‘It cost us £60,000, but our flint Victorian cottage is now the model of energy efficiency’

Deborah Grubb and David Pratley loved their beautiful flint Victorian cottage with views over the South Downs but it was freezing in winter, with an energy performance certificate (EPC) of E. “An engineer friend once referred to it as ‘a thermal nightmare’,” says Ms Grubb.

So the couple, who are in their mid-seventies, overhauled it completely, turning the place into a model of energy efficiency that was also equipped to suit them into old age – spending more than £60,000 on eco measures in the process.

Sustainable architects Baker Brown insulated the loft and, at a cost of £14,000, added insulation and weatherproofing to the first floor. Then came the installation of a new £30,000 heating system, comprising an air source heat pump, a high-efficiency water tank, new plumbing and underfloor heating. Replacing the windows on the first floor with slimline double glazing cost £12,000, while solar panels cost about £8,000.

The three-bedroom, three-bathroom house now has the top EPC rating of A and negative carbon emissions because the property uses less energy than the solar panels generate. 

“We’re delighted and we have a stunning home, which we love, and we can now stay here as long as possible,” says Ms Grubb, who was advised on the renovation by Future Proof My Home.

While many homeowners would like to make their homes more energy efficient and much cheaper to run ahead of winter, the cost of installing measures such as solar panels and heat pumps is prohibitive, particularly amid the cost of living crisis and rocketing mortgage rates.

According to energy efficiency experts the Energy Saving Trust, the average domestic 3.5kWp solar PV system costs around £7,000. The outlay for an air source heat pump is about £14,000, while ground source heat pumps typically cost around £28,000, but this can rise to £49,000 if you need to dig a borehole.

However, research by David Fell, of Hamptons estate agency, offers some good news. His analysis looked at properties’ EPC ratings, which rate a home’s energy efficiency from A (best) to G (worst). He then looked at what impact making different individual energy-efficient improvements had on moving the building up to a better ranking.

“What really stood out was the importance of doing the basics first – and these are often the cheapest things to do – to make a home as energy efficient as possible,” Mr Fell says.

“Things like insulation and energy efficient lighting can make big improvements. Whereas costlier items, such as solar panels and triple glazing, tend to be fitted to homes that are already reasonably energy efficient.”

To come to these findings, Mr Fell looked at the energy efficiency measures installed in homes with the best EPC ratings of A to C. Of these properties, 79pc had an air source heat pump, 33pc had solar panels to heat water, 43pc featured low energy lighting throughout and 52pc had triple glazing. Some 51pc included cavity wall insulation, while 26pc were double-glazed.

Mr Fell then looked at a property’s chance of moving up an EPC band for each eco improvement. By installing up to 100mm of loft insulation, for example, 79pc of households moved into a better EPC band.

Quantity surveyor Tim Phillips, who is an expert for the Homebuilding & Renovating Show, says insulation makes a huge difference. “You can have the best boiler or heat pump in the world, but if the property isn’t properly insulated, you’re losing all the heat.”

Loft insulation is one of the easiest and cheapest energy efficiency measures to install and could reduce your energy bills by up to £315 a year, according to the advice group Which?

If your loft is easy to access and has no damp or condensation issues, you can probably do it yourself; it costs about £28 for a 100mm-thick roll, which is designed to cover about 8.3m2. The recommended thickness for loft insulation is 270mm – you can top yours up to this level if it falls short.

Even fitting an insulation jacket to your hot water cylinder can help, according to Tom Edmunds, from the heating experts Wunda Group. “This could save you £35 a year in heating costs as well as 115kg of carbon emissions,” he says.

Energy-efficient lighting also has a big impact on cutting bills and improving your EPC rating – the Hamptons research found that going from zero to full low-energy lighting meant 77pc of homeowners moved up an EPC band.

If you replaced all the bulbs in your home with LED lights, you could save £65 annually on your electricity bills and reduce carbon dioxide emissions by up to 50kg a year, equivalent to the carbon dioxide emitted by driving your car around 145 miles, the Energy Saving Trust says.

However, the first step towards cutting fuel bills and improving your EPC rating is to go back to basics and look at the fabric of your home, according to Alexander Macfarlane, of the building consultancy team at Strutt & Parker estate agency.

“It’s a case of good routine maintenance such as making sure gutters aren’t leaking and that there aren’t any draughts coming in through the windows,” Mr Macfarlane says. 

“If you have an open chimney, consider blocking it with a chimney balloon – but don’t forget to remove it during the warmer months to aid ventilation and reduce the chance of damp. Even thermal-lined curtains make a big difference, as I found in my own home.”

Such measures are particularly pertinent for period or listed properties where adding measures such as double glazing is difficult. “Secondary glazing can also be fitted to windows in historic buildings to improve efficiency but without any loss of character,” Mr Macfarlane adds.

Other efficiency measures require a much higher financial commitment; however, Nicholas Gibson, of Savills estate agency, says: “The smaller improvements like low energy lighting and appropriate insulation can generate savings, allowing owners to save more to implement the bigger improvements down the line.”

There are also some schemes available, such as ECO Plus, which provides grants for loft and cavity wall insulation. The Government has reduced VAT on energy efficiency installations, including solar panels, insulation and heat pumps, to 0pc until 31st March 2027.

Insulating cavity walls can make a big difference to your EPC rating – Hamptons’ research found that 82pc of properties that installed it moved up to a better band.

If your house was built after the 1920s, it is likely to have cavity walls, which can be insulated by injecting insulation material into the cavity from the outside. A specialist company will drill holes in the outside walls, inject insulation – usually either mineral wool or polystyrene beads – through the holes and then seal them with cement.

For a semi-detached house, the typical cost is £2,700, which could shave about £300 off your energy bill every year, the Energy Saving Trust says.

However, Mr Phillips warns against the use of cavity beads. “They have been found to cause damp problems and are a no-go in Wales and in certain parts of England that get excessive rain exposure,” he explains.

Instead, Mr Phillips installed external wall insulation on his own home, a five-bedroom 1860s house in Merthyr Tydfil, south Wales, which is stone-built and has no cavities. “External wall insulation costs £80-£110 per m2 and, if installed correctly, does not cause damp or adversely affect the look of the property,” he says.

EPCs are confusing and often misunderstood, but it is a legal requirement to have one if you are selling a property or letting one out.

Whereas 80pc of new-builds have an EPC rating of A or B, only 3pc of existing homes achieve these ratings, according to Philip Harvey, from the buying agency Property Vision.

“Technology exists to significantly mitigate carbon emission from a period property, but it’s not a cheap exercise,” Mr Harvey says. “Refurbishment costs are around 15pc higher than traditional methods, but sustainable interventions will reduce running costs, usually with a payback time of less than 12 years, and can also enhance a property’s value.”

Research by Knight Frank estate agency comparing the EPC certificates of 30,000 dwellings that improved their home energy performance in the five years pre- and post-improvement estimates that the average cost spent improving a dwelling previously rated EPC band D or below to at least a band C was £9,260.

Those homes that had moved from a D to a C rating added an additional 3pc to their value over and above local house price growth. Properties moving two bands from an E to C saw an average price uplift of 8.8pc, and those going from F or G to C gained an additional 19.6pc.

Indeed, given the increased cost of energy and growing awareness of climate change, EPC ratings are now scrutinised carefully by property buyers.

Louise Ridings, from Stacks Property Search, adds that buyers are getting “twitchy about ratings below a C, as they’re concerned about the ability to resell the property, so taking action on a low EPC rating is a priority.”