Key takeaways
- Everything here costs under £600 and most pays back inside two winters
- The "skip if" column matters: half these measures are useless in the wrong house
- A typical untouched 3-bed can cut £400–£600 a year for under £500 spent
- Renters can do almost all of it without permission
- ECO4 makes the installer-done items free for qualifying households
The short answer
A typical untouched 3-bed can cut £400–£600 a year for under £500 spent, and nothing on this page costs more than £600. The fastest items are free or nearly so: the thermostat down 1°C (about £56 a year), a jacket on a bare hot water cylinder (£18, about £70), a chimney balloon in an unused flue (£25, about £65).
The catch is that half these measures do nothing in the wrong house, which is what the skip-if column is for. ECO4 makes the installer-fitted items free for qualifying households.
The whole list, ranked by payback
Everything under £600, ranked by how fast it returns the money in a typical gas-heated 3-bed. Electric heating? Multiply the savings by roughly three and the ranking barely changes.
| # | Measure | Cost | Annual saving | Payback | Skip if... |
|---|---|---|---|---|---|
| 1 | Thermostat down 1°C | £0 | ~£56 | Instant | Already at 18–19°C |
| 2 | Cylinder jacket (bare tank) | £18 | ~£70 | 3 months | Cylinder is factory foam-coated |
| 3 | Chimney balloon | £25 | ~£65 | 5 months | No open unused chimney |
| 4 | Pipe lagging (hot pipes) | £10 | ~£15 | 8 months | Pipes already lagged |
| 5 | Draught-proofing (whole house) | £100–£180 | ~£90–£130 | 1–2 years | Post-2013 new build |
| 6 | Loft top-up (100→270mm) | £150–£400 DIY | ~£100–£200 | 1–3 years | Already at 270mm |
| 7 | TRVs on every radiator | £80–£200 | ~£60–£120 | 1.5–3 years | Rooms all used equally, all day |
| 8 | Radiator reflectors | £25 | ~£10–£50 | 0.5–3 years | Walls are insulated |
| 9 | LED any remaining halogens | £3/bulb | ~£8/bulb | 5 months | Already all-LED (most homes) |
| 10 | Smart thermostat | £100–£250 | ~£80–£160 | 1.5–3 years | You already run tight schedules |
| 11 | Kill standby loads (smart plugs) | £20–£40 | ~£30–£60 | ~1 year | Modern kit only, low standby |
| 12 | Secondary glazing film (single glazing) | £15/window | ~£40–£80 | 1–2 years | Already double glazed |
The "skip if" column is the point of this page. Half of these measures are brilliant in one house and useless in the next door one. The links go to honest per-measure breakdowns and calculators.
Where the £600 actually goes, worked example
A draughty 1970s 3-bed on gas, nothing done yet, £600 budget:
- Thermostat 21→20°C: £0, saves ~£56/yr
- Cylinder jacket + pipe lag: £28, saves ~£85/yr
- Chimney balloon: £25, saves ~£65/yr
- Whole-house draught-proofing kit: £130, saves ~£110/yr
- Loft top-up, DIY, two rolls: £180, saves ~£150/yr
- Radiator reflectors (4 external-wall rads): £25, saves ~£30/yr
Total: about £390 spent, roughly £500 a year saved, everything paid back by next spring. That return beats any solar panel, heat pump or window quote you will ever receive, which is why this list comes first.
What this list deliberately leaves out
- Cavity wall insulation (£300–£600): it belongs at the top when suitable, but it is installer-done and construction-dependent, check your house type guide first (1930s semi, 1960s semi, ex-council).
- Anything over £600: solar, batteries, heat pumps and glazing have their own pages and their own maths.
- Gimmicks: "eco" plug devices that claim to clean electricity, and magnetic boiler gadgets. No credible trial shows meaningful savings from either. Radiator booster fans are a slightly different case: the physics is real and they cost under £2 a year to run, but the bill saving in a boiler-heated house is small enough that we have kept them off this list.
- Appliances: the running cost of what you plug in is a separate question from the fabric of the house. We have worked the numbers on heated airers, air fryers, dehumidifiers and the rest at current cap rates.
Renting? Most of this list still works
Nothing above needs a landlord's permission except the loft top-up and arguably the TRVs. Draught-proofing, reflector panels, the chimney balloon, glazing film and every behaviour change travel with you when you move. Flat dwellers: the flat and leasehold guide ranks these for smaller spaces. If you are drying laundry indoors because there is no outside space, a covered heated airer costs about 31p a load against 91p for a condenser tumble dryer, and needs no landlord's permission either.
Frequently asked questions
What is the single best cheap energy-saving measure?
If the thermostat is at 21°C or higher, turning it down one degree: free, instant, ~£56 a year in a typical home. If it is already sensible, the cylinder jacket (if you have a bare tank) or the chimney balloon (if you have an open flue) are the fastest paybacks money can buy.
How much can cheap measures save in total?
A previously untouched house can realistically cut £400 to £600 a year for under £500 spent. A house where the basics are done might only find £100. The "skip if" column above is the difference.
Are any of these grant-funded?
ECO4 covers the installer-done versions (loft, cavity, draught-proofing) for qualifying households, at which point they are free and this whole page becomes your shopping list for the gaps. Check ECO4 first if anyone in the house receives benefits.
Do cheap measures affect a heat pump later?
They help. Every kWh of heat loss you remove shrinks the heat pump you will eventually need, and draught-proofing plus loft insulation are exactly what an MCS surveyor wants to see done before sizing one.
Sources
Energy Saving Trust typical savings data, Ofgem Q3 2026 price cap. Figures are indicative for a typical 3-bed gas-heated home in England; electric heating multiplies fuel-cost savings by about 3.5.