What defines an eco home? The term is primarily used to describe those houses which, because of their design, require less energy to run. The main aspect is heating costs, but there are other elements as well. For example, a building may be no more energy efficient than another, but if it gathers energy from renewable sources, such as through wind or sunlight, it too could be described as an eco home. However, ordinarily such a house will also be very well insulated, requiring less energy to heat because energy production and conservation both contribute to the overall environmental friendliness of a building.
Most eco homes make intelligent use of glass and there is more than one reason for this. Firstly, windows are major sources of light. The more light you can get into a building, the less you have to rely on artificial lighting. Obviously, you still need lights for winter evenings and for the night, but on every day of the year there comes a point where natural light has deteriorated such that you need to rely on electric lights instead. If you can push this moment back to even slightly later in the day, you will make an energy saving over the course of the year.
Of course, this saving only makes sense if you aren’t simultaneously wasting huge amounts of energy trying to heat a building that is poorly insulated. It is therefore very common for eco home builders to make use of windows with exceptional insulation qualities.
However, heat doesn’t just escape through glass. The phenomenon of solar gain means that a building can gather heat through sunlight during the day, minimising heating bills. The key here is to ensure that heat is gathered during the winter months, but not during the summer when you will want to keep the building cooler. Vertical, south-facing windows are best for maximising the benefits of solar heating as the light will hit them from the low sun during winter, but not when it is higher in the summer.
The windows are of course not the only area where heat is lost. Every inch of the house plays its part in retaining warmth. This means that cavity wall insulation can prove incredibly efficient as it affects so much of the building, while loft and roof insulation are particularly important because heat rises. It’s also worth paying attention to simple things like seals around windows and keyholes and letterboxes.
Although wind power and hydro power are sometimes used, solar power is by far the most popular form of renewable energy for homes. Government grants have made solar panels affordable and more and more firms are springing up to meet the growing demand.
Many people mistakenly believe that direct sunlight is needed in order for solar panels to gather energy, but fortunately that is not the case – after all, it would make the technology all but pointless in the UK. In reality, whenever there is daylight, solar panels will be gathering some amount of energy. This will be less on cloudy days in winter, but it does still happen.
Carla Harding’s eco home will feature large numbers of windows which are operated remotely. She is currently looking at the controllers offered by Teal Products.