How much does it cost to insulate a loft?

Loft insulation is priced by loft area. Enter your loft footprint below — it's one of the cheapest ways to lift an EPC.

Loft insulation cost calculatorLive estimate

Mineral wool to 270mm. Boarded loft or top-up over existing costs a little more.

Estimated cost
£945
range £540£1,350
£21/m²
With 10–15% contingency£1,063

Indicative estimate — confirm with quotes.

What loft insulation involves

  1. 1
    Measure the loft

    Insulation is priced per m² of loft floor area — usually a bit less than the ground-floor footprint.

  2. 2
    Depth to 270mm

    Current guidance is around 270mm of mineral wool; topping up thin existing insulation is cheaper than a full lay.

  3. 3
    Ventilation and boarding

    Keep eaves ventilation clear; raised boarding to retain storage adds cost but avoids compressing the insulation.

Loft insulation is the classic quick EPC win — cheap, fast and low-disruption. On a refurbishment aimed at MEES compliance it's usually the first improvement to price in.

Loft insulation costs (indicative)

PropertyLoft areaIndicative cost
Flat / small~25 m²£300 – £650
3-bed house~45 m²£550 – £1,200
Large / detached~70 m²£850 – £1,900
Per m² (270mm)£12 – £30/m²

Roll insulation to 270mm. Insulating a boarded loft or a room-in-roof costs more.

Frequently asked questions

How much does loft insulation cost?+

Loft insulation typically costs £12–£30 per m², so a 3-bed house (~45 m² loft) is roughly £550–£1,200. It's one of the cheapest ways to improve an EPC.

Does loft insulation improve the EPC?+

Yes — increasing loft insulation to the recommended depth is a low-cost, high-impact EPC improvement, which matters for lettings under minimum energy standards.

Related tools & guides

Want to know how these figures are calculated? See our cost methodology.

Indicative estimates — not a quotation

Cost figures shown are indicative estimates, not quotations. You are responsible for verifying all costs (obtain contractor quotes) and any figures submitted to a lender. ScopeWise is a documentation tool, not financial, tax, structural or planning advice. HMO compliance prompts are guidance only — confirm requirements with your local council, as standards and licensing vary by authority.