A simple paper test could help homeowners spot heat leaks and cut heating bills this winter.
Placing a strip of paper into an opening window frame before closing and locking it reveals whether seals have degraded.
If the paper slides out with little resistance, the seal is failing to make firm contact.
Professional draught-proofing for a standard window costs around £50, though adjustments or new seals may suffice.
Kaitlin Wood, Senior Category Manager at Travis Perkins, said: "Homeowners often focus on their boiler or thermostat when preparing for winter, but heat can also escape through small gaps and poorly insulated areas around the property."
Rob Haddock, Senior Group Commercial Category Manager at Travis Perkins, added: "The paper check can help homeowners identify where a seal may be weaker, but it does not reveal why the gap has developed."
Avoiding loft insulation compression
An uninsulated roof accounts for around a quarter of a home's heat loss, according to the Energy Saving Trust.
The organisation recommends maintaining 270mm of mineral wool loft insulation, with topping up from 120mm typically costing £750 in a semi-detached house.
Stacking storage boxes directly onto insulation compresses the fibres and slashes thermal performance.
Mr Haddock said: "Adding more insulation will not necessarily solve the problem if it is then compressed beneath boxes or loft boards."
Diagnosing cold radiators
Radiators must also be inspected once central heating systems fire up.
A radiator cold at the top usually points to trapped air, whereas cold spots at the base indicate internal debris.
Uneven warm-up times between rooms can signal a wider system balance issue rather than a simple bleeding job.
Ms Wood said: "Uneven heat is a symptom rather than a full diagnosis. Turning up the thermostat could make other rooms unnecessarily warm without resolving the original problem."
Insulating tanks and stopping draughts
Exposed hot-water pipework in unheated garages and lofts should be fitted with foam lagging to prevent freezing and thermal waste.
Fitting an 80mm British Standard cylinder jacket can save around £40 each year in Great Britain.
Households can also seal gaps along skirting boards and between floorboards with flexible filler, as timber naturally moves over time.
Critical ventilation such as air bricks, extractor fans and window trickle vents must never be blocked, ensuring safe indoor air quality.
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