Free External Wall Insulation Quote
External Wall Insulation Cost Calculator
Calculate your external wall insulation cost per m² in seconds with our free online tool.
Receive your personalised PDF estimate by email after you submit — for EPS, Rock Wool or Kingspan, plus energy-saving tips and grant guidance. No obligation, ever.
Cost Calculator
Instant External Wall Insulation Cost Calculator
Get your external wall insulation estimate by email in under one minute after you submit.
Enter your wall sizes, choose your insulation type, then click “Submit Form“.
Why check your EWI cost online?
- Save time – skip back‑and‑forth calls and know your budget today.
- Transparent pricing – compare EPS, Rock Wool or Kingspan at a glance.
- Energy‑saving insight – preview potential EPC gains before you commit.
- Zero obligation – tweak wall sizes & extras until you’re happy, then click Submit Form.
Try the calculator now
Enter your wall lengths and height, pick an insulation type and click “Submit Form”
We’ll crunch the numbers and email a detailed PDF you can keep.
How we calculate your external wall insulation cost per m²
- Wall area – total length × height (many UK external wall insulation calculators ignore height – we don’t).
- Material rate – choose:
• EPS £115/m²
• Rock Wool £140/m²
• Kingspan £130/m² - Site extras – soil / waste / down pipes, outdoor sockets, lights and cameras.
- Soffit insulation (optional) – £80 / linear metre if you tick the box.
Average external wall insulation prices 2025
Bungalow ≈ 80 m²
- EPS ≈ £9,200
- Rock Wool ≈ £11,200
- Kingspan ≈ £10,400
End‑Terrace ≈ 100 m²
- EPS ≈ £11,500
- Rock Wool ≈ £14,000
- Kingspan ≈ £13,000
Semi‑Detached ≈ 120 m²
- EPS ≈ £13,800
- Rock Wool ≈ £16,800
- Kingspan ≈ £15,600
Detached 2‑storey ≈ 170 m²
- EPS ≈ £19,550
- Rock Wool ≈ £23,800
- Kingspan ≈ £22,100
Prices include labour and materials but exclude scaffolding and waste removal – those are itemised after our free site survey.
Can external wall insulation pay for itself?
The Energy Saving Trust says un‑insulated solid walls can lose up to 45 % of a home’s heat.
Upgrading costs £6,000 – £15,000 on average and typically:
- cuts heating bills by £400 – £900 per year*
- often moves homes up one or two EPC bands*
*Source: Energy Saving Trust 2024
Recent EWI projects
Ready for a firm quote?
Finish the calculator and click “Submit Form”.
You’ll instantly receive:
- Your personalised PDF estimate by email
- Easy link to book a free site survey within 48 h
Prefer a chat? Call 07594 373 464 or visit our contact page.
External Wall Insulation FAQs
How accurate is the online calculator?
The figure is usually within ±10 % of the final price. A free site inspection confirms scaffolding, waste and any access factors.
What is the cost of external wall insulation per m²?
From £110/m² for EPS, £135/m² for Rock Wool and £125/m² for Kingspan in 2025. Use the calculator for a personalised figure.
Want independent advice first?
Read the Energy Saving Trust’s solid‑wall guide.
Area We Cover
Office Location
Over 21 Years of Experience
Why Choose EWI Specialists?
With 21+ years’ experience, our fully insured installers deliver external wall insulation and rendering that lasts – protecting brickwork, cutting heat loss and refreshing your façade. Tidy, on-time workmanship, clear pricing, and 4.9★ Google-rated service.