Reducing Home Energy Use: Where the Savings Actually Are

Most household energy advice has a strange blind spot: it concentrates on the smallest uses. Unplug the chargers, switch off standby, turn off the light when you leave the room — all reasonable, none of it addressing where the energy is actually going. In most homes in cooler climates, heating dominates everything else, with hot water a distant second, which means the meaningful savings live in draughts, thermostats and insulation rather than in the socket behind the television.

This guide follows the energy rather than the folklore. It works down from the biggest uses to the smallest, is honest about what costs money versus what is free, and — in keeping with the rest of this site's approach to sustainability — puts behaviour and maintenance ahead of purchases wherever the evidence supports it.

Follow the Energy: The Hierarchy That Matters

The FAQ's central point, as a working order of priorities:

1. Stop heat escaping — draughtproofing first because it is cheap, then insulation where it is worthwhile.
2. Control the heating properly — timing, zoning, and not heating empty rooms.
3. Hot water — usually the second biggest use.
4. The energy-hungry appliances — especially anything that makes heat: dryers, ovens, kettles, hot washes.
5. Everything else — lighting (largely solved by LED) and standby, which are worth doing and will not transform anything.

The reason this ordering matters is that effort spent at the top of the list is worth many times the same effort at the bottom, and most people work from the bottom up.

Draughtproofing: The Cheapest Real Win

The FAQ names it as the best value measure available, and it is worth being specific about where the gaps are:

• Doors: brush strips or seals around the frame, a letterbox brush, a keyhole cover, and a draught excluder at the bottom.
• Windows: self-adhesive foam or rubber strips around opening casements; sealant for gaps between frame and wall.
• Floorboards and skirting: gaps in suspended timber floors let a surprising amount of cold air up — filler, sealant, or a rug over the worst areas.
• Loft hatch: often a straight hole into a cold space; insulate and seal it.
• Unused chimneys: a removable chimney balloon or draught excluder stops a permanent open flue pulling heated air out — with the absolute caveat that this only applies to genuinely unused flues.
• Extension leads, pipes and cables passing through walls: small gaps, easily sealed.

The critical caution from the FAQ: draughtproofing is not the same as sealing a home airtight. Ventilation controls moisture and air quality, and blocking it causes condensation and mould — the exact problem the bathroom and bedroom guides describe. Seal the unintentional gaps; keep trickle vents, extractor fans and the habit of airing rooms.

Heating Controls: Not Heating Empty Space

The FAQ's answer to the thermostat question is worth restating because it reframes the issue: the bigger opportunity is usually not the temperature but what you are heating and when.

• Set the temperature where you are genuinely comfortable — comfort and health come first, and this is explicitly not the place to economise in homes with elderly, unwell or very young occupants.
• Use a timer or programmable thermostat so heating matches occupancy rather than running to a habit.
• Thermostatic radiator valves let you turn down rooms you are not using — the simplest form of zoning, and often the largest single saving after draughtproofing.
• Close doors to unheated and unused rooms; heat follows the path of least resistance.
• Unblock the radiators: furniture and long curtains in front of a radiator absorb and divert heat you have paid for. Reflective panels behind radiators on external walls help in some cases.
• Bleed radiators that are cold at the top — trapped air means you are heating water that never reaches the room.
• Service the system as recommended: an efficient, correctly running boiler or heat pump uses less than a neglected one, and safety checks matter regardless of energy.

Insulation: Where It Is Worth the Money

Insulation costs more than draughtproofing but addresses the same fundamental problem — heat leaving the building — and the sensible order is by cost-effectiveness rather than by visibility:

Building construction varies enormously, and some measures are inappropriate for particular buildings — older, solid-walled and heritage properties especially need advice that accounts for how the building manages moisture. Assessment first, then the work: badly specified insulation can cause damp problems that cost more than the energy it saves.

Hot Water

• Insulate the cylinder and pipes — cheap, effective, and often already half-done badly.
• Set the water temperature sensibly: hot enough for safety and hygiene requirements, not scalding hot and then diluted at every tap.
• Time it, so a cylinder is not being kept hot around the clock when nobody is using it.
• Shorter showers, and showers over baths in most cases — one of the few personal-habit changes that genuinely moves a big number.
• Fix dripping hot taps, which waste both water and the energy used to heat it.
• Efficient shower heads reduce hot water use without the experience feeling noticeably different.

