Why no one can give you a price over the phone
A responsible answer to “how much” requires seeing the building. The soiling has to be identified, the substrate assessed, the access understood. A price given before any of that is a guess dressed as a quote, and it is usually a low one — low enough to win the work, before the variations start arriving. Nothing here should be quoted blind. What follows are the honest ranges the London market works within, and the seven things that move a figure inside them.
The seven factors that set the price
1. Access. This is almost always the largest single line, and it has nothing to do with the cleaning. A ground-floor shopfront reached from a ladder is a different job to a five-storey facade needing a full scaffold, or a mast climber, or a road closure and licensed hoarding. On many London buildings the access provision costs more than the cleaning that happens once you are up there. Any quote that looks unusually low has often quietly assumed the cheapest possible access.
2. The method. The correct method for the stone is not always the cheapest method available. A high-pressure wash is quick and cheap to deliver. Superheated DOFF steam, TORC vortex cleaning, poultices, and nebulous sprays are slower, more skilled, and specified to protect the surface. You are not paying for cleaning in the abstract — you are paying for the right method for your building.
3. The soiling. Light biological growth on a rain-washed elevation lifts easily. A hard sulphate crust bound into sheltered recesses, or decades of layered paint, is slow, careful work that may need two methods in sequence. The blacker and harder the deposit, the more labour it carries.
4. The stone or brick itself. Sound, robust Portland stone tolerates a firm, direct approach. Friable, delaminating, or previously damaged surfaces demand lower settings, more test work, and a slower pass — because the risk of doing harm is higher. Soft London stock brick in particular needs care that a hard modern brick does not.
5. What else the facade needs. Cleaning is rarely the whole job. Once the surface is clean, failed pointing, cracked stone, and open joints become visible — and often it makes no sense to clean without addressing them, because they are why the building is soiling and decaying in the first place. A cleaning-only price and a full facade restoration price are different orders of magnitude, and the gap is repointing and repairs, not cleaning.
6. Listing and consent. On a listed building or in a conservation area, the method must be agreed with the conservation officer, a method statement prepared, a test clean approved, and written records kept. That process is real work and real time. It is also the reason the job is done correctly rather than gambled — but it belongs in the price.
7. London logistics. Parking suspensions, restricted working hours, pavement licences, tight sites, and out-of-hours access on commercial streets all carry cost that has nothing to do with the stone and everything to do with the postcode.
Across the UK market, low-impact specialist cleaning with straightforward access commonly falls somewhere in the region of £15–£30 per square metre. Comprehensive facade restoration — cleaning combined with repointing and selective stone repair — can exceed £250 per square metre. London sits at the upper end for access and logistics. Treat these as the shape of the market, not a quote for your building. Your figure comes from a survey.
Why the cheapest quote is usually the most expensive job
The lowest number on the table is almost always the lowest method: high-pressure water or abrasive blasting, delivered fast, with the cheapest access. On sound, hard stone that might do no lasting harm. On soft limestone or soft London stock brick it does the damage this trade exists to prevent — eroding the surface skin, opening the pores, stripping the weathered patina, and driving water into the masonry.
The bill for that arrives later, and it is bigger. A stone surface that has been blasted re-soils faster because its protective face is gone, so the building looks tired again within a few years. Worse, the damage is often irreversible — you cannot put a tooled surface or a fired brick skin back. The money saved on the quote is spent several times over on the consequence. For the full mechanism, see what pressure washing does to historic stone.
Line them up on scope, not price. Does each name the cleaning method and the reason for it? Does each include a test clean before full works? Is access specified, or assumed? Is repointing and repair included or excluded? Two quotes that differ threefold are usually not the same job — and the number is the last thing to compare, not the first.
What you are actually paying for
With a specialist, the figure covers more than labour and a machine. It covers the survey that identifies the soiling and the substrate. The test clean that proves the method before it is committed to the whole building. The correct method, applied at the correct settings, by someone who has read the stone. The pointing and repairs that make the cleaning worth doing. And, on a listed building, the consent process and the written record that protect both the fabric and you. That is the difference between a building cleaned and a building looked after.
How we quote
We come to the building. The visit is free, across London and the South East, and there is no obligation attached to it. We assess the substrate, identify the soiling, work out the access, and specify the method — then put it in writing within 48 hours. The quote sets out the scope plainly, so you can read it against anyone else’s. Nothing is quoted blind, and nothing is started without a test clean you have seen.
Common questions
How much does stone cleaning cost in London?
There is no single rate. Light, low-impact cleaning with easy access can sit in the region of £15–£30 per square metre, while comprehensive facade restoration that combines cleaning with repointing and stone repairs can exceed £250 per square metre. The largest variable is usually access, not the cleaning itself. A firm figure only comes from a site visit, because the substrate and soiling have to be seen before any method is specified.
Why are stone cleaning quotes so different?
Because they are often quoting different work. A quote based on a photograph and a pressure washer is not comparable to a quote based on a survey, a test clean, and a method matched to the stone. Differences in access provision, method, and whether repointing and repairs are included can move a price several-fold. Compare the scope, not just the number.
Is the cheapest stone cleaning quote the best value?
Rarely. The cheapest quote is usually the cheapest method — high-pressure water or abrasive blasting — which can erode soft stone and soft brick permanently. Repairing that damage, or living with a surface that re-soils faster because its protective skin has gone, costs far more than the difference on the original quote.
Do you charge for a stone cleaning quote?
No. Site visits across London and the South East are free, and we provide a written specification and quote within 48 hours of the visit. Nothing is quoted blind — we assess the building in person before putting a figure to the work.
The most useful thing you can do with a budget is get it assessed against the actual building. We will visit, identify what the facade needs, and give you a written quote you can hold up against any other — at no cost and no obligation.
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