Ask what system they are proposing and why it suits your wall, whether they tapped the elevation, where the render will stop relative to the damp-proof course, what happens to the airbricks and the boiler flue, and what their position is on frost and rain. The answers to those five tell you most of what you need to know, because each one is something a contractor can only answer if they actually surveyed the building.
- Any quote given without tapping the walls is an estimate dressed as a price.
- Ask what happens to the airbricks. It is the quickest test of whether someone works properly.
- A contractor who says weather makes no difference is telling you something important.
- Get the system named in writing — manufacturer and product, not just the word silicone.
Before anyone quotes: what should happen at the survey
A rendering quote is only as good as the survey behind it, and surveys vary enormously. Someone who walks the perimeter, looks up, and emails a figure the same afternoon has not established any of the things that determine the price.
What a proper survey involves: tapping the whole elevation to find debonded areas, identifying the wall construction, locating the damp-proof course and checking ground levels against it, testing suction, listing every fixing and airbrick, checking the gutters and roofline above, and looking at the access and where scaffold can stand.
That takes an hour or so on an average house. If it took ten minutes, the number you have been given is a guess, and guesses move once the scaffold is up.
The fifteen questions
About the wall
- Is my wall solid or cavity, and how did you establish that? On a solid wall the system has to be vapour-permeable. Someone who has not checked cannot specify correctly.
- Did you tap the elevations, and how much sounded hollow? This is the single biggest variable in the job. The answer should be a rough area, not a shrug.
- Where is the damp-proof course, and where will the render stop? Render carried down across the DPC bridges it. The right answer involves a bellcast bead above the DPC line.
- What is the suction like, and what primer are you using? If this gets a blank look, preparation is not being thought about.
About the system
- Which system, by manufacturer and product name? "Silicone render" is a category, not a specification. You want it written down.
- Why that system for this wall? There should be a reason connected to the substrate and the exposure, not to what is in the van.
- What is the total thickness, and what does that do at the reveals and sills? Added thickness has consequences, and they should have been thought through.
- Where are the movement joints going? On a large elevation, the answer should not be "we do not usually bother".
About the practicalities
- What happens to the airbricks? The correct answer is that they are sleeved through. Any other answer is a problem.
- Who is moving the boiler flue and the meter boxes? The flue needs a Gas Safe registered engineer. If nobody has mentioned it, it has not been planned.
- What is included on scaffold, and how long will it stand? Scaffold is a real part of the cost and standing time matters if the job overruns.
- What is your position on frost and rain? You want to hear that work stops and dates move. A contractor who will push on regardless is a risk.
About the commercials
- Is the quote fixed, and what would change it? Honest answer: additional removal found once work starts. That should be identified at survey as a possibility and priced as a rate.
- What is the payment schedule? Be wary of large sums up front. Staged payments against progress are normal; most of the money before anything happens is not.
- Can I see your public liability insurance, and recent work? Both reasonable, both easy for a genuine contractor to provide.
Answers that should make you pause
| If you hear this | What it usually means |
|---|---|
| "Render will stop your damp" | Render is a rain screen, not a damp treatment. Different problems |
| "It will insulate the house" | Standard render adds negligible insulation. That is EWI, and it costs more |
| "We can start Monday" in December | Either the forecast has not been checked, or it is not being treated as relevant |
| "No need for scaffold, we will use ladders" | Above ground floor, that is a safety and a quality problem |
| "We do not need to see it, I can price from a photo" | Nothing that determines the price has been established |
| A large discount for deciding today | Pressure selling. A real price does not expire this afternoon |
| "We will render straight over that" (of hollow render) | The new work will debond with the old |
| Cash only, no written quote | No paper trail, no recourse, and questions about insurance |
Comparing quotes that look different
Rendering quotes frequently vary more than people expect, and the cheapest is often cheap for a reason that is invisible until later. The useful approach is to compare scope, not totals.
Line up the quotes against each other and check: is removal of failed render included or extra? Is scaffold in the price? Is making good brickwork included? Are the fixings and the flue accounted for? Is the system the same product? Is there a figure for movement joints and beads, or has the word "beads" not appeared at all?
In our experience a cheaper quote is usually cheaper because it assumes nothing will be found, excludes scaffold, or skips preparation. Those are not savings; they are items that reappear as variations or as a failure in three years.
If one quote is dramatically lower than the others, the most useful thing you can do is take its scope back to the other contractors and ask what they would have excluded to reach that figure.
What should be in the written quote
- The system, named by manufacturer and product, with the build-up and total thickness.
- What preparation is included, and specifically how much render removal is allowed for.
- Scaffold: included or not, and expected standing time.
- Beads and movement joints, with where they fall.
- What happens to airbricks, meter boxes, flue, pipework and any external fittings.
- Where the render starts and stops at the base relative to the damp-proof course.
- The colour and finish, agreed from a sample rather than a brochure.
- A programme with realistic dates and what happens if weather intervenes.
- Payment stages tied to progress.
- What is guaranteed, for how long, and what the manufacturer warranty covers separately.
Costs for context
Knowing roughly where a quote should land makes it easier to spot one that is wrong in either direction. These are the rendering figures published across this site:
| Job | Typical Coventry guide price | Notes |
|---|---|---|
| Rendering | £40–£70 per m² | System & access dependent |
| Three-bed semi | £2,500–£5,000 | Full elevation render |
| Detached house | £9,000–£12,000 | Larger area & scaffolding |
| External wall insulation | £90–£140 per m² | Insulated render system |
A quote dramatically below these is usually excluding something substantial. A quote well above should come with a clear explanation — difficult access, extensive removal, or a wall that needs more than render.
We tap the walls, check the damp-proof course, list the fixings and name the system in writing. Ask us anything on this page.
Frequently asked questions
How many quotes should I get for rendering?
Three is the usual advice and it works, provided you compare scope rather than totals. Two quotes give you no sense of the range; more than four tends to produce confusion rather than clarity. What matters more than the number is that each one is based on an actual survey.
Should a rendering quote be fixed or an estimate?
Fixed, for everything that can be established at survey. The honest exception is additional render removal found once work starts, which cannot be fully known until the wall is opened up — and that should be flagged at survey and priced as a rate per square metre, not left open-ended.
Is a big deposit normal for rendering work?
A modest deposit to cover materials ordered specifically for your job is reasonable. A large proportion of the total before anything happens is not, and it is the pattern most associated with work that never gets finished. Staged payments against visible progress protect both sides.
What guarantees should I expect?
Workmanship guaranteed by the contractor, and a separate manufacturer warranty on the system itself, which is usually longer. Ask for both in writing and check what the manufacturer warranty actually requires — some are conditional on the system being installed by an approved applicator, which is worth knowing before rather than after.
Does my renderer need to be accredited?
There is no legal licensing requirement for rendering in the UK, so accreditation is not mandatory. Some manufacturers operate approved-applicator schemes, and where you want the longest manufacturer warranty that can matter. More practically useful: public liability insurance, recent work you can look at, and a written specification.
What if I am not happy with the finish?
Raise it immediately, in writing, while the scaffold is still up — that is the cheapest moment to correct anything. Agree the colour and texture from a physical sample before work starts rather than from a brochure, because screen and print colours do not match render, and a sample panel on the actual wall is better still.
Ask us the awkward ones
We would rather answer fifteen questions before the job than one after it. Free survey, fixed written quote, system named in writing.