Possible Carbon Footprint improvements for our house

Image by Ken Kitson

In a previous post I described how I'd signed up for the  Mayor of London's Green Concierge Service which helps Londoners improve the energy efficiency of their houses. Part of the service was to provide an energy assessment of your house which I described in that earlier post. The next bit of the service was to provide some ideas for how you could improve your particular house. What was really great was it gave some indication of how much difference each improvement measure to your carbon footprint so you could really see what was worth doing, and what might just be "window dressing". Here's the chart produced for our house which shows which measures would make most difference for our house. Sorry that the chart is a bit hard to read on a web page - let me just give the main points. The assessment estimated our house's carbon footprint at about 7.6 tonnes per year. The most effective measures we could take, and the % reduction taking just that measure would achieve, were:

  • having a bio-mass (i.e. wood burning) boiler - 48% reduction

  • wall insulation - 18% reduction

  • triple glazing - 13% reduction

  • solar photo-voltaic panels - 13% reduction

  • upgrading our gas boiler to a more efficient gas boiler - 10% reduction

If we took all the possible measures - we could reduce the house's carbon footprint by about 60% or 4.5 tonnes per year. (Note you can't just add up all the percentage reductions for each single measure, because once you have improved one area, improvements in other areas will have less effect. Also some measures - the gas boiler or bio-mass boiler - were alternatives). The results were really fascinating ... for example, it appeared that solar thermal heating would do little to reduce our footprint. The really big win would be to switch to a biomass boiler - the only really low carbon way of heating a house like ours. But there are formidable obstacles to using one in a city location ours - first and foremost that we would need to have about 6 tonnes of wood delivered each year! Anyway more about how we follow this all up in future posts......