Forget what you think you know about energy efficiency

If there is one thing that anyone who knows about domestic energy efficiency knows, it is that loft insulation is the most cost-effective measure. The Energy Saving Trust (EST) suggests the saving may be £180 and cost not much more than that to install. It is an obvious measure - or is it?

The National Energy Efficiency Database “was set up by DECC to provide a better understanding of energy use and energy efficiency in buildings.” It published its latest findings in November on domestic energy efficiency measures and the results are shocking. On homes three measures were tested: loft insulation, cavity wall insulation, or a new boiler with the energy savings calculated. It found that on average in homes with mains gas, loft insulation reduced gas consumption by 1.7%, cavity wall insulation by 7.8% and a new boiler by 9.2%.

Although there are some caveats about the findings, the information is the most robust data in this area. As has been pointed out, this suggests that loft insulation will save the average home £20 a year. This may be the final nail in the coffin for the current Green Deal, which assumes much greater savings.

In my home we rely on a fiddly ring with pins that are clicked in or out for when you want the heating, meaning the heating comes on at 6am on a Sunday when I am asleep.

As I said before in a previous Building blog the opportunities for technology combined with training are fantastic and can deliver more definite savings. However, despite the availability of technology most of us either do not have even simple controls or do not know how to use them. 

In my home we do not have a room thermostat, and for a timer rely on a fiddly ring with pins that are clicked in or out for when you want the heating. It does not even allow for different settings on different days, meaning the heating comes on at 6am on a Sunday when I am asleep. This is on a boiler installed in the last 18 months.

When we can stream movies on a train surely we should be able to control our homes in a better way? We can. There have been programmable thermostats for a long time but now more advanced controls are available. Nest, which has been in the news following a takeover from Google is a company trying to bring an Apple style of simple effectiveness to home controls with a thermostat you can control using a smartphone and learns. British Gas have also launched Hive, a similar device for £200 including installation, a comparable price to loft insulation that will almost certainly save a great deal more money, energy and carbon emissions.

Although they are both designed to be simple to use there is still a long way to go for people to get the best out of their systems. The EST has recently conducted a survey that indicated most of us don’t know how much energy things use or how controls work.

The conclusion is that although we should continue to roll-out insulation where it is proven to work - surely specific research on why these measures are not delivering the calculated savings should be carried out? - a national programme of training and the roll-out of smart controls would be much more cost-effective. Both could occur in the same home visit.

Barny Evans is principal consultant, renenwables and energy efficiency, at WSP