Case Study 4 – Are Electric Boilers A Good Or A Bad Choice For EPC Ratings
Electric Boilers In A Domestic Property
In a domestic property, a gas boiler will always produce a better EPC rating than an electric boiler. This is because it can cost up to 3 times as much to heat a home with an electric boiler compared to a gas boiler.
Because the EPC rating is based on running cost, an electric boiler will always rate lower. If the property is also poorly insulated, it may struggle to meet the Minimum Energy Efficiency Standard of an E rating. If you are considering installing an electric boiler in a residential property, you would be wise to get an epc carried out before you install it so that the exact impact on the epc rating can be determined.
Electric Boilers In A Commercial Property
However, in a commercial property, the epc rating is based on carbon emissions and an electric boiler produces less CO2 emissions than it’s gas counterpart and therefore will rate higher. The running costs would still be high and if wanting to stay with electric, an air con system would be a cheaper option that still has low carbon emmissions.
Because of the high running costs of an electric boiler, you will never find it as a recomendation on either a domestic or a commercial epc.
Case Study Overview
We recently carried out 2 EPCs on 2 very similar flats for a landlord. The main difference was that one had a new electric boiler with an efficiency of 100%, the other had an old gas boiler with an efficiency of only 65%.
These were the rating of the flats
Flat 1 – Electric Boiler 100% efficiency
EPC rating E 52
Flat 2 – Gas boiler 65% efficiency
EPC rating D 62
Comparing electric running costs to gas
In this case study each property has a demand of 6,900 kWh per year to provide heating and hot water to the flat.
So using the cost of the fuel from the fuel comparison table below, the running cost for each flat can be calculated.
*Source: Nottingham Energy Partnership
This example shows that even with a low efficiency gas boiler of 65%, the running costs are still 59.35% cheaper than to heat a home with a 100% efficient electric boiler.
As the epc ratings are based on running costs, the gas boiler will still rate significantly higher.
The EPC will also give a breakdown of the property’s energy performance. This is shown below.
We often get uphappy landlords and homeowners complaining that the epc must be incorrect as it rates their new boiler as being very poor.
In these cases we have to explain that the EPC is not saying there is anything wrong or poor about their boiler, but rather that it is poor compared to other heating sources that could provide heating and hot water to the property in a significantly cheaper way.