Energy performance certificates (EPCs) are a useful indication of how much it might cost to heat the home you want to buy.

All well and good; that’s what they were designed for in the first place when they were introduced back in 2007.

But over the years their function has changed. They are now being used as a grading system to drive improvements in energy efficiency, based on a checklist of measures such as roof insulation, double glazing and the type of heating system that’s installed in the property.

The problem is that the EPC is too blunt a tool for the job, with the potential to do more harm than good especially for rural buildings.

As part of the Government’s drive to hit net zero emissions by 2050, all residential rental properties will have to gain a band C on their EPC by 2025 (2028 for existing lets) to be able to be let, or if they can’t reach a C, landlords will have to prove they have spent up to the £10,000 cost-cap trying to get there.

But in Scotland, for example, many rural properties have 700mm-thick stone walls that retain heat really well. The EPC, however, will class the wall as solid, scoring below an insulated cavity wall, even though it may actually perform better.

And when it comes to cavity walls, an EPC will simply rate whether it’s insulated or not, taking no account of the relative efficiency of the materials used. Neither does the EPC take account of embodied carbon – the difference between wood fibre, for example, which locks up carbon, and plastic-based foam insulation which has a far larger carbon footprint.

Of even greater concern is the unwitting potential to cause real damage in a bid to gain a better EPC rating. How a building was originally constructed will determine how moisture moves through its walls, floor and roof. Install the wrong type of insulation and it can result in huge problems with damp, condensation and worse. I’ve seen badly installed insulation cause dry rot, with devastating consequences. Getting expert advice is key.

There is no doubt that creating a residential sector that produces as few carbon emissions as possible is of the utmost importance. Finding a sharper tool to rate and promote the energy efficiency of our homes is an essential part of the challenge.

• For more rural views and advice, see the latest edition of Aspects of Land

Further information

Contact Ryan Timpson

Savills Rural