CalculatorFree tool
External wall insulation cost per m², built up properly
Start from the benchmark — published wages, a real gang, the costs on top of wages most people forget — then move anything you disagree with. The whole sum stays on the page.
The working
- 1 × tradesperson at £16.40
- £16.40
- 1 × labourer at £13.18
- £13.18
- Gang wage, per hour
- £29.58
- + 35% on top of wages
- £39.93
- × 8 hours on the tools
- £319.46 a day
- Boards with a render finishfixed, meshed and finished in silicone£319.46 ÷ 10 m² × 1.20 = £38.34/m²
Benchmark
£38.34/m² labour
CIJC rates · tradesperson £16.40/hr + labourer £13.18/hr · gang of 1+1 · 35% on top · overheads and profit 20%
Materials, scaffold and supervision are not included in this rate.
What’s in this?
- Employer's National Insurance — 15% above £5,000 a year
- Holiday pay — 12.07%
- Pension, auto-enrolment minimum — 3%
- CITB levy — 0.35% of payroll
- Sick pay, training and employer's liability insurance — the remainder
- At 0% this is a CIS subcontractor's labour price — National Insurance, holiday and pension are then theirs to carry, not the job's.
The location range is authored, not measured — our tender data says what was bought where, not what labour costs there.
Price a whole job with this ratePut in the job size and your lump sums — scaffold, plant, skip — and get the job total.
The minimum starts at a day of the gang, priced — £383.36 — because travel, unloading and setting up make a day the honest floor. Type your own, or 0 for none.
Put a job size in and the total appears here.
External wall insulation is a system, not a material
EWI is installed as a specified system — boards, fixings, adhesive, mesh, basecoat and finish, all from one manufacturer and tested together. That matters commercially because the specification is generally decided before pricing, and it is what the warranty depends on. Mixing components across systems is how a guarantee is lost.
So the useful question is not “what does EWI cost per square metre” but “what does the system I have been asked to install take, on this building.” The chain in this calculator prices that once you know it.
Why 10 m² a day, and where it goes
The benchmark assumes a straightforward elevation: fix the boards, mechanically fix them, mesh and basecoat, then the finish. It is slow relative to rendering because it is more layers, and because almost none of the day is on flat wall.
- Detailing. Reveals, sills, verges, the base track and every junction where the insulation stops is where the time and the risk both sit. A wall is fast; a window is not.
- Building services. Everything fixed to the outside of a house — soil pipes, gutters, meter boxes, outside taps, satellite dishes — comes off, gets extended, and goes back.
- Making good. The wall behind has to be sound and dry before anything is fixed to it. What the survey found determines how much of that is in the price.
- Access. Full scaffold on every elevation, for the duration, as a lump sum rather than part of the rate.
Every EWI job is different, and the survey is the price
More than any other trade on this site, EWI resists a published rate. A simple detached box with clean elevations and a straightforward system is a completely different job from a terraced property with bay windows, decorative brickwork, shared boundaries and neighbours’ services crossing the wall.
Whoever surveyed the building knows which it is. This calculator turns that judgement into a defensible number by holding everything else steady — the gang, the published wages, the costs on top, your overheads — so the only thing you are changing is the output you already know.
What sits outside this figure
The system materials, the scaffold, the making good, and any certification, warranty registration or compliance work the scheme requires. On funded or grant-backed work in particular there is administration that has nothing to do with the wall and everything to do with getting paid.
What this card gives you is a labour figure built from published wage rates with nothing forgotten — a starting point for the parts of the job that are labour, not a quote for the whole scheme.
Questions people ask
How long does external wall insulation take per square metre?
Around 10 m² a day for a two-person team fixing boards, meshing, basecoating and finishing a straightforward elevation. Detailing around windows, reveals and sills is where most of the time actually goes, so a wall with many openings runs considerably slower than an open gable.
Why is external wall insulation priced as a system?
Because the boards, fixings, adhesive, mesh, basecoat and finish are tested and warranted together as one manufacturer's system. The specification is normally decided before pricing, and substituting components across systems generally invalidates the guarantee.
Does external wall insulation include scaffold?
Not in this rate. EWI needs full scaffold on every elevation for the duration of the work, which is priced by lift, elevation and hire period as a lump sum rather than per square metre of wall.
What has to happen before EWI can be installed?
The wall behind must be sound and dry, and everything fixed to the outside of the building — soil pipes, gutters, meter boxes, outside taps — has to be removed, extended and refitted over the new thickness. How much of that is in the price depends entirely on what the survey found.
Why do EWI quotes vary so much between properties?
Because the building's shape drives the labour more than its area does. A simple detached property with clean elevations is a different job from a terrace with bay windows, decorative brickwork, shared boundaries and neighbouring services crossing the wall. It is a trade that has to be priced from a survey.
Where these figures come from
The wages are the national minimums agreed between employers and unions, republished each July. The costs on top of them are the statutory ones every employer actually pays. The outputs — how much a gang gets through in a day — are blended from published estimating guidance, and they are the part worth arguing with, which is why every one is a control you can move.
Other trades
- Bricklaying£35.68/m²
- Blockwork£23.84/m²
- Plastering£8.50/m²
- Rendering£38.34/m²
- Floor screed£2.83/m²
- Concreting£7.92/m²
- Tiling£17.71/m²
- Roofing£32.80/m²
- Block paving£25.56/m²
- Tarmac driveways£15.34/m²
- Resin driveways£16.61/m²
- Painting£14.17/m²
- Stud walls£17.71/m²
- Patios£31.95/m²
- Repointing£26.57/m²
- Plasterboarding£12.39/m²
- Decking£31.88/m²
- Fencing£25.56/m²
- Turfing£3.42/m²
- Coving£7.08/m²
- Loft insulation£4.27/m²
- Soft strip£8.54/m²
- Hand excavation£85.41/m²
- Shuttering£8.50/m²
- Mesh and rebar£2.56/m²
Pricing a job like these?
HubTrack is where small construction firms keep their compliance documents, their jobs and their evidence trail in one place — method statements and risk assessments prepared for you to check and sign off, and a record of who signed what and when. The same engine that reads the contract documents behind this page reads yours inside HubTrack.