The Chicago Plumbing Code requires sufficient toilet facilities for employees before construction starts, at least one per 30 employees or fraction, and no floor more than four stories from a toilet. OSHA 29 CFR 1926.51 sets its own ratios. Where they differ, the stricter rule governs. Confirm with the permit office.
Key takeaways
- Chicago Plumbing Code: nobody may start construction, alteration or repair of a building without sufficient toilet facilities for employees, at least one per 30 employees or fraction of 30.
- In a multi-storey building, no floor may be more than four stories from a story with toilet facilities, which is why tall projects stage units on upper levels.
- OSHA 29 CFR 1926.51(c) sets 1 toilet for 20 or fewer workers, then 1 toilet seat and 1 urinal per 40 workers above 20, and per 50 workers at 200 or more.
- Toilets must be reachable in under 10 minutes under the OSHA rule, and an unsanitary toilet does not count toward the total.
- Where the city and OSHA numbers differ, the stricter one governs. Confirm your count with the project's permit office, and let your provider handle delivery and servicing.
What does the Chicago Plumbing Code require on a construction site?
No one may start construction, alteration or repair of a building without enough toilet facilities for employees. The code counts at least one per 30 employees or fraction of 30. Chemical closets count, and non-sewer facilities must be kept sanitary and serviced.
The City of Chicago's guidance on temporary buildings states the rule in a single sentence that does a lot of work. Before a crew starts building, altering or repairing a structure, the site must have enough toilet facilities for its employees. The code names water closets, chemical closets, privies and approved incinerators, and a rented portable toilet is the kind of unit most crews have in mind.
The count is at least one per 30 employees or fraction of 30. The words 'or fraction' matter. A crew of 31 is not 'about one', it is two. A crew of 61 is three.
Non-sewer facilities, the code adds, must be kept sanitary and serviced, and where they sit on private property they must be at least 5 feet from the property lines. That servicing is the provider's work, not the crew's. Do not move, tip or empty a unit yourself.
What does OSHA require for construction toilets?
OSHA 29 CFR 1926.51(c) requires 1 toilet for 20 or fewer workers. Above 20 it requires 1 toilet seat and 1 urinal per 40 workers, and from 200 workers up, per 50. Toilets must be reachable in under 10 minutes, and unsanitary ones do not count.
The federal rule is written in bands. A crew of 20 or fewer needs one toilet. A bigger crew needs a toilet seat and a urinal for every 40 workers, and once the crew reaches 200 the ratio loosens to one set per 50.
Two other parts of the OSHA rule are as important as the ratio. The first is distance: toilets must be reachable in under 10 minutes. On a flat warehouse lot that is easy. On a tall building it is a real constraint, because a worker on the 30th floor cannot walk to the ground in that time. The second is condition: a toilet that is unsanitary does not count toward the total.
The OSHA text is a floor for the whole country. It does not know about Chicago. That is why the next question matters.
Which rule applies when the city and OSHA differ?
Where the Chicago code and OSHA give different numbers, the stricter requirement governs. Do not pick the lower count. Tell your permit office which crew size you plan for, ask which count it accepts, and give that number to your provider when you order.
A site in Chicago is under both rules at once. The city wants a count by employees, and OSHA wants a count by workers in bands that include separate urinals. They are close but not identical, and a site manager who reads only one can come up short on the other.
The sensible approach is to work out both and use the larger. Then ask the project's permit office which count it expects. This guide cannot promise that a certain number of units will satisfy an inspector or reviewer, and nobody at the provider can either.
The table below sets the two rules side by side. It is a reading aid, not a ruling.
| Point | Chicago Plumbing Code | OSHA 29 CFR 1926.51(c) |
|---|---|---|
| Basic count | At least one per 30 employees or fraction of 30 | 1 toilet for 20 or fewer workers; above 20, 1 toilet seat and 1 urinal per 40 workers |
| Large crews | No separate band stated in the guidance we reviewed | From 200 workers, 1 per 50 workers |
| Distance | No floor more than four stories from a story with toilet facilities | Reachable in under 10 minutes |
| Condition | Non-sewer facilities kept sanitary and serviced | An unsanitary toilet does not count |
| Placement | At least 5 feet from property lines on private property | Not addressed in the guidance we reviewed |
How many units does a crew of a given size need under city code?
Count one unit for every 30 employees, rounding any remainder up. A crew of 30 needs one, a crew of 31 to 60 needs two, 61 to 90 needs three. That is the city code alone. OSHA's bands and your permit office may ask for more.
Here is the arithmetic for the city rule, worked out from the words of the code. It is a worked example, not a quote from the code, so treat it as a first pass.
Count the crew at the busiest point of the project, not the average. A framing crew, an electrical crew and a concrete pour can all overlap on one week and push the count up. If you plan only for the quiet weeks, the busy ones will outrun your units.
| Employees on site | City code minimum (computed) | Reading |
|---|---|---|
| 1 to 30 | 1 | One toilet, up to and including a crew of 30 |
| 31 to 60 | 2 | A fraction of 30 counts as a full block |
| 61 to 90 | 3 | Add one for each extra block of 30 |
| 91 to 120 | 4 | Same step, same rounding |
| 121 to 150 | 5 | Larger crews step up the same way |
What does the four-story rule mean on a high-rise?
