Setting the right objective

Published:  11 May, 2010

HVCA, zero carbon

Opposition to the push for zero-carbon buildings is growing because of the potential cost. The money would be better spent on low-carbon refurbishment, says Sue Sharp.

It is becoming increasingly clear that we will not meet our climate-change targets if we insist on pushing for zero-carbon buildings. The extra cost required to turn a low-carbon building into a zero-carbon one is not in proportion to the environmental benefit.

The BRE has estimated that it will cost 25% more to build a zero-carbon building compared with the current cost of a new build that complies with Part L of the Building Regulations. Most builders quote the 80/20 rule; It takes 80% of the cost to deliver the final 20% of carbon-saving benefit. You don’t need to be a maths genius to work out that this is not bright.

Current legislation calls for all new homes to be zero carbon by 2016, with commercial buildings following by 2019. With a new Government having to grapple with the largest spending deficit in living memory while also trying to deliver a low-carbon economy, it makes absolutely no sense to put finances under further strain by insisting on this hugely expensive strategy. It would be far better to concentrate our resources on where we can extract maximum benefit — i.e. improving the energy and carbon performance of existing buildings.

We currently replace less than 2% of our building stock every year, so if we are serious about reducing energy waste and carbon emissions we should be concentrating on existing buildings through a systematic process of low-carbon refurbishment. We should also focus on it in a way that keeps costs under control, both up front and on-going. According to engineering firm Arup, 75% of energy-efficiency improvements are effectively cost neutral because they pay for themselves in reduced running costs to the end user.

This should be music to the ears of FMs and building-services specialists as the key is making the best of what is already installed and working to improve the performance of ‘traditional’ building-services technologies. We cannot afford the capital investment to rip out and replace services on any grand scale. In any case that is not a sustainable approach, and this is the big contradiction of successive Governments’ obsession with renewables. The new Feed-in Tariff system is in real danger of distorting the market by incentivising people to invest in an expensive renewable solution that might not be appropriate for their building when a far better use of the money would be to improve what is already installed.

Building owners need to understand the principle of the energy hierarchy where you first tackle basic improvements such as improving insulation, upgrading windows, adding controls to existing energy-consuming appliances, adopting solar shading to reduce overheating in summer and, perhaps, looking to make better use of passive systems such as daylighting and natural ventilation to reduce energy demand. Only then should you consider additional technological changes to further reduce energy costs and carbon emissions.

Minimising disruption is also often a key consideration, as working buildings need to remain up and running as much as possible while improvements are being made. This, again, often mitigates against more radical changes such as adding renewables.

Heat pumps are one possible exception because the latest models can produce heat up to 65°C, which makes them suitable for adding to existing heating systems, often as a direct replacement for boilers — so giving the end user a more energy-efficient solution without having to carry out wholesale changes to the installed system.

HVCA, zero carbon
Improving the energy performance of existing buildings will give a much better carbon return on investment than attempting to deliver zero-carbon new buildings.

All the financial incentives encouraging the uptake of renewables risk adding complexity to buildings and threaten to undermine sustainability. As an industry, we need to encourage simplicity so that end users can understand how to operate their buildings efficiently. It is all very well designing a low-carbon building, but the proof of the pudding is in the operation and as more Display Energy Certificates (DECs) are applied the more evidence is emerging that many buildings do not operate as they were designed.

This point has not been lost on the new Chief Construction Adviser Paul Morrell. His Low Carbon Construction Innovation & Growth Team (IGT) recently published its ‘Emerging findings’ report that highlights the need to ‘develop a clear proposition for low carbon retrofit’.

He has called for each local authority to produce a renewable-energy strategy and stock audit that considers existing buildings, not just new build, ‘with a view to providing the opportunity to deliver energy and heat solutions for both’.

The new Government must act on this and change the focus so that our industry is given the legislative and financial drivers to make a real difference in existing buildings. We cannot afford to be distracted by all the political froth and noise around zero carbon because, impressive and worthy as that is, it is not what will deliver the results we need.

The Carbon Trust is making interest-free loans available to businesses to help them make their buildings more energy efficient. This is a sensible use of public money and has the potential to deliver quick returns. The massive subsidies for renewables are not sustainable — either financially or environmentally.

*Sue Sharp is the new chair of the HVCA’s Service & Facilities Group.

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