Are our green buildings really ‘Outstanding’?
The fact is that we don’t know, says Christine Murray
This week we address the elephant in the room - the energy performance of buildings. It turns out that few of our buildings actually perform as they were designed and expected to - indeed it’s shocking just how bad we are at predicting building energy use.
At the AJ green breakfast last week, hosted by Feilden Clegg Bradley Studios and part of the Green Sky Thinking programme, the panelists gave brave, tell-all presentations that revealed just how poorly we’re doing.
The average building tracked through CarbonBuzz consumed twice as much energy as predicted, according to Aedas sustainability director Judit Kimpian. That’s on average - many performed far worse. And without post-occupancy evaluation and analysis, often we just don’t know why.
What is more, because BREEAM ratings do not require mandatory post-occupancy evaluation and are not reviewed after completion, as far as we can tell no one knows whether a building’s performance is actually ‘Excellent’ or ‘Outstanding’ once the occupants are in.
Sarah Cary, sustainable development executive at British Land, described the issue as not so much a performance gap, as ‘…a gaping hole. We do not monitor buildings with people inside.’ But Cary also stressed that one of the reasons we aren’t very good at predicting performance is that it’s not very easy to do - especially when it comes to collecting meaningful and comparable data. Cary was keen to point out that nobody actually knows exactly how Energy Performance Certificates are calculated, making it difficult to predict how you’ll perform against them.
The silver lining to this cloud is that some practices are actively trying to close the gap between predicted and actual energy use, and they are making inroads. But they need buy-in from the wider industry and clients to make it happen.
At the breakfast gathering, Ian Taylor of Feilden Clegg Bradley Studios described a litany of comic errors hampering the monitoring of their buildings. ‘We have seen metering that is installed, but not monitored by the BMS, and meters that have been commissioned, but do not exist,’ he said.
But Architype now incorporates rigorous metrics as part of their design and handover process, and offers post-occupancy evaluation as an additional paid service. Jon Ackroyd describes this as a beta process, akin to the installation of IT equipment, where, after handover, the architect is on hand to monitor energy use, tweak settings and ensure the smooth running of the building. Best of all, it’s a service for which they charge an additional 0.6 per cent fee.
Clients are willing to pay for post-occupancy if it will save them money. Kimpian said they saved a school client between £30,000 and £70,000 in bills a year by helping them tweak the lighting and heating settings, and by fixing a lock so the client stopped propping open an external door.
Future head of school Fionn Stevenson said Sheffield University was committed to teaching students about how to read and analyse metering data, so that we can raise a generation of architects who will be able to undertake this kind of data-driven energy snagging.
With this issue, we are launching the AJ Bridge the Gap campaign to share best practice in metering, post-occupancy evaluation, analysis and troubleshooting. What we need from the profession is data and anecdotes, good and bad, so that we can assess where we are with building performance evaluation, and the road ahead. The government has already been in touch to say they’ll be watching this space. Let’s bridge that gap together.