The 80/80 challenge

Published on Wednesday, 14 April 2010 01:00
Written by Dr Peter Bonfield

In December world leaders gathered in Copenhagen (COP15) to agree carbon reduction targets in the race to halt the acceleration of global warming

and its potentially catastrophic effects on the planet. Despite the considerable efforts of global leaders, no agreement was reached on targets.

While the talks and negotiations like COP15 are hugely important we need to accelerate the actions that will reduce our emissions and prepare us for future climate change. We need to tackle the big carbon producing activities further and harder and we need to do it now. Even if the scientists are found to be scaremongering with accelerated projections (which is unlikely) the economic argument alone should spur is into action: fossil fuel is running out, its costs are increasing at a rapid rate. Recent research by says that the average household energy bill could nudge £5,000 a year by 2020 if current price trends continue.

While there is good progress being made on various fronts we have so far failed to adequately tackle buildings and homes which account for 50% of the UKs total emissions. Of this, existing homes - 80% of which will be still with us in 2050 - account for 27% of all the carbon generated in the UK. They are our single biggest carbon offender and where most potential improvement can be made.

The 80/80 Challenge

If we are to have a fighting chance at meeting the 2050 target set by Government which commits us to an 80% reduction in carbon we must address existing stock - the 80% of homes here now and reduce their carbon output by 80%. This is a huge and difficult challenge.

Significant progress made on new homes

In 2006 Government introduced the Code for Sustainable Homes which set out very challenging targets for new homes and a timeline in which these had to be delivered. The first Code Level 6 homes (the 2016 target under the Code, (which includes ‘zero net carbon' amongst other environmental impact targets) was delivered on the BRE Innovation Park in 2007. While it was by no means easy to deliver and there is still a lot of learning about the best and most cost effective ways to achieve sustainable housing. However a significant number of developers and supply chains have been rising to the challenges and have learned a great deal about the underpinning principles of sustainable house building - careful product selection, good design, building (air)tight, ventilating and incorporating renewable technologies into the mix. But it's a much easier proposition when you have a blank canvas to start with as is the case with a new home. Existing homes, with their enormous variety of build methods and conditions represent a much larger challenge.

Learning and Innovation

Progress against the Code has been significant. The trial homes built on the BRE Innovation Park and now out in the field have experimented with a number of innovative solutions and provided invaluable learning. This has shown that there is no ‘one size fits all' solution, but that delivering against the Code can be tailored to local requirements and business solutions. The Government, BRE and other stakeholders have also learned a great deal on how well the Code functions. This is important in refining and improving it as the state of the art improved.

Although there remain a number of sceptics and companies who would prefer the Code to disappear because it has the potential to adversely affect their businesses, there are others who are proactively and positively embracing it. For example the Technology Strategy Board has recently provided financial supported to an innovation/research project called AIMC4 which aims to deliver Code level 4 housing at lower or equivalent cost, with fewer defects (snags), less waste, and shorter and more predictable build times (giving improved return on capital) than current housing

Materials, design and construction

The emphasis of this project is on materials/product selection, effective design and better construction practices, rather than on more expensive renewable energy technology solutions. The project partners include BRE, Barratt, Crest Nicholson, Stewart Milne, H & H, Oxford Brooks.  Others will join the partnership.

The scale of the 80/80 challenge

Existing housing

The UK domestic stock is the oldest in Europe and consists of some 25 million dwellings. It is currently responsible for nearly 150 million tonnes of CO2 per year, which is 27% of the UK's greenhouse gas emissions. 37% of English homes are still rated as non-Decent, with just over half of that number failing to provide adequate thermal comfort.

To deliver on the 2050 target, 650,000 UK homes will need to be refurbished every year up to 2050 achieving an improved energy efficiency levels of 80%. A big challenge and enormous undertaking.

Existing housing stock currently achieves an average Energy Performance Certificate (EPC) rating of D/E and more than 5 million homes achieve an F/G. To achieve an 80% reduction, the average EPC rating will have to be brought up to a band B or better, a level only currently achieved by 1-2% of housing stock.

 ‘Hard-to-Treat' (HTT) homes constitute a substantial proportion (43%, i.e. about 10 million dwellings) of the stock and are responsible for half of domestic CO2 emissions. They are also expensive to treat and, have not thus been subject to major refurbishment. These are dwellings that have single skin solid walls (there are more than 6 million of these in the UK, mostly Victorian or earlier), or no lofts, or are off the gas network and/or are high-rise flats. Remedies for these  homes  involve implementing unfamiliar, innovative solutions using new skills, techniques, technologies and products.

Energy efficiency measures

There are  a wide,  growing and perhaps bewildering range of measures that property owners can implement  to improve the energy efficiency of their home.

Some measures, like loft insulation, draft excluders and cavity wall insulation (for housing with wall cavities!) are simple and effective. Changing to an improved boiler system is also likely to be effective but requires more expert advice to make the right choice. Further measures such as the most appropriate for of internal wall insulation or the most cost and carbon effective renewable energy system or the correct mechanical ventilation heat recover system are more difficult to specify and procure.

This is because the solutions need to be properly tailored to the house construction type and its condition. To add to this mix, there are a number of new, exciting and innovative products that are being assessed for use. These include highly efficient aerogel insulation, phase change (temperature moderating) products and smart metering. Global, science based companies like St Gobain, DuPont, 3M and BASF are investing considerably in developing these products for use in existing buildings.

So, on the positive side, there are now a whole host of solutions that have the potential to cost effectively reduce CO2 emissions from existing housing. However, on the negative side, the wide and growing number of solutions and the requirement to ensure that the right measures are implemented for a myriad of house types and conditions makes the selection of the right solution challenging at best and downright confusing at worst!

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