Running the business
Labour time from area and productivity
- where
- working days on site
- area (m²)
- productivity per person (m²/day)
- people on the job
- extra time for setting up and clean-down (days)
Explain this equation
Estimates how many days a job will take on site from its area and your productivity. Use it to book jobs and plan visits.
A is the area, Pd the m² one person completes per day, and n the number of people, so Pd × n is the crew's daily output. Ts is extra time for setting up, beading and clean-down. Tw is the working days on site.
Time is work divided by rate, plus a fixed allowance that does not depend on area.
Sense check: 60 m² at 20 m² a day plus half a day for setting up is 3.5 days. Two people at 15 m² a day each on 120 m² with a day's extra time is 5 days.
Watch out: this excludes drying time between coats and weather delays, and two people rarely work at exactly double speed in small rooms.
Estimates how many days a plastering job will take from its area and your productivity norms.
Enter your values to see the result.
Good to know
Productivity is an input because it varies widely with the work: skimming open board walls is much faster than two-coat work on masonry, ceilings, or rooms with many reveals and angles. Use your own records and compare with published labour constants. Remember drying time between coats on backing plasters when booking the next visit.
Common mistake
Assuming two people halve the time. On small rooms they get in each other's way and mixing becomes the bottleneck; use a lower productivity per person for crews.
Limits
Linear estimate. Excludes drying between visits, travel and weather delays on render.
Sources
Results are calculations from the published methods and manufacturer figures shown, and depend on the data you enter. Always follow the manufacturers’ system and product data, BS 8212, BS EN 13914 and Building Regulations. Coverage rates vary by product, background and thickness. Check prices, VAT and CIS rules with your own records and HMRC.