Quick Answer
Material costs are forecast to keep rising through 2026. BCIS puts all-work materials up 3.2% year-on-year to April 2026; the Builders Merchants Federation reports an average 5.4% rise in Q1 prices; and specific categories like structural steel, aggregates and imported timber are already running at 8 to 13% year-on-year. If you quote a £5,000 job at a 20% gross margin and materials rise 9.5% between quote and order, your profit drops by almost a fifth. Protect your margin with shorter quote validity windows, a written price-adjustment clause, and a small buffer baked into every materials line. Don't wait until a bad quarter to fix it.
Table of Contents
- The 2026 material cost picture
- What's actually rising, and by how much
- The margin maths nobody shows you
- Step 1: Shorten your quote validity
- Step 2: Write a price-adjustment clause
- Step 3: Build a margin buffer into every quote
- Step 4: Talk to your suppliers earlier
- Step 5: Talk to your clients without losing the job
- What tradespeople are saying
- Recommended videos
- Frequently asked questions
- My verdict
The 2026 material cost picture
Material prices have been the quiet story of the last two years. Headlines focus on labour shortages and the housing market. The numbers your merchant gives you, week to week, are where margin actually disappears.
Here is the picture for 2026, drawn from the bodies that track it. BCIS, which publishes the official UK construction materials index, has all-work materials running at 3.2% year-on-year to April 2026. The Builders Merchants Federation's Winter Forecast puts Q1 2026 average prices 5.4% above Q1 2025. Arcadis, in its Spring 2026 UK Market Outlook, projects buildings inflation of 5 to 6% from 2026 onwards. JLL's H1 2026 Construction Perspective settles on 3.5% for the year.
That is the average. The category-level numbers are what hurts.
Industry forecasts for individual material categories are running between 6 and 13% for 2026, with the upper end touching the 9.5% trade-press shorthand for vulnerable areas like steel, copper-heavy electrical, and imported timber. That is what you are quoting against. And so the question is no longer whether prices will move. It is how much movement your quote can absorb before the job stops being profitable.
What's actually rising, and by how much
Not every material is rising at the same rate. If you understand which lines are moving fastest, you can quote around them.
The GOV.UK Building Materials commentary for March 2026 lists the biggest year-on-year movers. Imported sawn and planed wood is up 7.6%. Gravel, sand and aggregates are up 7.3%. Plastic doors and windows are up 5.6%. Concrete reinforcing bars are actually down 7.2%, and imported plywood is down 6.7%. So timber is not a single story, and steel is not a single story either.
The Southern Construction Framework, which collected Q1 2026 data from over 150 subcontractors, reported steelwork up 13.3% and groundworks up 6.3%. They forecast a further 8% across-the-board rise by Q1 2027, with steelwork pushing 11.2% and brickwork pushing 9%. Steel prices are expected to lift another £300 a tonne by Q3 2026 ahead of July import tariffs.
For an electrician, the cable line is the obvious pain point. Copper prices rose roughly 30% over 2025 and have continued upward into 2026, driven by data centre and renewables demand. Two-and-a-half mil twin-and-earth that was £39 plus VAT for a 100m drum in some merchants has been seen at £61 plus VAT in others, a 56% gap that lives between order dates rather than between merchants.
For a plumber, the copper story shows up in pipe and fittings. Homeowners requesting copper systems on boiler installs are now being quoted £1,000 more than they were 18 months ago for the same job spec, almost entirely down to the metal.
For a general builder, timber and aggregates are the volatile lines. A roof carcass quoted in January 2026 and ordered in May 2026 is materially different in cost.
The takeaway is not "everything is up." It is "know which lines are moving on your quote, and price them differently." When it comes to plasterboard, sanitaryware, or fixings, prices have been broadly flat. When it comes to structural steel, cable, copper pipe, or imported timber, weekly is the new monthly.
The margin maths nobody shows you
This is the bit that decides whether your business survives a bad quarter. Most trades businesses run on a 15 to 20% gross margin. RapidQS's 2026 benchmark for a healthy small builder is 15 to 20% gross, 5 to 8% net, with overheads at 8 to 12% of turnover. Anything below that and a single material spike puts the job into the red.
Here is the maths on a £5,000 job, modelled at a 20% gross margin.
| Scenario | Quote price | Materials cost | Labour + overhead | Gross profit | Gross margin |
|---|---|---|---|---|---|
| Quote date | £5,000 | £2,000 | £2,000 | £1,000 | 20.0% |
| Materials rise 5% before order | £5,000 | £2,100 | £2,000 | £900 | 18.0% |
| Materials rise 9.5% before order | £5,000 | £2,190 | £2,000 | £810 | 16.2% |
| Materials rise 13% before order | £5,000 | £2,260 | £2,000 | £740 | 14.8% |
A 9.5% material rise on a job where materials are 40% of the price wipes out roughly a fifth of your gross profit. On the same job with materials at 60% of the price (typical for an electrical rewire or a heating install), a 9.5% rise drops gross profit by almost a third. That is the difference between a tidy quarter and a tight one.
