TSB funding Embedding the principles of ‘POE’
The Technology Strategy Board (TSB) is running a four-year, £8m programme to promote Building Performance Evaluation (BPE) in all its forms, writes Roderic Bunn. The objective is to obtain a greater understanding of the difference between anticipated performance of new and refurbished buildings, and their actual in-use performance. The motivation for this
work goes back to the PROBE (Post-occupancy Review Of Buildings and their Engineering) research project in the 1990s, the results of which were published in editions of Building Services Journal (CIBSE Journal’s forerunner). The findings drew attention to the credibility gap between design intention and reality. Although
unstoppable trend towards design-and-build (D&B), Aedas was keen to study whether the procurement route had an impact on the buildings’ achieved performance – would D&B deliver long-term value or contribute to higher operational and maintenance costs? Are lower design-stage EPC ratings, which the government and BRE are relying on for improved energy performance, matched by lower energy consumption in use? How significant is the role of occupant engagement in achieving low-carbon expectations? Would different ventilation strategies affect comfort differently, and would natural ventilation bring about lower energy use? Would technologies such as biomass boilers, ground- source heat pumps and solar water heaters reduce carbon emissions as planned? The R&D group at Aedas led the
investigation and teamed up with University College London’s (UCL) Dejan Mumovic and researcher Esfandiar Burman to identify the causes behind the differences between the predicted and achieved energy use of buildings. This is a thorny issue. As BPE participants pointed out at a Roundtable held
www.cibsejournal.com
PROBE popularised post- occupancy evaluation (POE) as a technique for understanding how buildings are performing, the industry was wary of POE and unfamiliar with the assessment tools. The TSB’s programme
of work therefore intends to embed the principles of POE and project feedback throughout the supply chain as an essential and routine part of construction procurement. The aim is to upskill the construction industry in post-occupancy feedback tools, such as thermography and airtightness testing, CIBSE TM22 for energy assessment, and the Building Use Studies (BUS) method for carrying out occupancy surveys The TSB is funding two
types of study for domestic buildings: post-completion
at Aedas last September, very few buildings have a realistic design-stage energy use prediction against which one could compare operational energy use like-for-like. Compliance calculations (Part L and EPCs)
bear little resemblance to actual consumption. As the Aedas-designed CIBSE|RIBA benchmarking platform CarbonBuzz points out, they only focus on fixed building services at fixed occupancy and operating hours, excluding any operational factors such as the intensity of use. So Aedas R&D and UCL have been looking to take the BPE process a step further and construct a more realistic ‘prediction’ of energy use that takes into account operational factors. In the process the team has begun to gather evidence that demonstrates these ‘operational risks’.
‘Design’ vs ‘as-built’ Part L and Energy Performance Certificate (EPC) assumptions are often unrealistic in terms of system efficiency and building fabric. For example ground source heat pumps in reality often don’t contribute as much as assumed during design. U- and
March 2012 CIBSE Journal 41
and early occupation; and in-use post-occupancy. For non-domestic buildings, studies can be for buildings under construction and those in operation. Studies are ranging
across a variety of building types including schools, care homes, offices and innovation centres. To date, research is
being carried out on 3,663 dwellings on 32 sites nationwide, and 40 non-domestic buildings, of which eight are under construction and 21 are in the education sector. The results from all the studies will be made public. For more information on
the programme, visit
www.innovateuk.org
Roderic Bunn is a building performance evaluator at BSRIA and the Technology Strategy Board
What sets schools apart is the scrutiny they have had to undergo in terms of energy performance
Photo courtesy of Aedas
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84