If you’ve looked at buying a house these past few years you’ll have noticed that each property on the market must have an Energy Performance Certificate, or EPC. This grades the energy efficiency and carbon consumption of the home. Although the basics are pretty easy to understand (its a colour coded scale with red being the least efficient and green the most), I never really understood how it was calculated, why there are two columns (current and potential), and why nearly all the houses I looked at seemed to rate quite badly!
Now that we’ve put our house on the market and had n EPC done, I thought I’d share with you what I found out about them.
1. To achieve the full 92-100 marks a house would basically have to be a passive house. Passive houses are a German gold standard of energy efficient homes; super insulated structures built to take advantage of natural resources for all their energy needs eg. large windows to the south side to capture lots of warmth from the sun. As far as I’m aware there is only one certified passive house in the UK (as featured on Grand Designs) so its obvious that the super high marks are out of the league of the average home.
2. I hadn’t realised that the structure of the home is taken into account as well as features like heating, windows, insulation etc. In basic terms the more external walls you have the lower your score will be, so a detached house like ours is inevitably going to come in with a lower score than a flat or terrace. According to the assessor, the highest mark he had ever given was 80, and that was for a flat with only one external wall and eco heating.
3. The potential mark points to how green a house could be given its situation, construction etc and the actual shows where its at now, so, in a way, if the actual mark is close to the potential mark, pretty much everything that can easily be achieved in a property has been done, such as double glazing, energy efficient boiler etc. You can change the potential of your home with quite drastic (and expensive) measures like cladding the property in insulation.
So how did we do?
As you can see we scored a pretty respectable 69 out of a potential 70. Where did we loose that 1 mark? Well we put some halogen spotlights in the kitchen a couple of years ago, and as they’ve been dying we’ve been replacing them with more energy efficient LED’s but there are still 3 halogen bulbs left, and that’s what lost us the mark – grrr!
The report also gives you suggestions as to what you could do to green up your home, and ours were:
1. Change to energy efficient lightbulbs throughout – which we will do, but I don’t like the idea of throwing out something functional so we’ll continue to do it as and when the bulbs go.
2. Install Solar Water heating – would love to but as you can see our only south facing roof is taken up with a 2.5kwp solar PV system it’s not actually possible.
3. Clad the building in super thick insulation – for green points and energy saving I should really consider this, but the reason I love my home so much is that it has exposed stone walls throughout and I wouldn’t want to loose them. We have super insulated the roofspace so hopefully this makes up a bit for lack of insulation in the walls. Also, as the walls are about half a meter thick I can’t imagine they are that bad for letting drafts through!
The other interesting thing the report gives you is an estimate of how much CO2 your home uses to run in a year. Apparently our house uses about 3 tonnes, maybe even less as I’m a bit tight with the thermostat and keep it at a comparatively cool 17-18 degrees all winter. I can only find quite old data regarding average CO2 emissions, but figures from 2006/7 suggest that the average person uses around 10-11 tonnes per year, so 3 tonnes for running a home with four people in it doesn’t sound too bad, although the dream of a carbon neutral life still sounds far away!
Anyway, I think most people resent the 60 or so pounds it costs to have an EPC done on their homes before they put them on the market, but I found it quite an interesting exercise and it really made me think again about how we live our lives.
If you fancy testing how much carbon you use I’ve found the WWF footprint calculator quite inspirational in the past. Its well worth thinking about what you use an how you could lessen the amount of resources your household consumes, and often the smallest changes, like changing a lightbulb (!) can make the most difference.
Ta ta for now,