Thermal curtains reduce heat loss through windows by up to 25%
A single-glazed window loses around 10 times more heat than a typical insulated wall, and even double glazing loses heat at night. According to the Energy Saving Trust, fitting thermal curtains can cut heat loss through windows by up to 25% (Energy Saving Trust, 2026). This reduction translates into lower heating demand, especially during winter evenings when curtains are closed. The effect is most pronounced on single glazing, but thermal curtains also improve the performance of older double glazing.
Thermal curtains save £25-£50 per year on heating for a typical 3-bed semi with gas central heating, per the Energy Saving Trust. Savings are highest on single glazing and lower on modern double glazing.
- Cut heat loss through windows by up to 25% (Energy Saving Trust).
- Save £25-£50 per year in a typical 3-bed semi with gas heating.
- Ready-made curtains cost £30-£80 per window; made-to-measure £80-£150.
- Full set for 8-10 windows costs £240-£800, DIY-friendly to install.
- Payback in 5-16 years for single glazing; longer for double glazing.
- Thermal curtains reduce heat loss through windows by up to 25%
- The average annual saving from thermal curtains in a UK home
- Thermal curtains cost £30 to £150 per window – the total for a typical home
- Quick numbers – thermal curtains savings and payback
- The payback period for thermal curtains is 10–30 years depending on your windows
- Thermal curtains savings are real but modest – they work best as part of a draught-proofing package
- How to verify a thermal curtain installer – MCS is not relevant, but look for TrustMark or a curtain specialist
- The direct answer to "How much do thermal curtains save?" – £25–£50 per year for a typical UK home
The average annual saving from thermal curtains in a UK home
For a typical three-bedroom, semi-detached house with gas central heating, the Energy Saving Trust estimates savings of £25 to £50 per year from thermal curtains (Energy Saving Trust, 2026). The exact saving depends on window area, glazing type, and how consistently curtains are drawn at dusk. Homes with single glazing will see savings at the higher end of this range; those with modern double glazing will see lower savings. These figures assume curtains are closed from late afternoon until the next morning throughout the heating season, which runs from October to March.
Thermal curtains cost £30 to £150 per window – the total for a typical home
Ready-made thermal curtains range from £30 to £80 per window; made-to-measure options cost £80 to £150 per window. A typical three-bedroom house has 8 to 10 windows, so a full set of ready-made thermal curtains costs £240 to £800. Installation is DIY-friendly using a curtain pole and rings, but hiring a handyperson adds £20 to £50 per window (Checkatrade, 2026). The upfront cost is significantly lower than secondary glazing, which runs £200 to £500 per window, or replacement windows at £500 to £1,500 per window.
Quick numbers – thermal curtains savings and payback
The table below compares savings and payback across different glazing types. All figures assume a typical three-bedroom semi-detached house with gas central heating.
| Glazing type | Annual saving (per window) | Annual saving (whole house) | Cost per window | Payback period (whole house) | Heat loss reduction |
|---|---|---|---|---|---|
| Single glazing | £5–£6 | £40–£50 | £50 | 10–12 years | 25% |
| Old double glazing (pre-2002) | £3–£4 | £25–£35 | £50 | 14–20 years | 10–15% |
| Modern double glazing (post-2002) | £2–£3 | £16–£25 | £50 | 20–30 years | 5–10% |
| Single glazing with thermal lining only | £4–£5 | £30–£40 | £15 (lining fabric) | 5–8 years | 20% |
Sources: Energy Saving Trust savings tables (Energy Saving Trust, 2026); typical retail prices from major UK retailers.
The payback period for thermal curtains is 10–30 years depending on your windows
For a typical home with single glazing, the payback period is 10 to 12 years – the curtains pay for themselves in saved heating bills. For homes with modern double glazing installed after 2002, the payback extends to 20 to 30 years, making thermal curtains a comfort investment rather than a pure money-saver. If you already have curtains and only need a thermal lining fabric, which costs £10 to £20 per metre, payback drops to 5 to 8 years. The savings are lower than loft insulation, which has a payback of 2 to 3 years, but comparable to draught-proofing windows, which pays back in 5 to 10 years (Energy Saving Trust, 2026).
Thermal curtains savings are real but modest – they work best as part of a draught-proofing package
Thermal curtains alone will not transform your energy bills; they are most effective when combined with other low-cost measures like draught-proofing strips and door seals. The Energy Saving Trust states that full draught-proofing, including curtains, strips, and chimney draught excluders, saves £60 to £100 per year for a typical home (Energy Saving Trust, 2026). Thermal curtains also provide side benefits: they block cold draughts from window frames, reduce condensation, and improve bedroom darkness for sleep. For the best effect, curtains should be floor-length, have a separate thermal lining with an aluminium foil-backed layer, and be fitted with a pelmet or close to the ceiling to trap a layer of insulating air (DESNZ, 2026). How to draught-proof your home effectively
How to verify a thermal curtain installer – MCS is not relevant, but look for TrustMark or a curtain specialist
Thermal curtains do not require MCS certification, which is for renewable technologies like solar panels or heat pumps. For made-to-measure curtains, check the supplier is registered with TrustMark, the government-endorsed quality scheme for home improvements (TrustMark, 2026). If you are buying ready-made curtains, no installer certification is needed – you can fit them yourself. For custom curtain tracks or motorised systems, ensure the fitter is a member of the British Blind and Shutter Association (BBSA) or holds relevant public liability insurance. How to find a reliable home improvement tradesperson
£25–£50 per year for a typical UK home
For a three-bedroom semi-detached house with gas central heating, the Energy Saving Trust estimates annual savings of £25 to £50 (Energy Saving Trust, 2026). The savings come from reduced heat loss through windows at night, not from daytime solar gain. If your home has single glazing, expect savings at the top of this range; if you have modern double glazing, expect savings at the bottom. These figures assume you close curtains every evening and open them during the day to let in sunlight.
Frequently Asked Questions
The Energy Saving Trust estimates £25 to £50 per year for a typical three-bedroom semi-detached house with gas central heating. Savings are higher for single-glazed windows and lower for modern double glazing.
Yes, thermal curtains are worth it for single glazing or older double glazing, saving £25-£50 per year according to the Energy Saving Trust. They also reduce draughts and improve comfort at a much lower cost than secondary glazing or new windows.
Ready-made thermal curtains cost £30 to £80 per window; made-to-measure options cost £80 to £150 per window. A typical three-bedroom house with 8-10 windows will cost £240 to £800 for a full set.
Yes, thermal curtains reduce heat loss through windows by up to 25%, according to the Energy Saving Trust. This is most effective on single glazing but also improves older double glazing performance.
Payback period depends on window type and savings: for single glazing, 5-16 years; for double glazing, 16-32 years. The Energy Saving Trust figures show lower savings for modern double glazing, extending payback.
