Overestimations of the energy performance of new homes are symptomatic of a wider problem in the industry

Pete Halsall

Numerous studies that we and others have carried out over the last 5 years show the performance gap can’t be conveniently blamed on the hapless occupiers.  A microcosm of the inconvenient truth, these studies show that the actual energy performance of new homes can be up to 150% higher than anticipated.

A number of reasons exist for this and they all strongly intermingle. Many of these are industry failures which are compounded by a poor record in enrolling occupiers into their new green homes - and how to operate the services as well as what to do and what not to do. However, with diligence, and reasonable skill and care many of the drivers of ‘the gap’ can be easily avoided. So much of it sits in the school boy error zone. It is apparent that there are a number of pan industry issues that are going to need to be addressed if we are going to face into and solve the challenge.

Firstly, there is no doubt that the higher standards of design knowledge and building practice required for sustainable homes have caught out much of the housing industry in the last 5 to 10 years especially. The response of government to effectively dumb down such standards in response to howls from industry is pretty much the worst thing that it could do from an industry perspective. We won’t get there unless we try and it isn’t easy - but the prize is clearly both worth it and indeed a necessity if we are going to meet our carbon reduction targets. Standards are fundamentally about professionalism and one’s ability where necessary to innovate so that they can be met. All industries - and especially this one - need drivers for improvement. There is a real danger of throwing away the environmental baby with the poorly thought through regulatory bath water by taking away a key stimulus to innovation. 

A culture of investment in establishing a much higher level of technical capability in organisations - including research and development - is going to be essential

As the industry moves out of recession there will no doubt be a surge in new construction and almost certainly a howling skills gap could emerge. We are already seeing quite dramatic effects in some parts of the country with regard to labour inflation rates - and who can blame tradesmen for that after several years of sub economic working. A massive training programme will be required so that new people can enter the industry and be skilled and up skilled to build sustainable homes. Designers and design and build contractors should note the reference above to ‘reasonable skill and care’ -this concept seems to be passing by the unwary but from what we’ve seen the performance gap problem is often a source of considerable potential liability. 

In the US there is the spectre of law suits where designers or developers have made claims about the energy performance of green buildings which have not been met in reality.

There is also a wide knowledge gap. Firstly about the issue itself - and how buildings perform in reality - as well as some of the underlying principles. The in-house building physics champion may be a good idea. We have also not collectively realised that industry culture needs to change quite radically to suit the requirements of sustainable building. We found in our joint ‘avoiding the performance gap’ national training programme (run jointly with LABC and kindly funded by Construction Skills) that culture is a key factor. The actual performance of new homes - in terms of both energy and indeed wider building performance - needs to be taken seriously and indeed understood much more widely.  It doesn’t help of course that many of the large builders merchants don’t appear to stock air tightness tape which is needed to ensure the home doesn’t leak heat . The devil is in the detail. White van man running around to the point sometimes of near exhaustion from site to site is hardly a recipe for well built homes. 

A culture of investment in establishing a much higher level of technical capability in organisations - including research and development - is going to be essential. Our Good Homes Alliance document, “Get Britain Building Good Homes”, and featured in Building last week, proposes amongst other things that a modest levy on new home sales is applied to fund a pan industry research and development fund. I have started this process in my own developments with a commitment to provide 0.5% of net sales value up to £15k per project towards such a fund. One must after all lead from the front. 

Pete Halsall is chair of the Good Homes Alliance