Hour estimates go wrong in a consistent direction: people price the visible work and forget the invisible work. Rolling a wall or laying a floor is the part you can picture, so it is the part that gets estimated, and it is typically under half the time. The rest is preparation — clearing, protecting, filling, sanding, priming — and then the detail pass, and then cleanup, which nobody budgets at all. This splits a job into those four phases, turns man-hours into calendar days for the crew size you have, and prices each phase separately so you can see which one is actually costing you.
Area, crew and rate
The field is rarely half the job. This splits the hours into the four phases.
Painting about 0.25 to 0.35. Laying laminate about 0.2. Tiling 0.6 to 1.0.
Result
The four phases, and why the first one is the largest surprise
Every trade job decomposes into the same four things. Preparation is everything that happens before the material goes on: clearing the room, protecting what stays, stripping or sanding, filling, priming, setting out. Main work is the part the job is named after. Detail is the cutting in, the edges, the second pass, the scribing, the bits that take as long as the field and cover a tenth of it. Cleanup is waste removal, washing tools, and putting the room back.
On a well-run job these run roughly 28 / 44 / 18 / 10 percent. The number that consistently shocks people is the first: preparation is more than a quarter of the hours, and on a job in poor condition it is more than half. It is also the only phase that pays for itself, because a well-prepared surface needs less detail work and fewer coats.
Man-hours are not calendar days
A ninety-square-metre floor at 0.32 hours per square metre is 28.8 man-hours. One person takes three and a half days; two people take under two. Wrongly assuming the second is how schedules slip, and the mistake is rarely symmetric — adding people beyond about three on a single room produces diminishing returns, because they get in each other's way and the detail phases do not parallelise.
The phases also parallelise differently. Main work splits cleanly across a crew. Preparation partly does. Detail and cleanup barely do at all, which is why a four-person crew does not finish in a quarter of the time of one person, even though the man-hours are identical. If you are pricing by the day rather than the hour, this matters more than anything else on the page.
Two people on a normal room is usually the sweet spot: enough to share the heavy work, few enough that nobody is waiting.
Beyond three, add a second room rather than a fourth person. Parallelising across rooms works; parallelising within one does not.
What the hourly rate does and does not buy
The rate is the most visible number and the least informative. A higher rate with a better coverage rate per hour is usually cheaper in total than a low rate with a slow worker, and the only way to see it is to compare total cost rather than hourly cost. This is the single most useful thing a breakdown like this does: it makes the trade-off between rate and speed visible.
It also makes the case for doing preparation yourself. Preparation is the least skilled and most time-consuming phase, it does not need the expensive tradesperson, and it is more than a quarter of the hours. Clearing, protecting, filling and sanding yourself can remove a genuine quarter of the labour bill without touching the quality of the finished work.
| Trade | h/m² | Notes | Where the time goes |
|---|---|---|---|
| Painting, prepared walls | 0.25 | Two coats, rolling | Cutting in dominates |
| Painting, including prep | 0.35 | Filling and sanding | Preparation dominates |
| Laminate flooring | 0.20 | Floating floor, straight rooms | Cutting around edges |
| Engineered wood, glued | 0.45 | Adhesive and acclimatising | Setting out and gluing |
| Ceramic wall tiling | 0.70 | 300x600, straight lay | Cutting and setting out |
| Natural stone tiling | 1.00 | Sealing and sorting | Handling and layout |
| Plastering, skim | 0.50 | Two coats | Second coat and trowelling |
A worked example
- Base hoursNinety square metres at 0.32 hours per square metre is 28.8 hours.
- DifficultyNormal conditions multiply that by 1.25, giving 36 man-hours.
- Split by phaseThat is 10.1 hours preparing, 15.8 doing the main work, 6.5 on detail and 3.6 clearing up.
- Turn it into daysTwo people working eight-hour days means 18 hours each, or 2.25 days on site.
- Price itAt $38 an hour the labour is $1,368, which is $15.20 per square metre — and preparation alone is $383 of it.
Three hundred and eighty dollars of preparation is the number to stare at. It is the single largest discretionary line on the job: the part you can genuinely do yourself, the part that most affects how the finish looks, and the part that everyone leaves out of an estimate.
Where the estimate breaks
The hours-per-square-metre figure is the whole model, and it is the input most likely to be wrong. It varies by trade, by material, by room shape and by who is doing it, and the ranges in the table above are wide for good reason. If you have a figure from someone who has done the job before, use it instead of a table.
The phase split is fixed at 28/44/18/10 and it is a generalisation. A tiling job has a much heavier setting-out and cutting component than a flooring job, and a job that includes demolition has a preparation phase that dwarfs everything else. Treat the split as a starting shape rather than a measurement.
Nothing here accounts for the calendar. Material lead times, drying and curing, inspection visits and the simple fact that a job rarely runs eight solid hours a day all push the elapsed time out beyond the working days. If the sequence matters, the renovation timeline turns working days into calendar days with drying time and weekends in it, and the paint cost figure shows the same phase logic applied to a single trade with materials included.
Finally, the crew divisor assumes everyone works the whole time. On a real job the second person is frequently waiting for the first, and on small rooms frequently in the way. The calendar days figure is optimistic, and it gets more optimistic the more people you add.
Do
- Use a real hours-per-square-metre figure if you have one from experience.
- Multiply for difficulty: occupied, cut-up and high work all cost time.
- Convert man-hours to days using the crew you actually have.
- Consider doing the preparation yourself — it is the largest discretionary slice.
- Compare total cost, not hourly rate, when weighing speed against price.
Avoid
- Treating man-hours as if they were calendar hours.
- Assuming four people finish in a quarter of the time.
- Budgeting the main work and forgetting preparation and cleanup.
- Comparing tradespeople on hourly rate alone.
- Expecting an eight-hour day to contain eight hours of work.
How the figures are produced
Area is multiplied by hours per square metre to give base hours, and base hours are multiplied by the difficulty factor to give total man-hours. Those are split into four phases by fixed shares, and each phase is priced at the hourly rate. Calendar hours are man-hours divided by crew size, and days are calendar hours divided by the working day. The bar splits the labour cost by phase, so the largest slice is visible at a glance.
Questions people ask
Why is preparation such a big share?
Because it is slow, unglamorous and unavoidable. Clearing, protecting, filling, sanding and priming happen before anything visible changes, and on a surface in poor condition they take longer than everything after them.
Can I cut the preparation?
You can do it yourself, which is the usual saving. You should not skip it: a surface that is not prepared takes more coats and needs more detail work, so the time comes back with interest.
Why does adding a third person not help much?
Because the detail and cleanup phases do not parallelise, and because people get in each other's way in a normal-sized room. Two is usually the optimum.
Is the difficulty factor enough?
It covers the common cases. Demolition, structural surprises and anything involving scaffolding need their own line rather than a multiplier.
Should I price by the hour or by the day?
By the hour for small, well-defined jobs; by the day where the working day is interrupted or the scope is uncertain. Day rates shift the risk to whoever is paying.
What about materials?
Not included here — this is labour only. Add materials separately, and remember that the labour figure is usually the larger of the two on skilled trades.