Extracting CO2 emissions data from architects has been as hard as pulling teeth, writes Hattie Hartman
The AJ committed to publishing CO2 emissions data (kgCO2/m²/year) with all building studies when the magazine relaunched in October 2007. It sounds simple, but it’s actually been a nightmare.
Of the 50-plus projects published during this period, we were only able to obtain numbers for roughly half of the buildings, excluding projects built abroad and a number of transport projects where buildings are not hermetically sealed. Gathering this information requires myriad emails and phone calls to project architects and service engineers, and even then, we’re still not confident that we are really comparing apples with apples.
There seems to be no rhyme or reason why numbers were not provided for certain projects. Fifty per cent is shockingly low, given how much we all talk about sustainability now. Rogers Stirk Harbour + Partners did not provide a number for its Heathrow Terminal 5 – the excuse was that it was not yet operational, but these are predicted numbers. Sergison Bates did not report a number for its Parkside housing in North London, and neither did Elder and Cannon for its primary school campus in Edinburgh. The most common excuse is that the buildings predate the building requirements for this legislation.
Architects cannot leave this task to others. It’s too easy to say ‘I’ll call my service engineer’
Of those that do report, numbers in the 20s are very good – see Architype’s own offices in Herefordshire and Hamilton Associates’ office park in Luton. The numbers for Feilden Clegg Bradley Studio’s SciTec Building at Oundle School in Northamptonshire are so good (20 reducing to 12) that one must go back and ask exactly what they are doing to achieve them. Numbers in the 40-65 range are quite acceptable if Bennetts is able to design City office space to the standard seen at New Street Square in London. And David Chipperfield’s Am Kupfergraben Gallery in Berlin is high at 126, though museums are notoriously energy-hungry.
Looking beyond the actual numbers, two things are important. These are predicted numbers at design stage and do not include all operational energy use (in particular IT loads). This will start to change as Display Energy Certificates become more widespread. It’s also critical that these numbers are revisited to compare predicted figures to building performance in use. Bill Bordass of the Usable Buildings Trust points out that predicted numbers can be off by 3 or more.
The key to clarifying this data is post-occupancy evaluation (POE). But just this week, a seminar on the subject at Oxford Brookes University was cancelled due to lack of interest. Two other initiatives are to be applauded: Carbon Buzz, the RIBA’s online benchmarking platform for building energy use and the UK Green Building Council’s Campaign for Real Data. They should be supported.
Architects cannot leave this task to others. It’s too easy to say, ‘I’ll call my service engineer’. We need to push ourselves and challenge our engineers to bring clarity to these numbers. They must become familiar currency and a meaningful barometer of a building’s energy efficiency.
Hattie Hartman is AJ sustainability editor