The point is not to memorise the maths. The point is to internalise the relationship: small percentage rises in materials translate into much larger percentage drops in profit, because your margin is the cushion that absorbs the rise. The thinner your margin, the louder the impact. Aaron McLeish covers the underlying mechanics in detail in his trades pricing calculator, and if you have not done that calculation in twelve months, the rest of this article will not save you.
Step 1: Shorten your quote validity
This is the simplest change and the one most businesses still have not made. A quote validity of 30 days has become the new UK norm. Cost Estimator's 2026 builder guide explicitly recommends 30 days, down from the 60 or 90 days that used to be standard.
For volatile categories, even 30 days is generous. A £15,000 quote with £4,000 of structural steel, written in January 2026 and held open until April 2026, is exposed to the SCF's 8% Q1-to-Q1 forecast plus the £300-a-tonne steel tariff jump expected in Q3. That is a £320 hit on one line item from a delay you may not even cause.
The wording matters. "This quote is valid for 30 days from the date above" is fine. "After this date, materials will be re-priced at the merchant's then-current rate and the quote total adjusted accordingly" is better. The latter shifts the conversation from "the price went up" to "the conditions changed, here is the revised number."
Step 2: Write a price-adjustment clause
If you only ever read one paragraph of this article, read this one. A written price-adjustment clause is the single highest-impact tool you have. It does not need a solicitor. It needs three sentences in plain English, in your written quote and in your contract, that the client signs.
JCT, which governs most formal UK construction contracts, offers three fluctuation options. Option A covers tax and statutory changes only and JCT itself notes it "will not assist in relation to material cost increases." Option B handles named labour and material fluctuations against a baseline date. Option C uses formulaic indexation against published RICS indices. NEC4 has the equivalent Option X1.
For a domestic plumber, electrician or small builder, JCT Option B or C is overkill. You are not running a £2 million school build. What you need is a domestic-friendly version of the same idea.
The Federation of Master Builders updated its Domestic Building Contract in 2024 to include cleaner provisions for cost variation. If you use the FMB contract, you already have a framework for this. If you write your own quotes, paste the clause above onto every one.
The reason this clause works is psychological as much as legal. Clients know the cost of living. They know steel is up. What they do not know, and what frightens them, is whether you are using the situation to charge more than you need to. A pass-through clause with evidence-of-invoice makes it clear that you are not. You are sharing the volatility with them, both ways.
For larger contracts, especially anywhere a main contractor is involved, look at indexation against the BCIS Materials Cost Index. The figure is published monthly. The clause writes itself. For deeper guidance on subcontract terms, our subcontractor contract clauses guide covers the wording that holds up when a job goes long.
Step 3: Build a margin buffer into every quote
Even with a clause and a shorter validity window, the daily small movements still grind. The honest answer is that you carry a buffer.
Take your materials line, add 5%, and call it contingency. Not as a separate line on the customer's quote. Embedded in the materials sub-total. If the prices hold, the 5% goes straight to gross margin. If they drift by 3%, you have absorbed it and still made the quote work. If they drift by more than 5%, your price-adjustment clause kicks in for the difference. That is the layered defence.
Five per cent is the working number for stable categories. For steel-heavy or imported-timber-heavy jobs, take it to 8%. For copper-heavy electrical or plumbing work, take it to 10%. These are not random numbers. They track the high-volatility category rises.
The bar below shows where a contingency typically lands across your common material categories. The percentages are starting points; adjust against your own merchant statements from the last six months.
This is not a static spreadsheet you set once. It is a quarterly review against your actual merchant tickets. If your timber merchant has held prices for four quarters, drop the buffer to 5%. If steel has moved twice in three months, push it to 12%. The system is what protects you, not the specific number.
Step 4: Talk to your suppliers earlier
Most trades only talk to their merchant about price when they are picking up materials. By then it is too late. The merchant is reacting to what they paid for the stock six weeks ago.
Two conversations are worth having.
First, ask your three main suppliers for a written price hold on bulk items quoted for specific jobs over £3,000. Most merchants will hold a price for 14 to 30 days on a written quote against a named project. They will not volunteer this. You have to ask. The smaller merchants are often more willing than the national chains because they value the relationship over the marginal pound.
Second, ask about indexed pricing on regular categories. Some merchants will offer a 5% reduction on standard stock if you commit to monthly volume. That trade-off (small discount for predictable cash) suits both sides during volatile periods.
