How to Price External Wall Insulation in the UK

Pricing external wall insulation (EWI) jobs wrong is one of the fastest ways to lose money in the trade. Too low and you eat into your margin. Too high and you lose the job to a competitor. This guide breaks down exactly how to price EWI work in the UK, from measuring up to final quote, so you can win profitable jobs consistently.

Understand What You're Pricing First

External wall insulation is not a single product. It's a system. That system includes the insulation board, adhesive, fixings, base coat, reinforcement mesh, primer and a finishing render or cladding layer.

Each element has its own cost. Each job has its own complications. Before you price anything, you need to know:

• What insulation type is specified — EPS, mineral wool or phenolic board
• The thickness required — usually 60mm to 150mm for domestic work
• The wall substrate — brick, block, timber frame or mixed
• The condition of the existing wall — cracks, damp or contamination add cost
• Access requirements — scaffolding or MEWP hire is a significant line item
• Detailing complexity — reveals, soffits, corners and window surrounds take time

Never quote from a phone call or a photo. Visit the site. Measure the walls. Look at the details.

Break Down Your Material Costs

Material costs vary by system and specification, but here are typical ranges for a standard EPS EWI system as of 2024:

• EPS insulation board (100mm): £4–£7 per m²
• Adhesive and base coat: £3–£6 per m²
• Reinforcement mesh: £1–£2 per m²
• Mechanical fixings: £1–£3 per m²
• Primer and finish render: £5–£12 per m²
• Beads, trims and accessories: £2–£5 per m²

Add 10–15% to your material total to cover waste and breakages. Always buy from a merchant where you have a trade account and can control your costs.

If you're using a mineral wool or phenolic board system, your material costs will be higher — often 30–50% more than EPS. Make sure your quote reflects the actual system being installed.

Calculate Your Labour Costs Accurately

Labour is where most EWI quotes go wrong. Tradespeople underestimate how long detailing takes compared to flat field work.

A productive two-person EWI crew can typically install 25–40m² of flat field work per day on a straightforward job. But every window reveal, parapet, door surround and corner detail slows that rate down significantly.

Use these steps to calculate labour:

1. Measure total wall area in m²
2. Identify and count all details — windows, doors, corners, soffits
3. Estimate days for flat work at your realistic daily rate
4. Add days for detailing — roughly one extra day per 10–15 openings on a standard property
5. Multiply total days by your daily labour cost including NI, holiday pay and any subbies

A realistic all-in labour rate for EWI in 2024 runs between £18–£35 per m² depending on complexity and region. London and the South East sit at the top of that range.

Don't Forget Your Prelims and Overheads

Prelims are the costs that don't sit neatly under materials or labour but still come out of your pocket.

For EWI jobs, your prelims typically include:

• Scaffolding: £1,500–£4,000 for a standard semi-detached, depending on duration
• Skip hire or waste disposal
• Plant and equipment hire
• Site protection and sheeting
• Travel and fuel costs

Scaffold hire alone can represent 10–15% of the total job cost. Get a scaffold quote before you price the job, not after.

On top of prelims, you need to recover your business overheads — insurance, vehicle costs, tools, software, marketing and your own time managing the job. Add a percentage to every quote to cover this. For most small to medium contractors, 12–20% overhead recovery is a realistic target.

Set Your Margin and Build Your Price

Once you have your costs, you need to apply a margin. A margin is not the same as a markup — know the difference.

• Markup: the percentage added on top of your costs (e.g. cost £10,000, markup 25% = price £12,500)
• Margin: the percentage of the selling price that is profit (e.g. £2,500 profit on £12,500 = 20% margin)

Most EWI contractors aim for a net margin of 15–25% on a well-run job. If you're below 10%, you're working hard for very little. If you're consistently quoting and losing, check your costs rather than cutting your margin.

Tools like MyQS at myqs.ai let you build EWI quotes quickly using your own rates, so you can produce professional, accurate quotes faster without re-doing the maths on every job.

5 Practical Tips for Pricing EWI Jobs

1. Always visit the site before quoting. Photos and floor plans don't show you wall condition, access issues or hidden details.
2. Get scaffold quotes in early. Scaffold hire is often the biggest variable cost and can make or break your price.
3. Price by m² but quote as a lump sum. Clients don't need to see your rate card. They need a clear price for the job.
4. Specify the system in your quote. State the insulation type, thickness and finish so there's no dispute about what you're installing.
5. Include a programme in your quote. Clients appreciate a start date and duration. It builds confidence and reduces price-comparison shopping.

Frequently Asked Questions

How much does external wall insulation cost per m² in the UK?

Installed EWI typically costs between £80 and £150 per m² for a standard EPS system with render finish. Premium systems using mineral wool or phenolic board can reach £150–£200 per m². Prices vary by region, access difficulty and wall condition.

How do I measure a house for an EWI quote?

Measure the external perimeter of each wall and multiply by the height. Deduct windows and doors. Add back in the reveals, as these need to be insulated and finished too. Use a laser measure on site for accuracy. Always double-check your figures before pricing.

Can I make a good profit from EWI work?

Yes, EWI can be highly profitable when priced correctly. The key is accurate measurement, realistic labour rates, full prelim recovery and a proper margin. Contractors who price from experience rather than spreadsheets often undercharge on complex detailing. Build a pricing system you trust and stick to it.

Conclusion

Pricing external wall insulation well comes down to one thing: knowing your costs before you name your price. Measure accurately, cost every element, recover your overheads and apply a realistic margin.

If you want to build and send professional EWI quotes faster, visit myqs.ai to see how MyQS helps UK tradespeople price jobs with confidence.