How retrofitting your country house could save you more than £50,000 a year — even if it’s listed

When the listings system was introduced immediately after the Second World War, to salvage important buildings damaged by bombing, the conservation ambitions — while laudable — came with their attendant complications. Up until that point, houses evolved with the generations, with each one carrying out significant overhauls every 30 years or so. As soon as a property was listed, making significant interventions became significantly more challenging.

Nearly 80 years have passed since those first statutory lists were compiled and frustrations with the limitations imposed are becoming increasingly apparent. In a report titled Retrofit or Ruin published in February 2026, the property company Grosvenor claimed that England’s 350,000 listed buildings today face becoming ‘uninhabitable, unaffordable and ultimately redundant’ unless the government simplifies the planning system to make it easier to upgrade the buildings.

Making a standard house more energy efficient is relatively simple. It requires draught-proofing, double-glazing windows and doors (or adding secondary glazing) and adding insulation to lofts and under or between floors. Then it’s a matter of installing heat pumps instead of boilers — air source heat pumps (ASHPs) are often preferred as they require less installation and cost less than ground source (GSHPs) — alongside a mix of solar panels, hidden from view either on a roof or in a neighbouring field, and integrated battery storage for even distribution throughout the year as demand requires.

Until recently, many thought that applying this sort of approach to a historic house, and especially a listed property, was next to impossible or eye-wateringly expensive. That’s no longer true, says Bean Beanland, an energy consultant who has worked in the renewable energy sector for nearly two decades. Having advised on many listed and historic properties, his attitude is that if an old house can be heated with a conventional boiler, it can be heated with a heat pump.

Pointing a finger at the ‘slow, complex and inconsistent’ rules governing listed properties, Grosvenor’s research calculates that planners in local authorities spend 4,000 working days each year looking at what they term low-risk measures on listed properties such as insulation and heat pumps. It calls for the introduction of a national listed building consent order — akin to the permitted development rules that exist for non-listed properties — to grant automatic consent for any proposals to make homes warmer and more energy efficient to run.

Garden designers Isabel and Julian Bannerman (above) bought their house in 2019 and were determined to make it environmentally friendly. ‘My husband was very sceptical that it could work — along with all the builders,’ says Isabel. ‘But I got the bit between my teeth. There was so much that needed doing to the house that I knew it was a good time to make it warm and comfortable at the same time.’

The main house (above and below) is largely Elizabethan with large leaded windows, so all the advisers quickly assumed an air-source heat pump wouldn’t work. 'Luckily,' says Isabel 'I was very stubborn and my son, who is a quantum engineer, encouraged me to persevere. I kept explaining to all the experts and advisers that we are old-fashioned country folk who do not spend our days on a laptop in a T-shirt and not much else. So, we didn’t want the house to be hot, but we are getting older and we wanted it to be a dry house.’

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The solution was to adopt two approaches: the majority of the property and a cottage in the grounds are now run on an ASHP and have underfloor heating, but a wing is still reliant on an oil-fired boiler and cast-iron radiators, although they hope to change this. They weren’t allowed to double-glaze the Tudor and medieval windows; instead, they insulated anything they could using Glapor, a type of recycled foamed glass gravel insulation and, where possible, limecrete, a flooring system that breathes.

The system is powered by an 8kW Daikin ASHP alongside 27 solar panels positioned in a field and two Tesla batteries — the greatest expense — which sit in a garage. Once it’s installed and working properly, her advice is not to touch the system — don’t adjust rooms by turning thermostats down, just leave everything ticking over.

The electric AGA is the fly in the ointment, says Isabel. ‘But it is affordable for a big old manor house in a way that I could barely have imagined at my most optimistic. The capital outlay was scary, but it will be paid off by the end of the decade.’

Stefan Pitman, managing director of Dorset-based Spase Architects & Surveyors, was responsible for retrofitting Athelhampton, a 25,000sq ft Grade I-listed Tudor manor house in Dorset (above).