Appliances: The Ones That Make Heat

The FAQ's ranking is the useful one — among appliances, the energy hogs are the ones producing heat:

• Tumble dryers are among the hungriest appliances in a typical home. Line drying — outdoors when weather allows, indoors with ventilation when it does not — is the single biggest appliance saving available, and the laundry guide recommends it for fabric-longevity reasons too.
• Washing cooler saves the energy used heating water, which is most of a wash cycle's consumption; the laundry guide's cool-by-default, warm-when-needed policy is also the energy-efficient one.
• Full loads in washing machines and dishwashers; a modern dishwasher run full generally uses less water and energy than washing the same load by hand under a running tap.
• Kettles: boil only what you need — a small, frequent, easily-fixed waste.
• Ovens: avoid unnecessary preheating, use lids on pans, match pan size to hob ring, and consider smaller appliances (microwave, air fryer, hob) for small quantities rather than heating a large oven cavity.
• Fridges and freezers run constantly, so their efficiency matters: keep coils clear of dust, do not site them next to heat sources, keep seals clean and intact, and defrost when ice builds up.
• When replacing anything, efficiency ratings matter more than they seem, because appliances last years — this is where "buy well once" and energy saving align.

Renting, and What You Can Still Do

Much energy advice assumes you own the building, which leaves renters reading about cavity wall insulation they cannot install. Plenty remains within reach. Draughtproofing is largely reversible and tenant-friendly — self-adhesive strips, draught excluders, chimney balloons, letterbox brushes and heavy curtains all come with you when you leave. Radiator valves, timers and smart plugs are often replaceable and restorable. Every behavioural measure is entirely yours: heating occupied rooms only, closing doors and curtains, line drying, washing cooler and fuller, boiling what you need. Beyond that, it is worth raising genuine problems with the landlord in writing — an uninsulated loft, a broken extractor fan, failed window seals or a boiler overdue a service are maintenance issues as much as energy ones, and in many places minimum efficiency standards and repair obligations apply to rented homes. Knowing which category a problem falls into tells you whether to fix it yourself or to ask.

The Small Stuff, Honestly

Lighting has largely solved itself: LED replacements use a fraction of what older bulbs did, and switching remaining ones is a genuine, done-once win. Standby power and chargers, as the FAQ says, are worth switching off but are a rounding error next to heating — do them because they are effortless, not because they are the answer. The honest risk with small measures is that they provide a satisfying feeling of having addressed the problem while the actual energy continues to leave through the loft and the letterbox.

Cooling and Hot Weather

Energy advice tends to assume heating, but keeping a home cool can be just as demanding where summers are hot, and the principles mirror each other. The cheapest measures are again about the building rather than the machinery: keep the heat out before it gets in by closing curtains, blinds or shutters on sunny sides during the day — external shading is far more effective than internal, because it stops the heat before it passes the glass. Ventilate at night and in the cool of early morning, then close up during the hottest hours, which is the opposite of most people's instinct. Fans use a small fraction of the energy air conditioning does and make a room feel several degrees cooler by moving air over skin, so they are worth exhausting as an option first. Where air conditioning is used, the same control principles apply as with heating: cool the rooms you are in rather than the whole building, set a moderate temperature rather than an extreme one, and make sure doors and windows are closed while it runs. And the same health caveat holds in reverse — in genuine heatwaves, staying cool enough is a safety matter, not an efficiency exercise.

Measure, Then Decide

Guessing where energy goes is unreliable, and there are better options than guessing. A smart meter or energy monitor shows consumption in real time, which quickly identifies the genuinely hungry appliances and habits in your specific home. Comparing bills across seasons shows how much of your use is heating. And where available, a professional home energy assessment gives a prioritised list based on your actual building rather than general advice, which is particularly valuable before spending significant money on insulation. This is the same principle the food-waste guide uses: measure for a short period, find your own pattern, then act on it rather than on averages.

The Classic Mistakes

1. Starting with standby and chargers while heating an empty, draughty house.
2. Sealing a home airtight and creating condensation and mould.
3. Heating rooms nobody uses, with no radiator valves or zoning.
4. Blocking radiators with furniture and curtains.
5. Using a tumble dryer by default when a line would do.
6. Insulating without assessment in buildings that need a different approach.
7. Economising on warmth where health requires it — the one place this whole exercise should not go.

The Bottom Line

Save energy where the energy actually goes. Start with draughtproofing, which is cheap, quick and immediately noticeable — while keeping the deliberate ventilation that stops damp. Then take control of the heating: time it, zone it with radiator valves, close doors to unused rooms, unblock and bleed the radiators, and set a temperature that is genuinely comfortable rather than heroic. Insulate where assessment says it pays, starting with the loft and the hot water cylinder. Line-dry instead of tumble-drying, wash cooler and fuller, and replace appliances with efficiency in mind. Do the small things too, because they are easy — but do them last, and never mistake them for the ones that matter.