If you run a heating or plumbing business, the Builders Merchants Federation's monthly price index is worth subscribing to. It tells you which categories are moving before your next quote does.
Step 5: Talk to your clients without losing the job
The hardest part of all this is the conversation when a price needs to move. Clients hate surprise increases. They are reasonable about explained ones.
Two principles hold.
One, never explain a price rise by telling the client what your business is doing. Explain it by telling them what the market is doing. "Cable has gone up 14% since I quoted, here is the merchant ticket from this morning" lands better than "I need to charge more." The first puts you on the client's side of the table. The second puts you opposite it.
Two, give them a choice. "Here is the new total. If that does not work, here are two changes we could make to keep it closer to the original number." Maybe that is a different fitting, a different timber grade, or a phased schedule. Most clients pick the new total once they have been offered the alternative. The choice itself reassures them that they are not being cornered.
Customers are also feeling cost pressure. Property surveys from late 2025 indicate over half of UK homeowners had paused at least one home improvement project; just over a third were reluctant to commit even when they could afford it. Acknowledging that, gently, builds the kind of relationship that absorbs a 4% adjustment without an argument. Tommy LeeZmuda has written more on the customer conversation side in our dynamic pricing playbook, and the framing translates directly.
The wider context for any of this is operational discipline. Knowing your numbers, having a system that runs, and not being one bad quarter away from a problem. Aaron McLeish lays this out fully in our benchmarking guide, and Joe McGarry's piece on the 5 warning signs of a distressed construction business is worth reading if material cost pressure has already eaten a quarter or two.
What tradespeople are saying
Recommended videos
Why Construction Costs Will Change in 2026
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Skill Builder
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MR A BUILDERS
The Looming Construction Skills Crisis
Ryan Seeley Plastering
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ConstructIQ
How to Compare Builders Quotes Properly
Home Building Hub
Frequently asked questions
The 9.5% figure is at the upper end of what we are seeing. BCIS has the all-work materials index at 3.2% year-on-year to April 2026. BMF is reporting 5.4% average price rises in Q1. Arcadis forecasts 5 to 6% for buildings work through 2026. Specific categories like structural steel, copper-heavy electrical, and imported timber are running between 8 and 13%. So 9.5% is a reasonable working number if you weight your portfolio toward those categories. For light electrical or refurbishment work with mostly stable materials, 5% is closer.
You can, and you should review your rate annually. But it is the wrong tool for material volatility. A higher day rate makes you uncompetitive on labour-light jobs and underprices you on material-heavy jobs. The risk lives in the materials line; the buffer goes in the materials line. Treat them as separate problems.
In our experience, yes, when it is written clearly and applied symmetrically. The version we recommend passes through rises above 5% with merchant evidence, and passes through falls of more than 5% the same way. That symmetry matters. Clients reject clauses that feel one-sided. They accept clauses that feel like a shared response to a market both of you can see is moving.
For specific tightly-priced jobs with named-day delivery, 7 days is reasonable and now more common. For standard work, 30 days is the new norm. Anything beyond 30 days on volatile categories needs a re-quote clause or a price-adjustment clause, otherwise you are carrying the volatility risk for your client.
If the client buys the materials direct, you are largely out of the price-risk conversation but you take on a schedule risk instead. Late or substituted deliveries can delay your labour. The fix is the same in principle: a written clause covering what happens if materials are not on site by an agreed date, and who bears the cost of the delay.
Generally no. JCT Options B and C and NEC4 Option X1 are designed for larger commercial projects with the administrative overhead to support them. For domestic work, the FMB Domestic Building Contract (updated in 2024) or a clean written quote with the SME-friendly clause earlier in this article is more practical and just as enforceable.
Add a price-adjustment clause to your quote template today. It costs nothing, it takes ten minutes, and it removes the single largest source of margin risk you have. Everything else in this article matters; nothing else matters as much as that one paragraph going into every quote you send from now on.
My verdict
Material inflation in 2026 is not the crisis some headlines make it. Three to six per cent across the board is uncomfortable, not catastrophic. The danger is in the specific categories, the long quote-to-order windows, and the absence of a written response when a £200 line item goes the wrong way. A 30-day quote validity, a five-line price-adjustment clause, and a 5 to 10% material buffer baked into every quote will protect more margin than any supplier negotiation. Run those three changes this month. Review your numbers properly next quarter. That is how a trades business stays profitable through a moving market, not because the market stopped moving, but because the business is built to absorb it. The proactive approach to pricing pays for itself by quite some margin compared to fixing it after a quarter has already gone sideways. Build it as part of how you scale the business the right way, and a bad quarter becomes a story, not the end of the business.
