
The average general contractor (main contractor in the UK) nets somewhere between 5 and 6 cents on every dollar of revenue. Run a million dollars in jobs this year and, after the trades, the materials, the overhead, and the tax, you take home somewhere around $50,000 to $60,000. The client paid a million. You kept the change. (Figures in USD throughout - the model and the math are identical in any currency.)
That is not a bad market story. It is a pricing, overhead, and systems problem - and every one of those is fixable. When I started running construction the smart way, the model I kept coming back to was construction arbitrage: a way of running a construction business that is built around controlling the margin by design, not by accident. Whether you are on the tools today or running a crew, the levers in this post work the same way.
Why most contractors run thin margins
The problem is usually not the market, not the competition, and not the economy. It is one of three things:
- Underbidding to win. You price low to beat a competitor, win the job, then discover the margin disappeared on day two when labour ran over by 15 percent. You finish the job, get paid, and barely cover your costs.
- Confusing markup with margin. A 25 percent markup on cost is not a 25 percent profit margin. It gives you 20 percent margin. The difference destroys your numbers if you are not tracking it - and most contractors are not.
- Taking every job that calls. Not every project is worth doing. Low-value, scope-creep-heavy, awkward-access jobs eat the same hours as a clean high-margin job - but pay a fraction of the return.
Most contractors do not have a pricing problem. They have a job selection problem. They say yes to everything and wonder why the margin is thin.
@mointhemarket
The margin math every contractor must know
The construction industry has a well-known shorthand: the 10-10 rule. Ten percent for overhead, ten percent for net profit, giving a 20 percent total markup on direct job costs. The National Association of Home Builders (NAHB) points to it as a standard baseline for a healthy operation. Here is what the numbers actually look like at different markup levels:
| Markup on cost | Price on a $10,000 job | Your actual margin |
|---|---|---|
| 15% | $11,500 | 13% |
| 20% | $12,000 | 16.7% |
| 25% | $12,500 | 20% |
| 33% | $13,300 | 25% |
| 50% | $15,000 | 33% |
Most contractors running thin margins are selling at 15 to 20 percent markup and calling it profit - when the real gross margin is closer to 13 to 17 percent, before a single overhead cost is touched. Once insurance, fuel, software, vehicle costs, and office expenses come off, the 13 percent gross has turned into a 5 percent net. That is the industry average for a reason.
Five ways to increase your construction profit margin
- 01Raise your markup on subcontractor work. Industry practice puts the typical markup on sub costs at 10 to 25 percent, with 15 to 20 percent being most common in residential work. If you are coordinating schedules, managing clients, carrying liability, and standing behind the result when something goes wrong - and you are charging less than 15 percent on top - you are giving the value away.
- 02Price the outcome, not just the cost. A kitchen remodel that adds $80,000 to a property's resale value is worth more than materials plus a day rate. Know what the outcome is worth to the client and price from there. Market value pricing, not cost-plus, is how operators command real margins.
- 03Cut overhead before cutting your quote. Small construction firms typically run overhead at 20 to 25 percent of revenue. Every point of overhead you cut - unnecessary subscriptions, underused equipment, inefficient admin processes - goes straight to net margin without touching a single quote.
- 04Run a post-job cost review on every project. Compare estimated versus actual costs. Most margin erosion is invisible until after the fact. Build the post-job review into every project and you will find the leak within two or three jobs.
- 05Stop discounting to close. Discounting is the fastest way to destroy a margin. Instead of going lower, go deeper on value: tighter timeline, cleaner site, stronger warranty, better client communication. Price holds better when the value is clear.
Job selection is a margin strategy
The best operators I have seen turn down more work than they take on. That sounds backwards when the diary is empty - but the logic is tight.
High-margin jobs share common traits: a clear scope defined before the contract is signed, a client who makes decisions fast, straightforward site access, standard materials, and a realistic timeline. Low-margin jobs look like the opposite: vague scope, slow clients, difficult access, bespoke materials, and a client who is already pushing on price before the ink is dry.
The subcontracting model and what it does to margins
Here is where the margin picture changes completely for operators who understand the construction arbitrage model.
The moment you stop being the person on site doing the work and start being the person who sources the client, prices the job, and manages the subcontractor network that delivers it - you stop capping your margin by your own daily output. You start earning on the spread between what the project sells for and what the subcontractor network delivers it for. That spread is structural. It exists on every job you price correctly.
Operators running this model stack projects in parallel - each with a planned margin built in from day one. One person managing four jobs at a margin of 25 percent earns dramatically more than one person doing one job at 10 percent, working twice as hard. The model change outperforms any single pricing lever.
