Home energy

Collect at least 12 months of electricity and gas, oil or other heating-fuel use. Record consumption in kWh where possible, not only cost. Costs change with tariffs; kWh makes one year easier to compare with another.

Look for:

• unusually high winter use;
• a high summer baseload;
• changes after a new appliance or heating setting;
• estimated rather than actual meter readings;
• electricity used during expensive time-of-use periods; and
• rooms that are cold despite high consumption.

A smart meter can make patterns easier to see, but the in-home display is not a substitute for understanding the tariff and annual bill. Check that the supplier is receiving readings and that day, night or export registers are recorded correctly.

1. Safety, damp and urgent repairs

Fix unsafe appliances, active leaks, defective flues, serious damp and structural problems first. Insulating a wet wall or covering a ventilation fault can make the underlying issue worse.

2. Low-cost controls and draught reduction

Use suitable heating schedules, thermostatic radiator valves and hot-water settings. Seal unintended gaps around doors, windows and service penetrations while keeping required vents open.

3. Insulation and building fabric

Consider loft, cavity-wall, solid-wall and floor insulation according to the construction. Check moisture risk, detailing and ventilation rather than choosing solely on quoted savings.

4. Heating and hot water

Once heat demand is understood, compare boiler optimisation, heat pumps, heat networks, storage heaters or other systems. Include emitters, controls, cylinders, standing charges and fuel storage.

5. Generation, storage and flexible tariffs

Solar panels, batteries, EV charging and time-of-use tariffs can reduce costs when they match the household’s demand. Model them after understanding the underlying use.

Get a shortlist for your home: what should you improve first? →

Loft and roof insulation

Heat rises into the roof space, making accessible lofts a common place to start. Existing material may be uneven, compressed or interrupted around hatches and eaves. Maintain ventilation paths and take care around wiring, downlights, tanks and pipework.

Cavity-wall insulation

Some homes with unfilled cavity walls may be suitable. Exposure, wall condition, cavity width and previous alterations matter. A survey should identify defects and explain the proposed material and guarantees.

Solid-wall insulation

Solid walls can be insulated internally or externally. These projects can materially change heat loss but are more disruptive and need careful moisture, junction, fire and ventilation design.

Floor insulation

Suspended timber floors may allow insulation from above or below. Solid floors usually involve more disruption. Air bricks and sub-floor ventilation must not be blocked.

Windows and doors

Replacement glazing can improve comfort, draughts and noise, but it may not be the first measure with the shortest financial payback. Repair, seals, secondary glazing and curtains may help where full replacement is unsuitable.

Loft insulation: what to check first →

Draught-proofing without blocking ventilation →

Cavity-wall insulation: suitability and risks →

Solid-wall insulation: internal or external? →

Floor insulation: timber and solid floors →

Warm air can hold moisture from cooking, bathing, drying clothes and breathing. When it reaches a cold surface, condensation can form. Insulation may warm surfaces, but airtightness without adequate ventilation can trap moisture.

Use extractor fans, background ventilation and appropriate heating together. Do not block permanent vents serving combustion appliances. Persistent mould, damp patches or a musty smell may need professional diagnosis rather than more heating alone.

Set schedules around occupancy and avoid heating unused rooms more than needed, while protecting the property and occupants from unsafe cold. Thermostatic radiator valves control individual rooms; the main thermostat controls the heating demand for the system.

For a wet central-heating system, balancing radiators and reducing the boiler flow temperature where the home still reaches the required temperature may improve condensing-boiler efficiency. Changes should suit the system and hot-water arrangement.

Hot-water energy can be reduced by repairing dripping taps, using suitable shower flow rates, insulating accessible hot-water pipes and setting cylinder schedules around demand. Do not reduce stored-water temperatures without understanding hygiene controls.

Heating controls and boiler flow temperature →

Power in watts multiplied by time gives energy in watt-hours. Divide by 1,000 for kWh, then multiply by the tariff rate.

Cost = power in kW × hours used × electricity rate

High-power appliances are not always the most expensive over a year; duration and frequency matter. Tumble dryers, electric showers, immersion heaters and portable electric heaters can be significant, while devices left on continuously can create a smaller but persistent baseload.

The appliance calculator starts with example figures for common appliances. Change them to your appliance’s wattage, energy label figure and routine, and use your own unit rate from your bill, rather than relying on a generic list of “worst” appliances. A custom entry covers anything not listed.

Calculate appliance running costs →

Solar panels reduce imports when generation overlaps with use. Batteries move electricity from one time to another but have losses and a finite life. Time-of-use tariffs can reward flexible demand but may charge more during peak periods.

These technologies work best when considered as one system. For example, an EV, heat pump or battery can create flexible demand, but competing devices may all try to use the same cheap period or available connection capacity.

A battery does not need solar panels: it can charge in a cheaper period and power the home later. It only saves money when the price gap is larger than its storage losses and you use enough electricity outside the cheap period.

• Home battery calculator (without solar) →
• Home batteries without solar: guide →
• Smart meters and time-of-use tariffs →

Support differs across England, Scotland, Wales and Northern Ireland. Check the official scheme for the property rather than relying on an installer’s advert.

Warm Homes: Local Grant — England

This can provide funded energy-saving improvements for some low-income households and eligible homes. Current headline criteria include a privately owned or rented home in England with an EPC of D to G and household income usually £36,000 or less, although benefit and postcode routes can also apply. The local authority assesses eligibility and suitable measures.

Energy Company Obligation — Great Britain

ECO4 has been extended to 31 December 2026. It obliges larger suppliers to deliver eligible efficiency and heating measures, but the extension is also intended to complete existing targets and remedy non-compliant work. A scheme end date does not guarantee that a new household application will be accepted.

Great British Insulation Scheme

The Great British Insulation Scheme ended on 31 March 2026. Do not describe it as open or direct users to a new application form. People with an existing case should contact the supplier handling it.

Boiler Upgrade Scheme — England and Wales

Eligible property owners may receive an upfront grant towards a heat pump or, in limited circumstances, biomass. See the heat-pump page for the current values and eligibility link.

Scotland, Wales and Northern Ireland also have nation-specific advice and support. Eligibility, funding and application routes change, so link to the current official service rather than copying an old list of schemes.

• Diagnose the building before selecting a measure.
• Get a written specification, not only a sales summary.
• Compare quotations on the same scope.
• Confirm which surveys, permissions and electrical work are included.
• Check installer certification where the scheme or technology requires it.
• Ask who provides the guarantee and what happens if the installer closes.
• Never sign under pressure or rely on savings that are not explained.
• Keep photographs, specifications, certificates, invoices and commissioning records.

1. Record 12 months of energy use and current tariffs.
2. List comfort, damp, ventilation and repair problems.
3. Check the EPC and building construction.
4. Complete easy controls and draught measures safely.
5. Obtain surveys for suitable fabric improvements.
6. Recalculate heat demand before replacing the heating system.
7. Compare solar, storage and flexible tariffs using the revised demand.
8. Check grants directly with official bodies.
9. Measure consumption and comfort after work is complete.