The UK needs more houses. Demand is outstripping supply and it’s driving up prices, making affordable housing harder to come by. That’s just one of the reasons behind the government’s intention to build 1.5 million new homes over the next five years.
But as of 2025, the UK’s Future Homes Standard comes into effect, which requires all newly built homes to be more energy efficient and produce 75–80-per-cent fewer emissions than those built under the 2013 regulations.
Builders plan to meet the new regulations by orienting homes to maximise natural light, using low-carbon materials like cross-laminated timber (which captures carbon dioxide – CO2 – while it grows, emitting less CO2 than concrete to produce), and integrating renewable energy systems such as solar panels and heat pumps.
Advanced ventilation systems and airtight constructions will also help new houses minimise energy loss while maintaining indoor air quality. Rainwater harvesting systems and recycling greywater (water from baths, showers, sinks and appliances such as washing machines and dishwashers) will further help with sustainability.
But what if you already have a house? One that’s a little older, but could potentially benefit from some new additions to make it more energy efficient, more economical to run, more environmentally friendly and more healthy to live in?
Whether it’s lowering bills or doing your bit for the planet, retrofitting your home – upgrading your existing building’s structure and systems – can have a positive effect. Poor insulation, outdated heating systems and damp issues not only waste energy, but can also lead to respiratory illnesses and higher household expenses.
This is a particular problem in the UK, which has some of the oldest and leakiest housing when compared to Western Europe, and where homes account for 15 per cent of our greenhouse gas emissions.
Globally, real estate accounts for 40 per cent of emissions and within this figure, only a third comes from building the homes themselves; the rest is caused by leaky, poorly insulated houses powered by fossil fuel boilers.
The health implications don’t stop there; it’s thought that more than 14 per cent of childhood asthma cases can be linked to living in damp or mouldy homes.
Governments have set a host of energy efficiency standards for new builds, but this leaves a gap that requires a mammoth retrofitting effort.
According to Gregory Dewerpe, co-founder of Noa, a venture capital firm backing technology to accelerate the decarbonisation of the built world, “we need to spend $100 trillion (£79 trillion) by 2050 just to retrofit our existing stock of building to get to net zero.”
Retrofitting isn’t just about improving your home’s resale value. It’s the best way to tackle rising bills, alleviate fuel poverty and future-proof your housing and health.
“The beauty of retrofitting is that you don’t have to do everything up front,” says Dewerpe.
“You can start the journey with insulation and then, maybe next year, if you have a bigger budget, you opt for a heat pump, and so on. It’s not all or nothing and there’s a solution for anyone with any budget. The key is just to pick a project and start somewhere.”
What follows are tips on where you can start retrofitting your home, with practical advice to turn it into a smarter, healthier and greener place to live.
1. Insulation
Before rushing out to invest in solar panels or heat pumps, Gerald Charles, head of retrofit at the Centre for Sustainable Energy, advises prioritising insulation and draught-proofing because “a home that leaks heat wastes energy, whether it’s renewable or not.”
Insulation stops heat escaping through walls, roofs and floors, reducing the need for constant heating. Depending on the type of walls your home has, mineral wool, polyurethane foam, beads or rigid board insulation all help to fill the gap between outer and inner walls, trapping air and minimising heat loss.
Homes with solid wall insulation can cut heat loss by 30 per cent, while loft insulation alone can save up to £380 annually. Both contribute to a smaller carbon footprint, and a well-insulated home better regulates humidity and prevents damp.
External insulation involves fixing a layer of insulation to the wall before covering it with plasterwork or cladding. It comes with higher costs – around £11,000 for a three-bed home vs £7,500 for internal options – but it brings the added benefit of filling cracks in the brickwork, which also reduces draughts.
Internal wall insulation is done by fitting insulation boards to your walls, or by building a stud wall filled with insulating material.
“If you can only afford to do one thing, prioritise insulating your loft with 270mm insulation, as a minimum,” says Charles. “Loft insulation prevents heat loss through the roof to cut energy bills by roughly 25 per cent, making it an environmentally friendly and cost-effective strategy.”
Cheaper and less disruptive alternatives include insulation made from latex foam that sits on top of your internal walls and floors, and can be painted or carpeted over. Or if you prefer a more high-tech option, infrared ceiling paper.
