Our independent scoring system rates every UK insulation type across 5 factors — no manufacturer pays to rank higher.
Key fact: A significant amount of heat — often around a quarter — can escape through the roof if your insulation isn’t up to modern standards. Heat naturally rises, so without effective insulation in place, it escapes through your roof — increasing energy bills and reducing comfort in your home.
Every type scored across cost, efficiency, lifespan, risk, and installation complexity
Answer 4 quick questions. Get a personalised recommendation with savings estimate and a free local installer quote.
Check My Home in 30 Seconds →| Type | Score | Typical Cost | Annual Saving | Payback | Mortgage Risk |
|---|---|---|---|---|---|
| Foil Insulation Top Pick | 8.5/10 | £200–£600 | £150–£250 | 1–3 yrs | ✓ None |
| Fibreglass / Mineral Wool | 7.5/10 | £300–£500 | £100–£200 | 2–4 yrs | ✓ None |
| Underfloor Insulation | 7.2/10 | £400–£800 | £50–£100 | 5–8 yrs | ✓ None |
| External Wall Insulation | 7.0/10 | £6k–£15k | £200–£400 | 20–30 yrs | ✓ None |
| Internal Wall Insulation | 6.5/10 | £2k–£8k | £150–£300 | 10–20 yrs | ✓ None |
| Cavity Wall Insulation | 6.0/10 | £400–£800 | £150–£250 | 2–5 yrs | ✓ None |
| Spray Foam ⚠ | 4.0/10 | £1k–£2.5k | £100–£200 | 8–15 yrs | ✗ Major risk |
Spray foam warning: Multiple major UK mortgage lenders decline applications on homes with spray foam on roof timbers. See our full spray foam risks guide.
Free comparison. Personalised recommendation. One vetted local installer. No pressure.
Check My Home Now →