The truth hurts
Display Energy Certificates are slowly revealing the truth about actual building energy performance, which is rather different to what some developers would like us to believe, says Mike Malina.
Many of the newest buildings are actually the least energy efficient. This is rather a shocking conclusion, but it is backed up by the evidence of the first series of Display Energy Certificates (DECs), which are now required in many premises accessed by the public.
There is also a clear difference emerging between the results of Energy Performance Certificates (EPCs) and DECs when they are applied to the same building as an additional exercise. The EPC concentrates on the design and predicted energy performance of the type of building as a comparative benchmark with its peers. The DEC measures and presents the results of the actual energy performance of the building.
While the EPC showed the building as ‘better’ or ‘good’ in terms of its design type, the DEC, in a number of cases, revealed that the building was actually using a thumping 230% more energy than it should.
Government buildings are clearly not immune. For example, the Home office building in Marsham Street (completed in 2005), achieved an F rating on its DEC. The Parliamentary offices at Portcullis House (completed in 2002) scored G — the worst possible rating for energy efficiency.
At the recent BSRIA Briefing in London, Bill Gething of architects Feilden Clegg Bradley Studios pointed out that there was a great myth about new buildings. Many described as ‘green’ by their developers were in fact scoring around F and G when their actual performance was analysed by the Usable Buildings Trust, which specialises in post-occupancy studies. Hardly any were at, or even close to, the target B rating for energy use.
‘Targets and truth are so far divorced from each other they are hardly worth talking about,’ he said — adding that gas for catering and electricity used by IT/communication systems were accelerating at a frightening rate and this was a hard thing for building-services engineers to tackle.
Mr Gething also exploded another myth that we will be able to meet our growing electricity needs from renewables.
‘To provide the power to air condition a heavily glazed building by renewables would need unfeasibly massive PV arrays,’ he said. ‘And even if we covered the whole country with forests we would not be able to provide enough biomass for our future heating needs.’
There is a combination of factors impacting on building performance. A lot of this is not to do with technology but with human behaviour. How are buildings being managed? What priority is really given to the correct operation of the building services? How much effort is being put into managing energy use and making the building occupants aware of their responsibilities for managing their own environment?
These considerations are absolutely fundamental, and we need to step back a stage to when the building services were completed and the building handed over. What happened during commissioning? Even more fundamental, were the services commissioned at all?
Sadly the role of commissioning is much misunderstood by the wider industry. This has been due to lack of knowledge, poorly structured training and varying approaches to building programmes, which often lead to the vital commissioning process being squeezed as projects overrun.
The same applies to building controls. If the brains of the building are not performing, the building services will not be properly co-ordinated. Heating and cooling working against each other is something we see far too often in British buildings. Occupants at one end of such buildings are too hot and those at the other are too cold, so some are opening windows while others troop in carrying portable electric heaters. This means the building operator is paying several times over for energy. It is tantamount to throwing money out of the window at the hot end and having to pay twice at the cold end.
Climate Change Minister Ed Miliband’s pledge to reduce carbon emissions by 80% by 2050 is a complete pipe dream unless there are some radical changes to the way we manage our existing buildings. The key is to establish a hierarchy of need that starts with minimising energy use and subsequent environmental impact from the outset. A step in the right direction is the emphasis now placed on commissioning in the current Building Regulations. This needs to be enhanced and heavily enforced. It’s no good just sticking a piece of paper on the wall (your DEC) and saying ‘that’s it’.
The DEC is an ultimately futile gesture unless heavy fines for building operators who miss energy targets and fiscal incentives for those who hit them are combined to make energy savings a reality. This starts with making continuous commissioning and recommissioning compulsory so that users are forced to tackle existing systems before they consider sticking a wind turbine on top of a failing building.
Feed-in tariffs for micro-generation could be another step in the right direction — although the electricity grid infrastructure needs to be examined if this is going to work. At least these have appeared among the proposed revisions to the Energy Bill, but sadly with no timetable for their introduction attached.
There is one other rather bitter irony running alongside all of this. We are also seeing the results of the first mandatory inspections of air-conditioning systems, which is another requirement of the European Performance of Buildings Directive (EPBD). Some inspectors discovered that many systems were not working at all or had been poorly commissioned or controlled. As a consequence, putting them back into correct operation will actually increase energy use — the ultimate Catch 22.
However, it is far more likely that significant energy savings can be made if it becomes compulsory for the building operator to implement any recommendations made in the inspector’s report — and this may well emerge from the revised EPBD in 2010, as will wider application of DECs so that eventually all buildings will need one.
A combination of commissioning, energy certification and continuous assessment, all backed up with real legislative teeth and proper enforcement is an absolute priority. Unless this happens Mr Miliband can forget his 80%; in fact, he can forget the previously agreed 60% carbon reduction too. Targets without real practical steps for achieving them are absolutely meaningless.
Mike Malina is technical advisor to M&E Sustainability, a joint programme run by the ECA and HVCA, and director of Energy Solutions Associates.