It works on the same principle as infrared panels (an alternative to traditional radiators) by emitting infrared radiation to heat the objects in a room – the walls, furniture and people – instead of the air. But rather than a panel mounted on a wall, it relies on a special type of wallpaper, which is stuck to the ceiling and contains an infrared heating element.
Infrared ceiling paper uses less energy than a traditional radiator system and is comparatively easy to install, but it can’t provide you with hot water and can be expensive to run, given that gas is considerably cheaper than electricity.
2. Radiators and pipes
Radiators and pipes are often overlooked in retrofitting projects, but offer significant energy-saving potential. Radiator reflectors use a foil-like, low-emissivity material to stop up to 95 per cent of heat escaping through your walls. It could save you up to 71kg (156lbs) of CO2 and £40 per year on energy bills.
Older boilers can benefit from insulation, with boiler jackets costing around £30 from hardware stores, while foam pipe lagging reduces heat loss in pipes for around £1–£5 per metre.
Beyond insulation, smart thermostatic radiator valves (TRVs), such as the Tado Smart Radiator Thermostat, allow precise control of individual room temperatures, cutting energy usage by up to 28 per cent.
Technically, the Tado system adds to your energy use, but its manufacturers claim it uses approximately 0.7W, which adds up to 6.21kWh, or less than £2, per year.
Smart devices, such as Google’s Nest or the Hive thermostats, use machine learning to adjust heating and cooling accordingly. Or you can install a smart meter (above) to help you monitor and manage your energy use.
Smart energy devices cut energy bills by an average of eight per cent, although this can change a lot depending on how you use the insights they provide.
3. Ventilation
Proper ventilation is key to preventing the damp and mould caused by excess moisture from cooking, showering or drying clothes. Poor ventilation traps pollutants like dust, allergens and volatile organic compounds (VOCs) indoors, which can trigger respiratory issues and a variety of allergies.
Make sure extractor fans are clean and in good working order, and keep trickle vents on windows unobstructed. Smart extractor fans adjust airflow based on humidity and VOC levels, while natural air filters use reindeer moss, coconut fibres and activated carbon to filter air without electricity.
Other options include dehumidifiers, purifiers and air monitors. Dehumidifiers remove excess moisture from the air and are particularly good at preventing damp, mould and condensation.
Air purifiers use fans and filters to draw and clean air making them ideal for households with pets, smokers or people with allergies. High-efficiency particulate air (HEPA) filters capture microscopic particles, and activated carbon layers trap and get rid of odours and VOCs.
If you only want to monitor air quality, but not filter it, consider the Birdie Air Monitor (above). It looks like a bird on a perch, but drops down when air quality is poor as a sign that you might need to open a window. It’s inspired by the canaries used in coal mines to warn miners about the build-up of toxic gases.
At the top end of the spectrum, Mechanical Ventilation with Heat Recovery (MVHR) systems exchange stale indoor air for fresh outdoor air while retaining heat. They’re increasingly common on new builds and cost around £6,450 to install, but can cut heating costs by a quarter while improving air quality.
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4. Heat pumps
Heat pumps are an energy-efficient alternative to gas- or oil-based heating in winter and air conditioning in summer. Estimates suggest they’ll reduce global CO2 emissions by at least 500 million tonnes by 2030 – the same as the annual CO2 emissions of all cars in Europe today.
Heat pumps take heat from the air, ground or water – even in freezing temperatures – and move it indoors for heating. This energy is captured by a refrigerant, a special fluid with a low boiling point that circulates through coils in the system.
As the fluid absorbs heat, it turns into a gas, which is compressed and sent through coils inside your home’s heating system. In warmer months, the process can be reversed to transfer the thermal energy outside.
Air-source heat pumps, which take heat from the air, have installation costs averaging £14,000. Ground-source systems average £28,000 due to the need for buried pipes (hybrid systems combine heat pumps with traditional boilers).
The UK government’s Boiler Upgrade Scheme can help offset some of these costs.
Again, these systems add to your energy usage, but produce an average of 4kWh of heat for every 1kWh of electricity consumed. Not all homes are suitable for heat pumps, but there are questionnaires you can fill out to check.
5. Solar panels and battery storage
It’s one thing to make better use of the energy you’re already using, but generating and storing your own from renewable sources, such as solar, is an approach that can lower bills and reduce carbon footprints.
