Green BIM

Mac Muzvimwe
Ever since publication of the UK Government Construction Strategy in May 2011, Building Information Modelling (BIM) has been the hot topic. Prior to that, it was 'sustainability' - so, what has happened to it?

Has BIM meant the demise of sustainability? Certainly not. At Faithful+Gould, we believe BIM and sustainability go hand in hand.

So, what is Green BIM? It is about using BIM tools for creation of successful sustainable designs and ultimately, green buildings (i.e. buildings with low operational carbon).

A BIM model is a digital representation of the physical and functional characteristics of a facility; therefore, a designer has the opportunity to undertake several simulations and analyse the potential impacts of the design before committing to it. This is also known as Environmental Performance Modelling, and it entails the use of analytical and simulation technologies to improve sustainable outcomes.

A BIM model is a digital representation of the physical and functional characteristics of a facility...

Simulations can be used to find the ideal building orientation, and to calculate the potential return in energy and the feasibility of each system, until performance is optimised. Examples of such simulations include:

  • Building orientation – the position of the building relative to the path of the sun, and the impact on energy use and efficiency.
  • Daylighting – allowing good access to natural light for all the building occupants without compromising thermal efficiency and comfort. Natural light is better than artificial light; it gives building occupants a sense and feel of connection to the outside and it is free!
  • Building mass and envelope – manipulations of the building form to determine the comfort and efficiency of the building mass and systems, including quality, glazing, permeability, etc. By choosing the right mass for the building type and climate, the designer has a great chance to influence the building's overall energy needs.
  • Energy modelling – consideration of various factors that affect energy use in a building in order to predict the building's energy demands and impact of the design on the global environment, i.e. the ability to calculate real-time energy and water use levels. Energy performance calculations remain a challenge, but use of BIM technology could bring positive outcomes to that process.

The technology is developing rapidly, and embracing BIM will enable us, as an industry, to contribute positively to the UK Government’s target of a reduction of 80% in greenhouse gas emissions by 2050. It is estimated that in the UK, buildings account for at least 40% of the UK’s carbon emissions; therefore, green buildings will contribute significantly to reduction in carbon emissions.

It is estimated that in the UK, buildings account for at least 40% of the UK’s carbon emissions...

BIM has a lot of 'green' potential, which has not yet been unlocked, particularly calculation of a building's embodied carbon, for example:

  • Adding parameters to BIM objects, which then report the object's BRE Green Guide rating.
  • Extracting quantities from the model and entering the data into the BRE Green Guide Calculator Tool.
  • Creation of a Carbon Calculator "plug-in" to link with the BIM model. This would then use the model data and ordnance survey data to calculate travel distances and carbons emissions associated with the transport of goods to building sites.

Being part of the Atkins Group, Faithful+Gould wholly supports Carbon Critical Design, and as part of our core service, we work with designers to ensure that carbon is a core consideration when capital projects are evaluated, designed and procured. Through use of BIM and other technologies, we now also offer as a standard service automatic carbon calculation reporting from cost plans prepared using the New Rules of Measurement (NRM) structure. With time, we hope to be able to fully utilise BIM to perform whole building life cycle analysis. We have also invested in a four-year BIM engineering doctorate in collaboration with the University of Reading, and one of the programme objectives is to explore the BIM potential.