Philip Gray, sustainability associate, BDP
I’m not saying the performance gap doesn’t exist, but it’s more of a gap in communication than the result of poor design. Over the last decade, the measure of energy performance has been led by Part L and EPCs, which anyone will tell you are full of holes. Herein lies the issue: it’s the yardstick that’s the problem.
More advanced tools such as CIBSE TM54 (Evaluating Operational Energy Performance) provide a tested methodology to allow us to more accurately predict actual energy usage, which enables us to provide clients with more (and better!) information. We want our buildings to work as we’ve designed them, but this is as much to do with managing expectation and training users as it is optimising design.
Ian Orme, sustainability associate director, Mace
The government, through Innovate UK and the Zero Carbon Hub, has spent significant amounts of money researching the causes and impacts of variations in performance. For example, the quality of construction can impact energy consumption, but since the introduction of whole-building air-pressure testing, airtightness has improved markedly.
One area that we’ve been working on has been how we can use smart technology to improve how buildings are handed over from construction to occupation. Also, using approaches such as the government’s Soft Landings, is starting to help improve outcomes, particularly for large, complex projects.
Tamsin Tweddell, sustainability team leader, Max Fordham
We will only be able to close the performance gap if we radically change our approach to procuring buildings with contracts and a tender process that actively encourages collaboration between all parties involved in the construction of a building. The current tender process is driven by lowest cost, which in turn drives down quality and this needs to change.
Tender evaluation needs to be based on the ability to deliver the required performance outcomes, with a proven track record. Clients need to be proactive in basing their decisions on outcomes and evidence of past performance.
Dayle Bayliss MCIOB, owner, Dayle Bayliss Associates
The performance gap will not be closed using our current ways of thinking. We need to revolutionise the way we build – we need to change the methods of construction and the systems that support it. Key to this is encouraging new innovative thinking into the industry.
We need thinking from outside construction, from other industries and to bring a diverse range of people into construction. Trying to close the gap by improving traditional methods won’t work: we need new thinking.
Stephen Wielebski FCIOB, construction consultant
If you start from the premise that you can’t manage what you can’t measure, it puts the matter into context. We are making progress in terms of collating evidence but this is just part of the process, albeit quite a fundamental aspect. For example, how representative are stated U-values? What confidence do we have in these, and similarly the science that underpins linear thermal bridging?
Yes, it is possible but at this stage not entirely. Let us not forget the need for skills, in particular technical knowledge. Sadly, these are rapidly diminishing, likewise the frequency of experienced technical people occupying key boardroom positions. This is where the necessary leadership needs to come from.
Zainab Dangana MCIOB, sustainability R&D manager, Wates Smartspace
It would require a coordinated approach. The design and construction team, including the end-user, should be involved throughout, the design intent must be carried through the construction process and all stakeholders should be responsible for the performance of a building after it is completed for a period of time.
The performance of materials and components should not be predicted in isolation but as systems constructed on site. End-users should be educated on the use of systems in their buildings: the occupant use of a building has a significant impact on actual energy consumption.
