPhone map overlays pointing you to your nearest cashpoint, to virtual/real-world communities such as Foursquare, the benefits of simulating the real world in a computer environment are quickly becoming clear. One day, we might be able to add ‘affordable, sustainable communities’ to the list. www.iesve.com

1 IAI UK (2005). IFC-mBOMB Lifecycle Data for Buildings: Opportunities for the IFC Model-Based Operation and Maintenance. Business Round Table, Kenley, UK.

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