In a multi-storey building, no floor may be more than four stories from a story that has toilet facilities. On a tall tower that means units or facilities must be provided on upper levels as the building rises, not only at ground level, so crews are never far from one.
This is the rule that changes how tall projects are run. Ground-level units are fine for the first few floors. Past that, a crew working on a high floor needs facilities within four stories of where it is standing.
Chicago has no shortage of examples. The West Loop has seen heavy redevelopment, including 900 West Randolph, a 43-story tower completed in 2023, with reports of more than 6,500 new residences coming. The Obama Presidential Center in Jackson Park was reported as nearing full height. Both are the kind of multi-year site where this rule shapes the plan.
How a provider stages units on upper floors is a matter for the provider and the general contractor to work out, including how units are lifted and where they sit. We make no promise about what is possible on any given building. Our page on high-rise construction toilets explains the questions to settle before the first floor goes up.
Where do industrial and warehouse sites fit?
The same city and OSHA rules apply to industrial building sites, but the layout differs. Warehouse and industrial lots in Bedford Park and Franklin Park have more open ground, so units sit near the work. The distance and count rules still apply, as does regular servicing.
Bedford Park is an industrial suburb near Midway Airport. About 90 percent of its land is devoted to industry, and its Belt Railway yard is described as the busiest in the world. Franklin Park touches the southern border of O'Hare International Airport, and reports say it has added more than 4.2 million square feet of new industrial space.
A big flat site is easier on the 10-minute rule, but it has its own challenge: a very large lot can put a toilet far from a distant corner of the work. Spread the units across the site, not in one bank by the gate. For crews that run long hours or shifts, tell your provider so the servicing schedule fits.
See our page on industrial and warehouse site toilets and the construction site toilets service page for the ordering side.
Does winter change how a Chicago site plans its toilets?
It can. January in Chicago averages about 25 degrees Fahrenheit, with a record low of minus 27, and lake wind adds chill. The code count does not change with the season, but cold affects how a provider delivers and services units. Raise it when you order.
The city and OSHA counts are the same in July and January. What changes is everything around them. A crew that works through a hard winter still has to reach a toilet within the OSHA time limit, and a snowed-in lot can make that walk slower and a servicing truck's approach harder.
Winter rules for freezing and anchoring are not something we found a Chicago source for, so we do not state any. Ask your provider what it does for cold-weather rentals, and what it needs from the site, such as a plowed approach and a clear pad. Our guide on portable toilets in a Chicago winter lists the questions, and the cold-weather portable toilets page covers the product side.
On a long project, plan for the season you will be in, not the one you start in. A job that begins in October and runs into spring crosses the coldest months, so mention the full timeline to the provider at the start.
What should I tell the provider when I order for a site?
Tell the provider your site address, how many employees you expect at the busiest point, the length of the project, any upper-floor staging and the access route for a truck. Ask for servicing in writing. The provider delivers and services the units, and you confirm the count with the permit office.
A site order is a bigger conversation than an event order, because the project runs for weeks or months and changes shape as it goes. Give the provider the facts above and expect to revisit them as the crew grows.
A good provider will ask what the crew looks like in the busiest week, not the average one. If your headcount changes, tell them early. Whether a provider has more units available, and when, depends on the provider, and we cannot promise a date. For work that runs a long time, see the page on long-term portable toilet rental.
- The site address and where on the lot the units may go.
- Your headcount at the busiest point, and how it will change.
- The project length and any phases that change the crew.
- Any upper-floor or staged placement needed under the four-story rule.
- The route and clearance a truck needs to reach the spot.
- The servicing schedule you want, written into the quote.
Frequently asked questions
Do portable toilets count as toilet facilities under Chicago code?
Yes. The code names water closets, chemical closets, privies and approved incinerators as acceptable facilities, and a portable toilet is a chemical closet. Non-sewer units must be kept sanitary and serviced, and on private property sit at least 5 feet from property lines.
How far can a worker be from a toilet under OSHA?
Under 29 CFR 1926.51(c), toilets must be reachable in under 10 minutes. On a tall building that rule works with Chicago's four-story limit to push toilet facilities up with the work. An unsanitary toilet does not count toward the total, so servicing matters.
Is the city count or the OSHA count higher for a crew of 100?
We do not compute that here because the guidance leaves details to the permit office. Work out both counts, use the larger, and ask the permit office to confirm. The stricter rule governs, and your provider needs the final number.
Can my crew empty or move the unit when it gets full?
No. Do not move, tip or empty a portable toilet yourselves. Servicing is the provider's job, done with the right equipment. If units fill faster than the schedule expects, tell the provider so they can adjust visits.
Does a film crew follow construction rules?
Not in the same way. A film shoot on a street or sidewalk needs a Chicago Film Office permit, which takes a minimum of 3 full business days to process. The toilet question there is a crew-comfort and base-camp one. See the film shoot restrooms page.
Sources
- City of Chicago – Temporary buildings and construction requirements, Chicago Plumbing Code reference
- OSHA – Standard interpretation on toilet facilities at construction sites
- OSHA – 29 CFR 1926.51, Sanitation
- City of Chicago – Chicago Film Office, city services form
This guide is general information for Cook County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.