Solar panels convert sunlight into electricity, even in low-light conditions, through photovoltaic cells made from semiconductor materials. “When sunlight hits the surface of a solar panel, the energy from the light particles – known as photons – excites electrons within the cells,” explains Dr Nicola Battey, director of sustainability at Hometree.
“This movement of electrons creates a current, which is sent to an inverter to make it suitable for powering household appliances and lighting.” Once converted, this electricity is either used or sent back to the grid for other uses.
A typical domestic solar installation costs around £7,000, but can save £600–£700 a year on bills. Reports suggest solar panels can add up to £2,000 on the value of your home, while also reducing carbon emissions by 1.3–1.6 tonnes per household per year.
If you pair solar panels with a home battery storage system, such as the Tesla Powerwall or Moixa Smart Battery, the excess energy can be stored for later use or sold through the Smart Export Guarantee (SEG) scheme.
Prices for these battery systems range from £3,000–£6,000, but can slash bills by as much as 85 per cent while cutting your reliance on grid electricity, which often has a higher carbon footprint.
When you add a heat pump to the mix, these savings rise to more than £3,000 a year. “There’s no one-size-fits-all approach to retrofitting your home and even homes that look similar may have different needs due to their location, condition or previous modifications,” says Battey.
For solar installations, she says you must consider your roof type (whether it’s pitched or flat, for example), the direction your home faces, energy usage and potential planning restrictions.
“South-facing, pitched roofs are generally better for solar panels as they can be angled to capture the most sunlight throughout the day. Flat roofs can still work with systems to tilt the panels toward the Sun, as can east- and west-facing roofs. North-facing roofs are generally unsuitable.”
The Energy Savings Trust has a solar calculator if you want to learn more.
6. Draught-proofing
Draught-proofing is one of the simplest and cheapest ways to improve your home’s energy efficiency, saving around £125 annually. Draughts from doors, windows and chimneys let cold air in and warm air out, forcing heating systems to work harder. You can’t block them all up though, because then you’ll have ventilation issues.
Simple fixes include metal or plastic strips with brushes for windows and letterboxes, keyhole covers and brush strips under external doors. Larger sources of heat loss, such as chimneys, can be draught-proofed with a professionally installed chimney cap or specially made woollen plugs, balloons or even an old pillow in a bin liner.
Smaller gaps between floorboards and skirting boards can also be sealed with flexible silicone-based fillers.
7. Sleep
When it comes to improving our health, few things have as much of an effect on us as a good night’s sleep. It allows our bodies and minds to repair and recharge, while poor sleep has been linked to stress, anxiety, and conditions like hypertension and diabetes.
The ideal conditions for sleep are dark, quiet and cool. Blackout blinds or curtains are a worthwhile investment to block out light, while portable blackout blinds with suction cups offer a more flexible option.
Smart lighting systems allow you to adjust light intensity and colour temperature if you want to create a calming atmosphere.
‘Sunrise alarms’, which incorporate lights that brighten progressively to mimic the sunrise, can also help wake you up with less of a shock, allowing you to balance your circadian rhythm.
In terms of cutting out noise, insulating and draught-proofing your home has the double benefit of lowering ambient noise and absorbing external sounds. Soft furnishings such as rugs and heavy curtains made from wool or velvet can dampen sound, as can rearranging furniture to buffer some of the noise from particular walls or windows.
For more significant noise reduction, double or triple glazing is expensive, but will reduce noise levels and heat loss. More advanced options, such as smart windows with noise-cancelling technology, are growing in popularity, although these are still quite rare. Companies like DeNoize and Intelligent Glass offer various options, however.
Finally, regulating your temperature is key to a comfortable night’s sleep and switching to lighter duvets, fewer clothes or breathable fabrics are easy ways to cool down.
Alternatively, smart mattresses like the Eight Sleep Pod 3 or iSense Hybrid Premier both offer precise comfort controls. These mattresses can track sleep metrics via apps, adjust firmness or temperature, and vibrate gently to wake you up in the morning.
About our experts
Gregory Dewerpe is the co-founder and managing partner of Noa venture capital firm, which backs technology to accelerate the decarbonisation of the built world.
Gerald Charles is the head of retrofit at the Centre for Sustainable Energy. He helps people to lower their energy bills and supports retrofitting measures in the South West of England.
Dr Nicola Battey is the director of sustainability at Hometree.
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