The Good Homes Alliance (GHA) has successfully responded on relevant parts of a new report from Energy Saving Trust (EST) highlighting housetypes, including pre-1919 structures, that EST sees as ‘carbon villains’.
Neil May of the Good Homes Alliance warns against leaping to conclusions about who the carbon ‘villains’ of existing building stock are, without further research. Neil May says:
‘There are considerable gaps in our understanding about the actual performance of different building types in the UK. Certainly we have to be very careful not to rely on modelling on its own.’
‘For example it has been shown recently in work by Glasgow Caledonian University and others that traditional solid wall building thermal performance is often a lot better than the modelling predicts. There is also small scale research evidence to show that much cavity walling is a lot worse in reality than modelling suggests. Recent work by Leeds Metropolitan University (using co-heating tests) has shown that many modern buildings have up to twice the predicted heat loss as built compared to design. The suspicion is that the poorest performing stock in the UK may actually be from the 1970s and 1980s.’
‘However the fact is that we don’t have many facts. We need far more high quality research both detailed and epidemiological in order to ascertain the actual performance of building types. So let’s not jump to conclusions which may drive policy or funding initiatives which bear little relation to reality.’
‘Another major problem with the headline grabbing summary of the EST document as reported on Building4Change is that it confusingly mixes up issues of energy supply, building fabric and energy efficiency measures. The energy supply issues may be the key measures in this regard, with very little impact of the fabric itself. On the other hand it may be parts of the fabric not mentioned, such as windows.’
‘The report also picks on 4 particular pre-1919 building types which, according to the EST figures, only constitute 0.73% of our building stock, when in fact pre 1919 buildings overall constitute about 25% of UK building stock. Unfortunately the effect is to tar all pre-1919 buildings with the “impact” of less than 3% of pre-1919 traditional buildings. Also we have to ask what a pre-1919 building is. There is a huge difference in thermal performance of the fabric of Victorian 215mm brick work buildings from 500mm thick limestone walled buildings or 100mm oak framed brick infill buildings. Lumping all pre-1919 buildings together is not helpful either for analysis or for possible solutions.’
‘The use of the language such as “carbon villains” is inflammatory and leads to a conclusion that such villains need dealing with strongly and quickly. This is unfortunate. We need to take time to properly understand traditional building performance (and modern existing building stock performance) as well as the best way to address such issues and the costs, risks and benefits of doing so, before rushing to accusation and potentially damaging judgements and “solutions”.’
EST reported:
Insulating lofts in homes across Britain could create nearly 45,000 jobs, while replacing inefficient G-rated boilers would support nearly 40,000 jobs. A full-scale eco-facelift would support 4.7 million jobs, save around £8.7 billion on domestic energy bills and cut CO2 emissions by around 48 million tonnes. The economic and carbon benefits of housing retrofit are outlined in a new report published by the EST.
Many numbers have been circulated in the quest to promote housing retrofit’s potential to give a boost to the UK’s ailing economy. Home economics – cutting carbon and creating jobs by nation and region, looks at the economic impacts for three ‘scales of ambition’:
- lofts and cavity wall insulation: insulating all remaining fillable lofts and cavity walls on a national and regional level
- insulation and heating systems: lofts and cavity wall insulation plus replacement of the least efficient gas boilers (G-rated) and installation of heating controls in all suitable homes
- advanced eco-refurbishment: a sustainable overhaul of housing stock with advanced insulation, heating systems, and microgeneration measures such as solar photovoltaic (PV) panels fitted to all suitable homes.
Economic impacts for each scale of ambition are estimated taking into account direct and indirect effects. Direct effects are the immediate impacts on the economy resulting from households installing micro-generation technologies or energy efficiency measures eg, sales of equipment and installer employment. Indirect effects also include the effects on the supply chain like manufacturing, re-spend of money saved on people’s fuel bills and employee wage spend.
The report also gives a regional economic picture, saying that anything between 1,000 and 8,000 jobs can be supported in each region with loft and cavity insulations.
Householders’ fuel bill savings are also projected under the scenarios. The first scale of ambition could save more than £1 billion overall on bills and advanced eco refurbishment would save £8.7 billion.
Carbon villains
The report gives a snapshot of British housing stock, highlighting the carbon ‘villains’, perhaps unsurprisingly mainly big, draughty houses heated by electricity and oil. The good news is that there are relatively few of those homes. The biggest problem is owner-occupied and gas heated houses producing moderate CO2 emissions that exist in such large numbers that together they account for a major proportion of overall carbon emissions. But these properties tend to have more space, making them generally suitable for renewable energy installations.
Worst CO2 offenders are:
- pre-1919, electrically-heated, solid wall, detached or semi-detached homes, in poor condition in terms of basic energy efficiency measures (0.07 per cent of housing stock, 25.9 tonnes CO2/ year)
- pre-1919, electrically-heated, solid wall, detached or semi-detached homes, in good condition in terms of basic energy efficiency measures (0.24 per cent of housing stock, 20.7 tonnes CO2/ year)
- twentieth century, electrically-heated, detached or semi-detached homes, in poor condition in terms of basic energy efficiency measures (0.22 per cent of housing stock, 17.4 tonnes CO2/ year)
- pre-1919, oil heated, solid wall, detached or semi-detached homes, in poor condition in terms of basic energy efficiency measures (0.34 per cent of housing stock, 14.4 tonnes CO2/ year)
- pre-1919, electrically-heated, solid wall, terraced homes, in poor condition in terms of basic energy efficiency measures (0.08 per cent of housing stock, 14.2 tonnes CO2/ year)
Housetypes accounting for the largest proportion of carbon emissions are:
- twentieth century semi and detached with basic energy efficiency measures fitted (17.3 per cent of housing stock, 5.5 tonnes CO2/ year)
- twentieth century semi and detached with no energy efficiency measures fitted (7.1 per cent of housing stock, 7.9 tonnes CO2/ year)
- post-1980 semi and detached, gas heated with basic energy efficiency measures fitted (6.4 per cent of housing stock, 5.8 tonnes CO2/ year)
- twentieth century terraced, with basic energy efficiency measures fitted (9.2 per cent of housing stock, 4 tonnes CO2/ year)
- pre-1919 terraced, with basic energy efficiency measures fitted (5.7 per cent of housing stock, 5.2 tonnes CO2/ year)
What are the figures based on?
The statistics are based on the EST’s housing and economic models. The model is based on the English House Condition Survey which was analysed to produce 96 standardised house types about which EST has detailed underlying data. These are characteristic of 98 per cent of the housing stock: the numbers for each house type are then scaled up to reflect their relative proportions and the real total number of homes in Great Britain.
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