Whether you are considering investing in solar panels, solar water heating, heat pumps or any other green source of energy for your home, the first step you should take is to improve your home’s insulation. This will ensure that you maximise the use of natural resources and don’t waste energy. If you skip this step, you will end up spending a lot of money buying a very powerful system to cover the energy needs of a badly insulated house.
Insulation is one of the most efficient ways to save energy at home since it keeps it warm in the winter and cool in the summer. In fact, the Energy Saving Trust estimates that in one year a typical three-bedroom semi-detached house can save up to £310 on energy bills by installing loft and cavity wall insulation.
High energy bills for your home eat into your income, and they’re also a sign of a high carbon footprint. It’s important to bring your bills down, and fortunately, there’s a very easy way — make sure your home is fully insulated. The most important part of that is insulating your loft.
An uninsulated house leaks heat like water through a sieve. You have to pump out far more heat than you actually need just to keep your home warm enough. It escapes through the walls and floor, as well as through doors and windows, but more heat escapes through the roof than any other part of the building.
That’s because of one of the most basic laws of physics, that hot air rises. This means that, as the air inside your home warms up, it heads upwards to the roof, and an uninsulated loft gives it a clear route to escape. Not only are you paying for all that heat you aren’t using, but its generation pumps an alarmingly large amount of carbon dioxide into the atmosphere, contributing to global warming. The carbon dioxide comes from running your boiler more than you need to.
There are two ways of insulating your loft, but whichever method you’re using, you need insulation between the joists to a depth of at least 270 mm, giving the U-value of 0.16 required under building regulations. There are various materials available, but mineral wool provides a reliable and inexpensive option.
This will prevent heat getting into the loft in the first place, so if you want to use the roof space as a room, which needs to be kept at the right temperature, you’ll also need insulation between the rafters on the underside of the roof. Whereas fitting insulation between the joists isn’t too difficult, roof insulation is strictly a professional job.
If you are going to board your loft out to store items. Be sure you build the joist up with timber. What I mean by this if you put the boards on to the existing joist, you will compress the loft insulation. So if you have 270 mm of insulation, you will compress this down to 100 mm the depth of the joist. For loft insulation to work it has to be big and fluffy. Warm air is trapped in the air pockets and this is how it keeps the heat in.
Loft insulation isn’t expensive to have installed, and the good news is that it lasts for at least forty years, so once it’s done you can forget about it. The exact cost depends on what kind of house you have, but even a large detached house shouldn’t cost more than £400.
For that, you can expect to save around £240 to around £310.00 a year, meaning you’ll get your money back inside two years, as well as cutting your carbon footprint by 1,000kg. Smaller properties will both cost and save slightly less, but the payback time is similar.