In Focus: Energy performance certificates (EPCs) and listed buildings - decarbonising historic buildings

Thinking of spending £50 on draughtproofing your house? Or £50,000 on a heat pump, replacement triple glazing, and wall insulation?

CLA member surveys suggest that most heritage and listed building owners want to decarbonise their buildings, and the right measures can make a lot of sense: you can nearly always achieve some combination of lower bills, greater comfort, and planet-helping carbon impacts than your starting point, and in a way that pays financially, so this should be worthwhile.

What actually happens, unfortunately, is often different: most building owners give up, because achieving this in practice – especially for listed buildings – can be much more difficult than it should be.

The two key obstacles are (i) knowing what to do, and (ii) government regulation, especially energy performance certificates (EPCs); and planning/listed building consent (though this is outside the scope of this article).

This is an area full of misinformation, some of it of course from those (like replacement window salesmen) with products to sell; but much of it from EPCs, the very tool which was supposed to solve this problem.

There is however a wide consensus among those who have an understanding of historic buildings, who do not have products to sell, and (unlike EPCs) take full account of actual financial costs and benefits.

It is best to take a holistic, ‘whole-house’ approach, especially if you are contemplating expensive measures or the house is dilapidated or damp, in which cases appropriate professional advice is essential. But in all cases it is vital to identify and adopt the right measures, and avoid the wrong ones. Obviously this varies from building to building, but usually you can draw up a list, with the most effective, cost-effective, and least-risky first, and the least cost-effective or most risky at the end.

Some actions may often be ‘no-brainers’ – effective, cost-effective, and low-risk. These are likely to include:

• behavioural change (closing curtains, reducing heating in less-used rooms, etc)
• draughtproofing windows, doors and floors (maintaining sufficient ventilation) – ignored in EPCs, but highly effective and cost-effective
• loft insulation
• improved heating controls
• low-energy lighting
• DIY secondary glazing of existing windows

Other actions will depend very much on their costs and the circumstances of your building. These might include:

• carefully-specified works to address damp (which makes buildings colder)
• expensive specialist secondary glazing of existing windows
• heat pumps
• solar photovoltaic and/or thermal
• floor insulation

However, there is a third list of measures you should consider only with great care, because they are less cost-effective, and/or cause net harm in carbon terms, and/or carry serious risks for the building and its occupants (and also usually require listed building or planning consent, and are less likely to achieve it). These include:

• solid wall insulation (which, though recommended in almost all EPCs, is expensive and carries a substantial risk of damp and health problems)
• double- or triple-glazed window replacement (which has a high financial cost, high carbon costs, and a relatively short life).

EPCs unfortunately do not much help with this. Under an EU directive, they became compulsory in 2008 for buildings being sold, marketed or let: it is usually unlawful to market, let or sell a building without first obtaining an EPC, and there are fines for non-compliance. There are some exceptions: essentially (the detail is complex) these are pre-2008 lettings; buildings occupied under a licence (like most holiday cottages); buildings without roofs/walls; buildings not expected to be heated; places of worship; temporary buildings; and (as below) many listed and other heritage buildings.

An EPC puts the building into an ‘energy performance’ band ranging from G (‘worst’) to A (‘best’), suggests a list of recommendations which might achieve better ‘energy performance’, and also suggests an EPC band the property might reach if all those works were carried out. EPCs involve a physical inspection by an accredited EPC assessor, but are usually easy to organise (preferably via personal recommendation, or via www.gov.uk or Local Surveyors Direct) and cost from about £60.

In theory, EPCs should be very helpful, an inexpensive and easy-to-organise tool which tells you what’s wrong and how to fix it. In practice, although a decade of lobbying by the CLA and others has improved them somewhat (there may be some further improvement in mid-2025), they remain part of the problem. Firstly, the Standard Assessment Procedure (SAP/RdSAP) measurement methodology which underlies EPCs is inaccurate, often measuring buildings (especially pre-1919 buildings) as ‘worse’ than they are. Secondly, it still often mis-rates some interventions like wall insulation as more effective than they actually are, but other interventions like draughtproofing as less effective than they actually are. Thirdly, EPCs still deliberately iignore the high negative carbon impacts and short lives of many of their recommendations, like double glazing. Fourthly, some EPC recommendations (especially wall insulation) can carry considerable risks, ignored in the EPC, to buildings and to occupier health. Fifthly, EPCs usually greatly understate the financial costs of interventions.

