How Much Profit Should Builders Make? (UK Margins Guide 2026)

Profit margin is the percentage of revenue left after all costs — materials, labour, subcontractors, overheads, and expenses. For UK builders, a healthy net profit margin typically falls between 15–25%, though this varies significantly by job type, business size, and how accurately you quote and track costs.

Ask ten builders what margin they make and you'll get ten vague answers. Most know roughly what they turn over in a year, but far fewer can tell you the actual profit on their last job. That gap between revenue and real profit is where most building businesses quietly bleed money — and it's almost always a tracking problem rather than a pricing problem.

This guide breaks down what realistic margins look like for UK builders, how to calculate them properly, and what you can do to protect yours.

1 What's a Realistic Profit Margin for Builders?

There are two numbers that matter: gross margin and net margin. Gross margin is what's left after direct job costs (materials, labour, subcontractors). Net margin is what's left after you also subtract overheads — your van, insurance, tools, accountant, phone, fuel, and everything else that keeps the business running whether you're on a job or not.

For most UK builders, realistic benchmarks look like this:

• Gross profit margin: 30–40%. This is revenue minus the direct cost of delivering the job. If you charge £10,000 and materials plus labour cost £6,500, your gross margin is 35%.
• Net profit margin: 15–25%. This is what's actually left in your pocket after every business cost is accounted for. A builder turning over £200,000 a year with a 20% net margin takes home £40,000 in profit — before personal tax.

If your net margin is consistently below 10%, something is wrong. You're either underpricing work, not tracking costs properly, or your overheads are too high relative to your turnover. Above 25% net is excellent and usually means you're quoting accurately, managing jobs well, and keeping overheads tight.

2 Why Most Builders Don't Know Their Real Margin

The most common problem isn't low margins — it's not knowing what your margins actually are. Many builders track what comes in (invoices, payments) but not what goes out on a per-job basis. They know they turned over £180,000 last year and had roughly £30,000 left, but they can't tell you which jobs made money and which ones lost it.

This matters because averages hide the truth. You might make 30% on kitchen refits and lose 5% on insurance repair work — but if you're only looking at the annual total, you'll never spot that pattern. You'll keep taking the jobs that lose money and wonder why the bank balance doesn't reflect how hard you're working.

Per-job profit tracking changes this entirely. When you can see the actual margin on every project — not just a year-end average — you start making better decisions about which work to quote for, how to price it, and where the money is actually going. Tools like VoxTrade track costs against each project automatically, so you can see your real margin on every job without spreadsheet gymnastics.

3 Markup vs. Margin — the Confusion That Costs You Money

Builders regularly confuse markup and margin, and the difference isn't just academic — it directly affects your profit. Here's the distinction:

• Markup is the percentage you add on top of your costs. If a job costs you £10,000 and you add 25%, you charge £12,500.
• Margin is the percentage of the final price that is profit. On that same £12,500 job, your profit is £2,500 — which is 20% of £12,500, not 25%.

The numbers feel similar but compound over a year. A builder who thinks they're making 25% margin because they apply a 25% markup is actually making 20%. On £200,000 turnover, that's a £10,000 difference — real money that was never there to begin with.

Quick rule: a 25% markup equals a 20% margin. A 33% markup equals a 25% margin. A 50% markup equals a 33% margin. Always calculate margin on the selling price, not the cost price.

4 How to Calculate Margin on a Job — Worked Example

Let's walk through a real example: a £15,000 kitchen refit in a semi-detached house in the Midlands. The builder is doing strip-out, first fix, plastering (subbed out), fitting the new kitchen, tiling, and making good.

Net margin = £4,000 ÷ £15,000 = 27%. That's a healthy margin for a kitchen refit. The key is that overheads are included — not just the obvious costs of materials and labour. Many builders would look at this job, subtract £4,000 materials and £5,000 labour, and think they made £6,000 (40%). But the real figure, once you account for the van, insurance, and other running costs, is £4,000 (27%).

