As I embark on building a new house in an elevated and exposed location, I’ve been thinking how it might be possible to achieve an A-rated energy Performance Certiﬁcate.
What I have discovered is that under the current EPC scheme, it’s a lot harder than it looks.
To reduce potential heat loss from the building, I speciﬁed a degree of insulation considerably higher than required to meet building regulations; so I was disappointed to discover that due to the way EPCs work, this would have no bearing on the rating.
The same applies to other energy eﬃciency measures such as high-speciﬁcation windows or the air tightness of the building fabric.
The problem appears to result from the system being designed to measure performance of existing property, in which eﬃciencies are more diﬃcult to identify and measure than with new-build.
The purpose of the EPC system is to provide a benchmark upon which Government can act by means of incentives and penalties to improve energy eﬃciency in buildings. This is partly for the safety and comfort of people, but also to help meet the UK’s 2050 net-zero emissions target – buildings being major energy users.
Anyway, it seems greater weight is given to retrospective measures rather than to embedded eﬃciencies. Accordingly, retroﬁtted insulation, double glazing, solar panels or low-energy lighting are all elements that carry precious points.
I spoke to an EPC assessor who advised that increased insulation gives a diminishing return on investment, which I suppose makes sense in that the ‘payback’ on the investment will get longer as you increase the insulation value i.e. the time taken to recover the investment through reduced energy costs. To my surprise he added he’d never seen an A-rated EPC, only high B ones.
His overall advice? “How about aiming at a level below, and save money in the design speciﬁcation.” It probably makes sense given the circumstances outlined above, but I am rather disappointed that we might not achieve ﬁrst class honours!
In summary, my brief encounter with a system that I thought was relatively robust, given its important statutory standing, has left me questioning how accurate the data really is.