Modular Restroom Buildings for Commercial and Industrial Spaces
Prefabricated indoor restrooms for warehouses and plants, plus freestanding restroom buildings for yards and gates, laid out to your headcount and code.
Call (800) 326-4403 or email Sales@MH-USA.com
Any Setting
Indoor or Outdoor Buildings
Any Layout
Single to Multi-Fixture
4 to 8 Weeks
Typical Lead Time, Subject to Confirmation
Quoted
Per Configuration
What is a modular restroom building?
A modular restroom is a factory-built room or building with the walls, door, ventilation and fixture layout planned before it arrives. It can be built inside a warehouse or plant, where it connects to the building’s water and drain lines, or as a freestanding building outside.
Commercial and industrial sites add them when headcount grows, when the existing restrooms are too far from the work area, or when a conventional bathroom addition would mean weeks of trades inside an operating building.
Restroom fixture counts are set by the plumbing code your jurisdiction adopts, and OSHA’s sanitation standard requires employers to provide toilet facilities (29 CFR 1910.141). This page is part of our in-plant and industrial modular buildings range; restrooms can also be combined with modular in-plant offices and break rooms in one building.
Modular restroom configurations
Layouts start from how many people use the room, where it sits and what it connects to.
Multi-fixture employee restroomsSeparate stalls, urinals and a row of sinks for shift workers, sized to your headcount and code.
Single-user restroomsOne toilet and sink in an accessible single-user room, often next to an office or lactation room.
Restroom and change room combosRestrooms joined to locker or change rooms for crews who change at the start and end of a shift.
Exterior restroom buildingsFreestanding buildings with a weather roof for yards, gates and sites far from the main building.How many toilets do you need? OSHA and plumbing code fixture counts
Two sets of rules usually apply. OSHA’s sanitation standard (29 CFR 1910.141) sets a minimum number of water closets by the number of employees of each sex. The plumbing code your jurisdiction adopts sets fixture ratios by occupancy. Design to whichever requires more.
| Employees (per sex) | Minimum water closets (OSHA Table J-1) |
|---|---|
| 1 to 15 | 1 |
| 16 to 35 | 2 |
| 36 to 55 | 3 |
| 56 to 80 | 4 |
| 81 to 110 | 5 |
| 111 to 150 | 6 |
| Over 150 | 1 more for each additional 40 employees |
Where a restroom is used by only one person at a time and locks from the inside, separate rooms for each sex are not required under the OSHA rule. Where a toilet room is not used by women, urinals can replace some water closets, but water closets cannot drop below two thirds of the minimum.
| Model plumbing code ratio | Factory and industrial | Business (offices, light industrial) |
|---|---|---|
| Water closets | 1 per 100 | 1 per 25 for the first 50, then 1 per 50 |
| Lavatories | 1 per 100 | 1 per 40 for the first 80, then 1 per 80 |
| Drinking fountains | 1 per 400 | 1 per 100 |
| Service sink | 1 | 1 |
Ratios shown are from the International Plumbing Code minimum fixture table; states and cities amend it, and occupant load is split evenly between sexes before the ratios are applied. Your plumber, engineer or code official confirms the final count, and the layout is drawn to that number.
Indoor modular restrooms for warehouses and plants
Inside a building, the main questions are where the drain goes and how far the room is from existing water and sewer lines. If a floor drain or sewer line is close, the room ties in by gravity. If not, an above-floor pump or macerating system can avoid cutting a trench in the slab; your plumber confirms what the code and fixture count allow.
Exhaust fans, lighting and outlets are built into the panels, and a ceiling closes the room. Ventilation is ducted or fanned to the outside or a return per your mechanical design.
| Planning item | What to decide |
|---|---|
| Fixture count | Based on headcount by shift and your adopted plumbing code; your plumber or engineer confirms |
| Accessibility | Accessible stall or single-user room with clearances, grab bars and an accessible door |
| Drain path | Gravity to an existing line, a new line cut into the slab, or an above-floor pump system |
| Water heating | Point-of-use heaters at sinks or a tank, depending on fixtures |
| Ventilation | Exhaust fan to the outside or as your mechanical design requires |
| Finishes | Moisture-resistant wall finishes, sealed floor, solid-surface or stainless counters |
Accessible restroom planning checklist
Most new commercial restrooms need at least one accessible stall or single-user room. Common dimensions from the 2010 ADA Standards for Accessible Design that drive the floor plan:
| Item | 2010 ADA Standards reference point | Why it matters for a modular room |
|---|---|---|
| Turning space | 60-inch diameter circle or a T-shaped space | Sets the minimum width of a single-user room |
| Water closet clearance | 60 inches wide, measured from the side wall | Drives stall and room width |
| Toilet centerline | 16 to 18 inches from the side wall | Locates the drain in the plumbing wall |
| Grab bars | Side wall 42 inches long minimum; rear wall 36 inches minimum | Wall panels need backing where bars mount |
| Lavatory | Rim or counter no higher than 34 inches, with knee clearance | Sets sink and counter height |
| Door | 32-inch minimum clear width, with maneuvering clearance | Sets door size and swing |
Your designer or code official confirms the requirements for your project, including state amendments. Because backing, drains and door openings are planned on the drawings, accessible layouts are easiest to get right before fabrication.