Overall, unfortunately, EPCs are thus unreliable (the government’s EPC Action Plan said that 97% of consultees thought EPCs inaccurate), and their recommendations are often misleading at best or physically-damaging at worst.

Where you are the owner-occupier, an EPC is only compulsory if you decide to sell or market the property, and even then the aim is simply to provide information to a purchaser – there is no obligation on you (or a purchaser) to do anything. That may change in future, perhaps with (say) council tax or stamp duty surcharges for buildings in ‘bad’ EPC bands, but probably not quickly.

This does not mean you should do nothing – it may well make sense to implement appropriate measures from the list above, to make the building warmer, or cheaper to heat – but that is not compulsory.

Let buildings are very different. Under the Minimum Energy Efficiency Standards (MEES) Regulations, it is already in most cases a criminal offence to let them unless they have an EPC rating of E or ‘better’. If you do not comply, fines (per breach and per property) can be substantial, and enforcement, previously rare, is being stepped up.

There are exceptions which fall outside MEES. The detail is complex, but the main point is that buildings which do not require EPCs, as above, are outside MEES. This can often – as explained below – exclude listed and heritage buildings.

If you do fall within MEES, it also currently has a number of specific exemptions, though you need to formally register them, and repeat that every five years. They are complex, but essentially they can make you exempt if the cost of compliance would exceed a cost cap (currently £3,500, but likely to increase, perhaps to £10,000 or more); or where planning or certain other consents are refused; or where the tenant objects; or where a chartered surveyor certifies either that compliance would significantly devalue the building, or that solid wall insulation would damage it; or where implementing all the EPC recommendations still does not take you to band E.

It is vitally important to note that the government has announced that the minimum EPC requirement will increase to band C byin 2030. Details remain unclear, and there may also be other changes, including to the cost cap as above, and perhaps to exemptions. This will make MEES compliance vastly more difficult in future, and increase the risk of harm to buildings and occupiers. EPC band E is often relatively achievable, at sensible cost; band C is far more difficult, and probably unachievable for many buildings (especially until all the current problems with EPCs have been addressed). The cost of works would often be very high (far more than current EPCs suggest).

It is not surprising that MEES, and many other UK Government initiatives which reduce the viability of renting property, are causing owners to sell rental properties, reducing the supply of rental properties for local people who cannot afford, or do not want, to buy.

There is no exemption, as such, for listed buildings from the EPC or MEES regulations. Crucially and sensibly, however, there is a qualified exemption from the requirement to have an EPC for listed buildings and (importantly) other heritage buildings, intended to exempt works which would harm the heritage significance of the building.

Essentially, you first obtain an EPC, then carry out any EPC recommendations which would not damage heritage significance. You then obtain another EPC. Provided the new EPC contains only recommendations which would damage heritage significance, you are then exempt from the requirement to have an EPC (even if you already have one or more EPCs). This may sound confusing (you probably need one or more EPCs in order to demonstrate that you do not need an EPC), but demonstrating that you do not need an EPC then puts the building outside the scope of the EPC and MEES Regulations, so you do not need to comply with MEES, and thus do not have to carry out damaging works, or to go through the hassle and cost of registering MEES exemptions. You can take all these decisions yourself (though an opinion from a chartered surveyor or accredited heritage consultant might be important as supporting evidence), but it’s very important to follow a logical process, and document it carefully, so you can be ready with clear evidence if an enforcement officer arrives.

It is important however not simply to view MEES exceptions and exemptions as a ‘get out of jail free card’. You will have to carry out any works which do not damage heritage significance (unless they fall within the specific MEES exemptions listed above). More importantly, there is of course no virtue in having freezing tenants, and it may well make sense to implement appropriate actions from the lists above, to make the building warmer, and more lettable if the current tenant leaves.

Note: This article applies to residential buildings in England and Wales. It provides only a simplified picture, and it is important to use the UK Government guidance on MEES and EPCs, especially The Domestic Private Rented Property Minimum Standard: Guidance for landlords and Local Authorities…, including the technical advice in Chapter 3. This is available here.

If you are a CLA member, you will have free access to two CLA Guidance Notes, a brief guide Domestic EPCs and MEES, and the much more detailed Reducing heating costs and decarbonising heritage, which includes a long section on which works potentially make sense, and which don’t. These can be found here.