Epc certificate and energy usage

oldskoo1

We are moving house and for the first time looking at epc for efficiency.

I must admit I have no idea what it is meant to show and how it relates to energy usage.

Why I ask is our house is 4 bed detached, 14 years old, well insulated etc, heating on 24/7 and bills are low. The rating was D on ours.

Our new house is rated C and more efficient but it's a lot bigger, 3 story new build with 5 bedrooms.

I would have thought it costs a lot more to heat so why is it listed as more efficient?

MX5huggy

An EPC rating is worked out on per meter squared. Not total heating cost.

On the full EPC (not just the fridge rating graph but Estate agents show) it will have total kW required to heat each building and the cost of those kW using the current fuel and boiler.

If comparing 2 EPC's see that they were produced using the same same software version. It changed in April (i think) fro rdSAP 2005 to 2009. The ratings and kWs used should be similar but the costs where updated.

MX5huggy

In addition an EPC on a new build should be produced using a full SAP calculation this is much more detailed.

SYNERGY

oldskoo1 wrote: »

We are moving house and for the first time looking at epc for efficiency.

I must admit I have no idea what it is meant to show and how it relates to energy usage.

Why I ask is our house is 4 bed detached, 14 years old, well insulated etc, heating on 24/7 and bills are low. The rating was D on ours.

Our new house is rated C and more efficient but it's a lot bigger, 3 story new build with 5 bedrooms.

I would have thought it costs a lot more to heat so why is it listed as more efficient?

Look at EPC's as no more than an indication of potential energy consumption / savings, in ideal controlled conditions.

Look on it as similar to fuel consumption figures given for motor vehicles.

Eg. 1.4cc car, manufacturer states 40 mpg, driver A gets 28 mpg, driver B gets 50 mpg !

Same car but different usage gives different costs.

So looking at your old house compared to your new house.

Band D is 55 - 68 efficient.

Band C is 69 - 80 efficient.

Theoretically the difference between your old house and your new house could be at worst 1% ( 68 - 69 )!

In this instance, you have a larger area / volume to heat at only 1% better efficiency, your heating costs must be greater for the same comfort level.

On the other hand if it was old house 55% new house 80% then you're on a winner by 25%.

To sum up, you should be better off heating wise due to the improved EPC value, but when all said and done you are heating a greater volume.

All being well you may find you are heating a larger property for the same money or slightly less. :j

rogerblack

In addition, EPCs are not always correct, and your recourse, if they are inaccurate, may be very limited.

SYNERGY

rogerblack wrote: »

In addition, EPCs are not always correct, and your recourse, if they are inaccurate, may be very limited.

True they are not always correct, mainly on older properties, due to there being too many assumptions within the data gathering process and data marked down to zero due to no or limited access, ie no access to loft area to determine depth of insulation, if any.

New builds, on the other hand, should be pretty well accurate.

oldskoo1

Thanks everyone for the advice

It shows ours as having a score of 62 and the new house a score of 73 with the potential of being 78 whatever that means.

But I understand these figures can be inaccurate. At least they are both fairly new builds, 14 years for ours, about 8 years old for the new property.