You can go bust making a profit.

Start with the two people looking at your project who completely disagree.

Two verdicts, both correct

The accountant looks at the whole job. A million-dollar contract, $827,008 of cost, $172,992 of profit. A good project. He is right.

The bank looks at the calendar. In month one you paid for mobilisation, steel, and a gang, and nobody paid you anything. In month two you did it again, and the first payment — for month one's work, less retention — arrived. You are always spending before you are collecting, every month, and the shortfall stacks up. By month four you are $60,000 in the hole. The bank is also right.

Both of these are true on the same Tuesday. The project makes money and has none. Profit is a story about the end of the job; cash is a fact about this morning, and you can only spend the fact. The graveyard of construction is full of companies that were comfortably profitable on the day the cheque to the steel supplier bounced.

The two curves

Draw the money going out and the money coming in on the same axis, and you have the two most important lines in a contractor's life.

The requirements curve is money out: your cost, when you actually pay it. Wages weekly, plant monthly, the steel supplier on his terms, the subcontractor on his. It climbs as the job accelerates and flattens as it winds down.

The income curve is money in: what the client pays you, which is always later and always less. Later, because you do the work, then value it, then he certifies it, then he pays — a chain we take apart next week. And less, because every certificate has retention carved out of it.

The income curve lives below and to the right of the requirements curve for the entire job. It has to. You fund the work, then you get paid for it, and the space in between is a hole you are standing in.

Two things about that hole. The vertical distance at any moment — $60,462 at its worst, in month four — is the cash you must have available, from the bank or from your own reserves, just to keep paying people. And the area between the curves, summed over the whole job, is how much financing you are buying to stand in it.

Notice where the income curve ends

Follow the income curve all the way to the right, to the end of the job, and it does not reach a million dollars. It reaches $950,000, and it stays there.

The missing $50,000 is retention — five percent of every certificate, held back by the client as his insurance that you will come back and fix the snags. Half of it is released when the building is practically complete. The other half sits in the client's account, earning him interest, until the end of the defects period, which is a year or more after you have left site.

Look at that number again. Fifty thousand dollars. It is exactly the management reserve from Week 5 — the money that sat above your baseline, that you could never touch. Now the client is doing the same thing to you: holding $50,000 of your money, out of reach, for a year. Everyone in this industry is holding somebody else's cash, and the whole chain runs on the tension of it.

That retention is real money you have earned and cannot spend, and getting it back is its own discipline — which is a large part of next week.

The depth is a choice

Here is the part that turns cash from a worry into a tool. The hole has a depth, and you have your hands on the levers that set it.

Front-load the schedule of values, as you learned to do in Week 9, and the income curve lifts at the start — the hole gets shallower. Get your valuations certified faster, and the income curve moves left, closer to the cost. Pay your own suppliers a little slower — sixty days instead of thirty — and the requirements curve drops back. Each of those makes the hole you stand in shallower.

And two things dig it deeper: the retention the client holds, and every dollar of material you buy before you actually need it — the 78 tonnes sitting in the laydown yard from Week 10 were not just an asset, they were cash you spent early for steel you had not yet used.

Not one of those levers changes the profit by a single cent. The job still makes $172,992 whichever way you play it. They change only the timing — and timing is the entire game of cash. This is why a commercial planner thinks about the calendar of money as carefully as the calendar of work.

The hole is not free

One number to take with you. That $60,000 hole is not something you simply endure — you pay rent on it.

Carry a $60,000 overdraft for the eight months you are underwater, at eight percent, and it costs about $3,225 in interest. That comes straight out of the $172,992 profit, before a single thing has gone wrong on site, before a single bar is tied slowly. It is the price of the timing mismatch alone.

Manage the curves well and you shrink it. Manage them badly — buy early, certify late, let retention pile up unnoticed — and a comfortable-looking job quietly hands a chunk of its margin to the bank, or worse, hits a month where the money simply is not there and the whole thing stops.

Practical insight

Ask for your project's cash flow forecast — the two curves, month by month — and find the single deepest point of the gap. That number is how much cash this project must have access to at its worst moment. If nobody can tell you that number, nobody is managing the cash, and you are one slow-paying month away from finding it out the hard way.

Then find the retention line and add it up. That is your money, earned, sitting in someone else's account. If nobody is tracking when each slice of it is due back, some of it will quietly never come back at all.

Key takeaways

✔ Profit and cash are different questions. This job makes $172,992 and is $60,462 short in month four — both true at once.
✔ The requirements curve is money out; the income curve is money in. Income is always lower and later.
✔ The vertical gap is the cash you must finance; the area between the curves is what that financing costs.
✔ The income curve ends at $950,000, not a million — the missing $50,000 is retention, the same figure as Week 5's management reserve, now held against you.
✔ Five timing levers set the depth of the hole, and none of them change the profit — only when the money moves.
✔ Buying materials early (Week 10's 78 tonnes) and letting retention build both dig the hole deeper.
✔ A $60,000 hole carried eight months at 8% costs $3,225 — margin gone to the bank before anything goes wrong.
✔ Find the deepest point of your cash gap. That is the number that decides whether the project survives a slow month.

What is coming next

The income curve arrives late for a reason, and the reason has a mechanism with a name, a rhythm, and a set of rules that every contract in the world spells out in fine print.

You do the work. You value it. Someone certifies a smaller number. Retention is carved off. And then, weeks later, the money finally moves — or a notice arrives explaining why it will not.

Next week: the interim payment cycle — valuation, certification, retention, and the working capital gap that lives inside the fine print.