The property had previously cost around £55,000 a year (in 2019 prices) to run on LPG boilers, heating oil and a diesel generator. When the new owner bought the house, he embarked on an ambitious project to remove the reliance on fossil fuels. Today it costs about £500 a year to run, mostly made up of standing charges.

For the main house, they installed 15 high-efficiency ASHPs and solar power with storage batteries. Timing played a part: the project came together just as the next generation of ASHPs had become available, which were more efficient to run and could generate a higher degree of heat — something Stefan describes as a ‘game-changing’ moment in the process of retrofitting old country houses.

Inside the main house, the team looked at each room individually. ‘We insulated wherever we could, in between floors and between rooms. It helped that the whole house had to be re-wired and replumbed and that the old heating system was completely defunct — often it was colder inside the house than it was outside.’

The cost was high, but at the time the return on investment was seven years, and even today, Spase believes that it would be about 10 years. The team at Athelhampton calculated that to retrofit an average-sized family home in Dorset with an ASHP, new radiators and hot water storage could cost around £12,000, saving around 12,000 kWh of gas annually.

‘Yes, it does require some investment, but the results are worth it,’ says Stefan. ‘You can significantly reduce or even eradicate heating and electricity bills, provide a better environment for the building and its contents and reduce carbon emissions.’

An evolution in domestic heating

Sixty years ago, in the pages of Country Life, it wasn’t uncommon to see ‘central heating’ listed on the property advertisements alongside other attributes such as the number of bedrooms and garden acreage. ‘It’s so long ago that everyone’s lost sight of the cost of installing it, but just think about how much was involved at the time,’ says Bean. ‘All the pipework and radiators had to be installed from scratch, which required pulling up floorboards and taking plaster off walls.’

He sees the introduction of heat pumps as the next step in the evolution of how to heat homes. ‘For historic properties, the way that heat pumps deliver heat — that is, at a constant temperature — is actually much healthier for the furniture, for the artwork, for the fabric of the building and for the occupants.’

Tim Moulding, of Moulding, specialist country house builders, believes the challenge of how to retrofit historic properties has to be resolved. ‘Electricity from renewable sources seems to be the future and heat pumps are the solution to convert this electricity into heat and hot water.’

The best time to switch

In the absence of other drivers, such as a quest to lower carbon emissions, the best time to switch is when the current boiler comes to the end of its life. ‘And if that’s before owners have done all the double or secondary glazing and insulated the loft, that’s ok,’ says Bean.

He recommends taking advice from experts about how to bring the flow temperature down progressively and start with the worst-performing room of the house. 'The best way is to have a heat-loss survey (see below) done and then you have all that information at your fingertips. Then you can refer to it so that when you’re redecorating a room, you can upscale the radiator at the same time in preparation.’

Steps to switching

Eliminate draughts first. By prioritising this, energy demand for heating can be lowered. Add draught-proofing strips around the window frame or on the sills. These can be either self-adhesive foam strips, which have a limited lifespan but are easy to install or metal strips with brushes attached.

Make improvements to all outside doors, too — even adding an escutcheon to door locks will help. Use shutters at night; these are excellent at keeping draughts out.

Commission a heat-loss survey to understand how the house performs. If the house is listed, find someone who has experience working with old buildings and bear in mind that this doesn’t necessarily need to happen in the winter months.

Whether or not the existing heating and hot water system requires replacing will depend on whether the pipe distribution and heat sources — be they radiators or underfloor heating — can generate sufficient heat at the lower incoming temperature that heat pumps generate. This can be trialled over a cold winter.

Where necessary, establish a plan of upgrading radiators or consider installing underfloor heating under limecrete floors, if possible.

Look at replacing or upgrading windows. Historic England has become more accommodating in recent years. Slimline double glazing can sometimes be retrofitted into existing sashes and secondary glazing is often permitted. Vacuum-insulated glazing is the most recent innovation in insulated glazing. It consists of two glass panes with a 0.1-0.3mm vacuum gap rather than gas in traditional double glazing, which virtually eliminates the heat transfer.

Insulate where possible using breathable materials that manage moisture, such as hemp-lime plaster, sheep’s wool or wood fibre boards.