Gross margin vs net margin - know where your money goes
Two numbers tell you the real health of your business. Gross margin is revenue minus the direct cost of the job - labour, materials, and subcontractor costs. Net margin is what is left after overhead is paid too: insurance, vehicles, software, office, accounting, marketing.
Industry data puts average gross margins for general contractors at 12 to 16 percent, and average net margins at 5 to 6 percent. The gap - 6 to 10 points - is overhead. Every percentage point of overhead you remove goes straight to net margin, with no change to your quotes at all. Most businesses have more fat in their overhead than they realise until they look for it deliberately.
What a healthy margin actually looks like
Industry guidance from multiple construction finance sources consistently points to 8 to 10 percent net as the target for a well-managed general contracting operation. Top performers - those who have built reliable systems, selected jobs consistently, and kept overhead lean - hit 10 to 12 percent net on a sustained basis.
That gap between 5 and 12 percent sounds like detail until you run the numbers on $1,000,000 in revenue. At 5 percent, you keep $50,000. At 12 percent, you keep $120,000. Same jobs. Same market. Same crew. Different result - because of how the business is priced and run.
The operators who close that gap are not working harder. They are pricing smarter, selecting better jobs, controlling overhead, and - when they are ready - shifting to a model where margin is built in structurally rather than fought for job by job. If you want to understand how that model works at the level of numbers, the full breakdown is at constructionarbitrage.com.
The contractors who crack the margin game build real businesses - not just jobs with a logo. Contractor Club is for the ones who want to play it properly. If you think you belong in the room, leave your details.
Request entry to Contractor Club⟶The bottom line
Margin does not come from working harder. It comes from knowing the math (markup is not margin), pricing the outcome not just the cost, cutting overhead before cutting quotes, picking the right jobs, and building the business so it runs on a system rather than a person. The industry average is 5 to 6 percent because most operators are running on defaults. The players who change the defaults change the number. That is the whole game - and only players know.
Frequently asked questions
What is a good profit margin for a construction business?+
Industry data puts the average net margin for general contractors at 5 to 6 percent. A healthy, well-run operation should target 8 to 10 percent net. Top performers with strong systems, recurring work, and disciplined job selection consistently hit 10 to 12 percent net. The gross margin (before overhead) for most general contractors sits between 12 and 16 percent.
What is the difference between markup and margin in construction?+
Markup is calculated on your cost. Margin is calculated on your selling price. A 25 percent markup on a $10,000 job gives you a $12,500 price - but your margin is $2,500 divided by $12,500, which is 20 percent, not 25. Confusing the two is one of the most common ways contractors underprice their work and wonder where the money went.
What is the 10-10 rule in construction?+
The 10-10 rule, widely referenced by the National Association of Home Builders (NAHB), means targeting 10 percent for overhead and 10 percent for net profit - a combined 20 percent markup on direct job costs. It is a starting point, not a ceiling. Operators with lean overhead and strong job selection can push well past it.
How do I increase my construction profit margin without raising prices?+
Cut overhead (the gap between gross and net margin is almost entirely overhead), do better job costing so you know where margin leaks, stop taking low-value jobs that eat the same hours as profitable ones, and raise your markup on subcontractor work to at least 15 to 20 percent. Better job selection is often faster than a price increase.
What markup should a general contractor add on subcontractor work?+
Industry practice puts the typical markup on subcontractor costs at 10 to 25 percent, with 15 to 20 percent being most common in residential construction. The markup covers coordination, schedule management, client communication, liability, and the risk that if a sub underperforms, it is your problem to fix. If you are doing all of that and charging less than 15 percent, you are giving away the value.
What does construction arbitrage have to do with profit margins?+
Construction arbitrage is the model of running a construction business as the general contractor - sourcing work, directing subcontractors, and keeping the margin between what the project sells for and what it costs to deliver. Operators who run it well do not cap their margin by their own daily output. They stack projects in parallel, each with a planned margin built in from day one, which is why the margin profile looks very different from a one-man-on-the-tools operation.
The human behind The Playbook
mointhemarket Managing construction businesses across continents - with full location freedom. Running several at once. Bought and sold many more.
1,284 likes
buildwithleon This is the most honest breakdown of the model I've seen. No fluff.
site_to_ceo Bought my second business off the back of this thinking. Wild that more people don't get it.
the.margin.method "Price outcomes, not time" - putting that on the wall 🔥
Go deeper
Learn the model, then get in the room
The full breakdown of construction arbitrage lives on our sister site, constructionarbitrage.com. When you want the operators who actually run it, join the Construction Arbitrage Players community.
My book The Family Secret - how construction arbitrage really works - is coming soon.
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