Use the free construction site welfare calculator
Available on all plans
The construction site welfare calculator shows the minimum number of toilets and washbasins for the people on your site, using Tables 1 and 2 in HSE's guidance L24. It also lists the other welfare facilities CDM 2015 Schedule 2 requires, such as drinking water and a rest area. It's free and you don't need an account. You can also find it on the free tools page.
Work out your site's welfare
Open the construction site welfare calculator from the free tools page
Enter the Most people on site at any one time
Tick Separate toilets for men and women if you will provide separate toilets, then enter How many of them are women?
Leave it unticked if everyone shares toilets, each in its own room that locks from the inside.
Answer Is there mains water and drainage on site?
Tick the other boxes that apply to your job
The work heavily soils people's face, hands and forearms raises the washbasins. Temporary or mobile work, such as highway, utility or repair work adds a note on using existing facilities.
Read the result under Toilets and Washbasins, then the Also provide list
With no mains water, the result also shows how many portable chemical toilets to provide: HSE's guidance figure for a 40-hour week, or the L24 Table 1 number where that is higher.
Try the worked example
Click Use the worked example to load the example from the calculator page: 30 people, 4 women and 26 men, separate toilets and no mains water. Click Clear to start again.
What the result means
The numbers are minimum numbers from HSE's tables. More may be needed, for example if everyone takes breaks at set times. The calculator page shows both tables and explains where every number comes from, with links to the sources.
Frequently asked questions
Do I need an account to use the welfare calculator?
No. The calculator is free to use on our website without signing in.
Is what I enter sent to The Site Book?
No. The calculator works everything out in your browser. The numbers and answers you enter are not sent to us or saved.
Are the toilet numbers a legal requirement?
No. CDM 2015 Schedule 2 requires suitable and sufficient toilets and washing facilities but gives no numbers. The numbers come from the tables in HSE's guidance L24, which HSE says give a guide to the numbers needed on a construction site. They are minimum numbers, and your site may need more.
Which number of people should I enter?
Enter the most people likely to be on site at any one time, not the total number of people who work there over the whole job.
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