Green Sky Thinking: Making Buildings Work @ Arup
Arup’s quick-fire format explained that successful building design is all about performance
Arup’s offering for Green Sky thinking was 14 talks, limited to 4 minutes each. The format showcased the breadth of Arup’s built environment work and limited the speakers to the most pertinent points. The dominant theme of the evening was the performance gap between a building’s predicted and actual behaviour.
Introduced by David Richards, the speakers were:
- Mike Stych – Improving building performance
- Stephen Hill– Reducing carbon in a commercial market
- Darren Wright - Performance Means?
- George Walker - The Perks of Energy from Waste
- David Healy - EPC is bo**ocks
- Ben Glover – One Man’s Rubbish is another Man’s Gold
- Mel Allwood – Low Carbon Buildings theory meets practice
- Roy James - Chiswick Park
- Guy Channer - Aberdeen Library
- Jonathan Ward - Designing Performance
- Craig Irvine – No.1 Oxford Street
- Giorgio Buffoni - Façade for Al Bahar Towers
- Farrah Hassan-Hardwick - A story about No 8.
A particular highlight was David Healy’s entertaining talk entitled, EPC is bo**ocks, addressing energy rating certificates in the UK. New buildings and those being rented or sold need an Energy Performance Certificate (EPC). Public buildings require a Display Energy Certificate (DEC). DECs are based on the actual energy consumption of a building and EPC are based on a computer model prediction of a building’s energy consumption. Healy compared 99 buildings that had both certificates. He found no correlation between the EPC and DEC. On this basis Healy argued that DEC was a fair measure and EPC was not. EPCs do not include unregulated energy use and different simulation software delivered different answers. Arup’s own office has an EPC rating that is a ‘B’ but a DEC rating that is the equivalent of an ‘F’. The Arup team argued that this difference was commonplace within London officebuildings and that this highlights the gaping performance gap between design intention and outcome.
Mell Allwood presented her own research on the performance gap. Using 15 flats in Brixton, she compared their predicted and actual performance. Allwood’s survey found that actual energy performance was twice that of the predictions. She interviewed the occupants to find out why. Her reserch showed that the occupants had a preference for higher temperatures than the default model assumed; that there was, in reality, no temperature difference between bedroom and living room temperature in a small flat; and that occupants who smoked used significantly more energy because they opened their windows to ventilate the flat. In addition, Allwood found that the occupants didn’t know how to programme their heating. The conclusion to her work was that good performance relies on occupants’ understanding low-energy technology, correct installation of the technology and making sure that the assumptions in energy models reflect the reality of occupant behaviour.
Stephen Hill spoke of the importance of post-occupancy evaluation to ensuring that buildings perform well but he believes that while current practice is starting to value green design it doesn’t put value on green performance. In his opinion, post-occupancy evaluation must be made mandatory to ensure that performance is what matters.
Other highlights included two presentations from George Walker and Ben Glover about producing energy from waste and Craig Irvine discussing how a long lead-in-time for No. 1 Oxford Street, a development on top of the Tottenham Court Road Cross-Rail station changd the design team’s approach to sustainability. Dave Richards said extreme attention to detail was essential to achieving good performance in building design and sport, using an image of British Cycling to illustrate his point. This was echoed by Micheal Stych who talked about ensuring that design assumptions are correct and that simple things can make a big difference. He summarised by saying that design needs to be simpler but smarter. Farah Hassan-Hardwick gave the final presentation. A business development leader rather than engineer at Arup, Hassan-Hardwick gave us an occupant’s view of how Arup influenced the design of their own office and the difficulties of closing their own office’s performance gap.
The Arup talk, a quick overview of the currrent work of built environment team, gave an engineer’s perspective on one of the most significant challenges confronting the industry.