And the cheapest, cleanest energy is that we don’t use
How does insulation work? – either through thermal resistance (meaning the heat takes a lot longer to escape) or by trapping air. Building materials are rated on their effectiveness with an R value (U values are for the whole building). The Energy Saving Trust has lots of information on the costs of installation, annual savings on bills and carbon emissions as well as what to look for and beware.
30-40% of heat loss from an uninsulated home is through walls, typically Cavity wall insulation is easy to do, and costs £700-£1,000. A solid wall will cost £9,000-£18,000 – you can either insulate the wall externally or internally, which is more sympathetic but also disruptive as wiring, sockets and radiators have to be moved. Either a (breathable) lime render or wood fibre board is needed.
25-30% of heat loss is through the roof Loft insulation is easy. You can use a mineral fibre, one made from recycled bottles or (if you’re not using a grant) sheep’s wool. Spray foam is not breathable and expensive – bad on two counts. Just insulate the loft floor. Though if you have a room in the roof you will need to insulate the residual area above the ceiling. The depth required depends on the material but is 200-300mm. (A whole tonne a year is saved by insulating the roof of a detached house or bungalow – a huge step in the right direction to a sustainable footprint of just over 2 tonnes for everything).
15% of heat typically is lost through doors and windows Installing energy-efficient glazing has a disproportionately positive effect on our comfort by eliminating draughts (and wind chill factor!), noise and condensation. Curtains reduce draughts.
10% of the heating in an uninsulated home is lost through floors If you have a cellar or live on a hill and have a void under the floor there are a variety of products you can use. Ensure ventilation. If you’re stuck with a concrete floor use a good quality underlay to your carpets.
Buyer beware. Do get independent advice and do your research before approaching installers.
Milborne Port library will have a thermal imaging camera on loan so you can see where the heat is leaking from your home. We also have one.
HUG 2 (Home Upgrade Grants 2) is a second government scheme awarding grants to Local Authorities. Somerset Independence Plus (https://www.somersetindependenceplus.co.uk/ ) are submitting a bid. The application is for £7.2m for retrofitting 400 homes (insulation improvements and decarbonised heating upgrades) off the gas network with low EPCs and low householder income, delivered over two years.
Safe and Warm Somerset (https://www.cse.org.uk/projects/view/1367) supports residents with reducing energy bills and keeping warm at home.
Sources: Energy Savings Trust and Ridgewater Energy. Peter Bywater of the former operates in Dorset (where they currently have grants available) but would advise us in Milborne Port on the understanding that any work would not be funded by grants.