The recent push towards energy efficiency has encouraged people to insulate their houses, use more efficient devices and consider how much they are spending on electricity bills. As a result, per-person electricity consumption has declined over the past few years, but it’s important to understand how your house performs in terms of efficiency. So how do you calculate the potential electricity bills of a potential new home?
How Are Electricity Bills Calculated?
Electricity is usually divided into two payments: the standing charge and the number of kilowatt hours used.
- The standing charge is a consistent charge that loosely represents the day-to-day cost of connecting your property
- The number of kilowatt hours (kWh) you use is the amount of electricity that you use
In an ideal world, there would only be one or two ways of charging, but many electricity companies still make this relatively complex. Sometimes, if you use a certain number of kilowatt hours, you will be charged one rate, and if you go over that, the remaining kilowatt hours will be at a slightly lower rate.
For a 30-day month, your bill might look a little like this:
- Standing charge (14p per day): £4.20
- 250 kWh used (16p per kWh): £40
- 111 kWh used (14p per kWh): £15.54
- Total: £59.74
If your home already has a smart meter, calculating your potential bill is relatively easy. Simply open the smart meter’s display and navigate to the history section. From there, you can usually select the date range that you want to check, whether it’s for winter, for a specific month or for an entire year. However, this relies on access to the property and to the smart meter.
Without A Smart Meter
If you’re thinking of buying a house and you can’t check previous energy bills, however, you will need to make some educated guesses.
First, start with a base figure of £80 per month for gas and electric, assuming that mains gas is available as well. If the house is heated by electricity, start with a base figure of £110.
Take the age of the property, and add 10% for every century it existed in. Therefore, for a property built in 1995, you would add 10%, whereas for a property built in 1895, you would add 20%.
Then, take the number of bedrooms it has.
- For 1 bed, subtract £20
- For 2 beds, subtract £10
- For 3 beds, keep it even
- For every bedroom above three, add £10 per bedroom
The next stage is to account for the EPC rating. An EPC is required by law when selling your home, so it should be available online. Here, we’ve assumed that the base EPC rating is a C, so for houses that have a C rating, you don’t change anything.
- A: Subtract 10%
- B: Subtract 5%
- C: Keep it even
- D: Add 4%
- E: Add 8%
- F: Add 13%
- G: Add 20%
Finally, consider your own usage. If you are a heavy user, allow 5% extra. This usually means that you have a small workshop with a number of power tools, spend a lot of time in the garden with an electric mower or perhaps game heavily on a powerful system. In addition, if you work from home, allow another 3% for use throughout the day.
These figures will vary substantially depending on how well the house is insulated, how warm you have it, and whether you have any additional source of heat, such as a wood burner. As a rough rule of thumb, these figures should work well.