You do not need to spend thousands to start cutting your energy bill. These five changes cost little or nothing. The savings are Energy Saving Trust figures for Great Britain; your own will depend on your home and how you use energy.
1. Draught Proofing
Cost: around £250 professionally for windows and doors; less if you do it yourself
Typical saving: around £55 a year for windows, doors and floors
Gaps around doors, windows, letterboxes, floorboards and loft hatches let warm air out and cold air in. Self-adhesive strips, brush strips, letterbox covers and gap filler are simple DIY jobs. If you have an open chimney you do not use, draught proofing it could save around another £45 a year.
Important: never block ventilation that is there on purpose, such as trickle vents, air bricks or extractor fans.
2. Get the Most From Your Heating Controls
Cost: free to adjust; around £600 for a programmer, thermostat and radiator valves if you have none
Typical saving: around £100 a year from installing heating controls; around £120 a year from turning the thermostat down from 22°C to 21°C
A programmer sets when the heating comes on, a room thermostat sets the temperature and thermostatic radiator valves (TRVs) control each room. Set the thermostat to the lowest temperature you are comfortable at — for most people between 18°C and 21°C — and heat rooms only when you use them. Smart thermostats add app control and scheduling.
3. Switch to LED Bulbs
Cost: depends on how many bulbs you replace
Typical saving: around £45 a year from replacing the remaining halogen spotlights in a home
LEDs use far less electricity than halogen bulbs for the same brightness and last much longer. Match the fitting type and choose by lumens (brightness) rather than watts. The Energy Saving Trust notes that app-controlled “smart bulbs” are not likely to save energy on their own. Switching lights off when you leave a room saves around £7 a year.
4. Top Up Your Loft Insulation
Cost: around £500–£800 professionally; much less for materials if you do it yourself
Typical saving: around £13–£35 a year from topping up 120mm to 270mm; £140–£360 a year if the loft has no insulation
If your loft already has some insulation, laying another layer of mineral wool across the joists to reach 270mm is a straightforward job in an accessible, damp-free loft. Do not squash the existing insulation, and keep eaves ventilation clear. If your loft has none at all, the savings are much bigger — see our loft insulation guide.
5. Check Your Boiler’s Flow Temperature
Cost: free
Typical effect: research by Nesta found turning the flow temperature down to 60°C improves boiler efficiency by nearly 4%
Condensing boilers work most efficiently when the water in the heating system runs cooler. On many combi boilers you can turn down the radiator (flow) temperature — not the hot water setting — and check the house still gets warm enough. The Energy Saving Trust advises treating bigger savings claims with caution, and this does not suit every system. If you have a hot water cylinder, keep stored water hot enough to control legionella bacteria, and ask a heating engineer if you are unsure.
Adding It Up
These savings do not simply add together — for example, draught proofing and lower thermostat settings both reduce the same heating demand. But a combination of free changes and a few low-cost measures can make a noticeable difference. For bigger savings, look at insulation or solar panels, and check our grants guide for help with costs.
Sources: Energy Saving Trust guides to draught proofing (May 2026), thermostats and heating controls (February 2026), lighting, quick tips (August 2026), roof and loft insulation (July 2026 fuel prices) and boiler flow temperature (May 2026). Last reviewed September 2026.