The only way to know your real margin is to allocate overheads to each job. A simple method: total your annual overheads, divide by the number of working days in the year, and charge that daily overhead rate against each project based on how many days it takes.

5 Why Margins Vary by Job Type

Not all building work carries the same margin, and understanding this helps you decide which jobs to chase and which to leave.

• New builds tend to have lower net margins (10–15%) because they're often competitively tendered, long-duration, and price-sensitive. The upside is predictability — fewer surprises behind walls.
• Renovations and refurbishments typically carry higher margins (20–30%) because they're harder to compare like-for-like, require more skill, and customers value experience and reliability over the lowest price.
• Maintenance and small works can be highly profitable per hour (30%+) but are harder to fill a schedule with. The overhead-to-revenue ratio is worse because of travel time and admin per job.
• Insurance work often has the thinnest margins because the insurer dictates pricing through scheduled rates. Some builders use it as filler work between better-paying jobs; others avoid it entirely.

The sweet spot for many sole traders and small building firms is renovation work in the £10,000–£50,000 range. These jobs are big enough to be efficient but small enough that you're not competing against large contractors on price alone.

Common Margin Killers

Even builders who quote well can see their margins disappear during the job. These are the most common causes:

• Underquoting. Rushing the quote, forgetting to walk the site properly, or pricing from memory rather than current supplier costs. A quote that's 10% too low wipes out your entire profit on most jobs.
• Scope creep. "While you're here, could you also..." If extra work isn't priced and agreed in writing before you do it, you're working for free. Small additions compound across a project.
• Not tracking expenses. Receipts stuffed in the van door, materials bought on a personal card, cash tips runs that never get logged. If you don't capture every cost, you can't calculate your real margin. VoxTrade's receipt scanning lets you photograph every receipt on site and it's automatically logged against the right project — no end-of-month shoebox sorting.
• Forgetting overheads. Pricing jobs based on materials + labour alone and treating the £15,000–£25,000 a year in overheads as "just part of running a business." Those overheads come directly out of your profit if they're not built into your prices.
• Rework and callbacks. Poor-quality work that needs fixing, or finishing details missed during the job that require a return visit. Each callback costs you a half-day of unbilled time.

How to Improve Your Margins

Improving your margin doesn't necessarily mean charging more — it often means wasting less, quoting more accurately, and understanding where money actually goes.

• Quote accurately from site. Visit every job before quoting. Walk through the work methodically and price each element. Voice quoting tools like VoxTrade let you describe the job out loud during the site visit and generate an itemised quote before you leave — which means fewer forgotten items and less underquoting.
• Track every expense against the job. Materials, subcontractors, skip hire, parking permits, tip runs — every cost. If it's not logged, it's invisible, and invisible costs eat your margin.
• Review per-job profitability monthly. Look at what you quoted versus what it actually cost. Over three to six months, patterns emerge: maybe your plastering estimates are always 15% low, or you consistently underestimate days on bathroom refits. Fix the pattern and your margins improve automatically.
• Price your overheads into every job. Calculate your daily overhead cost and add it to every quote. This is money you will spend whether you include it or not — the only question is whether the customer pays for it or you do.
• Manage scope tightly. Document what's included in the quote and what isn't. When the customer asks for extras, price them before you do them. A simple "that's outside the original quote — I can do it for an additional £X" protects your margin and sets professional expectations.

The Bottom Line

A well-run building business should be making 15–25% net profit on the work it takes on. If you're below that range, the cause is almost always one of three things: underquoting, untracked costs, or overheads that aren't priced into jobs. None of these are hard to fix — they just require a system.

Start by calculating your actual margin on your last three completed jobs. Include every cost — not just the obvious ones. If the numbers surprise you, that's useful information. It means there's profit sitting in your business that you're currently giving away, and the fix is better tracking, not harder work.

For more on quoting and pricing, see our guides on how to quote a building job and common quoting mistakes tradespeople make.