Exterior restroom buildings
Freestanding restroom buildings serve truck gates, yards, parks and sites where the main building is too far away. They need a weather roof, insulation for the climate, freeze protection for water lines and a foundation or pad with utility stubs in place before delivery.
Small buildings can ship complete and be set by crane; larger ones ship as panels. See prefabricated exterior buildings and foundation options.
Florida, coastal and high-wind sites
Exterior restroom buildings in Florida are designed and permitted under the Florida Building Code, which sets wind loads by location, with the strictest requirements in the high-velocity hurricane zone. Coastal sites elsewhere face similar wind and corrosion demands. Tell us the site address early so the structure, anchorage, doors and windows are designed for the right loads, and plan for permit review of the drawings.
Construction and fixtures
Wall panels can carry factory electrical boxes and conduit in the joints, so outlets, switches and lighting are in place when the room is assembled. Plumbing walls are planned on the drawings so supply and drain lines land where the fixtures go.
Commercial fixtures, partitions and accessories are specified per project. Ask for water-efficient fixtures, touch-free faucets and vandal-resistant hardware where needed. Detail on electrical options and flooring options.
Construction options compared: panelized, precast concrete and wood-frame
Prefabricated restroom buildings come in three main construction types. We supply panelized steel-framed buildings through our manufacturer partner; the comparison below helps you check that it is the right fit.
| Question | Panelized modular (what we supply) | Precast concrete | Wood-frame modular |
|---|---|---|---|
| Best fit | Indoor restrooms in plants and warehouses; exterior buildings at gates and yards | Parks, trailheads and public sites with vandalism risk | Sites where a towable or trailer-style unit is acceptable |
| Indoor installation | Yes, assembled inside an existing building | Rarely, due to weight | Rarely |
| Delivery | Pre-assembled or knock-down panels | Set in sections by crane | Delivered whole on a chassis or trailer |
| Relocation | Can be disassembled and set up again | Possible with a large crane | Towable units move easily |
| Interior finishes | FRP, vinyl-covered gypsum or other facings | Sealed concrete or coatings | Varies by builder |
Modern modular restroom finishes
- Walls: FRP or vinyl-covered gypsum facings that wipe clean; impact-resistant faces where carts pass.
- Floors: sealed or seamless floors with a cove base so water does not reach panel joints.
- Fixtures: wall-hung toilets and sinks for easier cleaning, touch-free faucets and flush valves, water-efficient fixtures.
- Partitions and counters: solid plastic or powder-coated partitions; solid-surface or stainless counters.
- Lighting and air: LED fixtures with occupancy sensors and an exhaust fan sized for the room.
What drives modular restroom cost
Pricing depends on size, fixture count, finishes and site conditions, so every restroom is quoted per configuration. These are the biggest drivers.
See the modular building cost guide for what a quote includes and what is usually by others.
What a modular restroom quote includes and what is by others
| Usually in the building quote | Usually by others (your contractors) |
|---|---|
| Wall panels, ceiling, doors and hardware | Permits and plan review fees |
| Plumbing wall framing and fixture layout on drawings | Final water, drain and vent connections by a licensed plumber |
| Factory electrical boxes, lighting and exhaust fan | Electrical feed from your panel by a licensed electrician |
| Fixtures and partitions, when specified | Slab cutting, trenching or a pump system, if needed |
| Freight and installation, when quoted | Foundation or pad for exterior buildings |
Asking for both columns up front makes quotes comparable and avoids surprises on modular restroom building cost.
How a modular restroom project runs
Tell us the use
What happens inside the restroom, how many people or what equipment, where it sits and when you need it.
Layout and drawings
We return a layout and drawings with doors, windows, HVAC and electrical shown, plus a quote with exclusions listed.
Fabrication
After drawing approval, lead times are typically 4 to 8 weeks, subject to confirmation, for fabrication and freight.
Delivery and install
Panels or finished units arrive by truck and are assembled or set in place, then your trades make the final connections.
Your licensed plumber and electrician make the final connections to the building’s water, drain and power. Permits are usually required; check with your local building department, and we provide drawings for the submittal.
Modular restroom buildings for sale: how buying works
Our modular restroom buildings are built to order, not held as inventory, because fixture count, layout and utility locations differ on every site. We are an authorized dealer for a leading U.S. modular building manufacturer, so you work with one contact from layout through delivery.
Smaller restrooms can ship pre-assembled and be set in place; larger or indoor rooms usually ship as knock-down panels and are assembled where they will stand. Lead times are typically 4 to 8 weeks from approved drawings, subject to confirmation.
Where commercial modular restrooms are used
Modular restroom vs. portable toilets vs. restroom trailers
| Question | Modular restroom | Portable toilets | Restroom trailer |
|---|---|---|---|
| Connection | Plumbed to your water and drain lines | Self-contained, pumped out | Hoses to water and sewer, or holding tanks |
| Inside a building | Yes | Rarely suitable | No |
| Length of use | Long term, relocatable | Short term | Short to medium term |
| Comfort and finish | Commercial restroom finishes, HVAC and lighting | Basic | Varies by unit |
| Ongoing service | Normal cleaning | Regular pump-out service | Tank service if not connected |
For a crew that will be on site for years, a plumbed modular restroom usually costs less to live with than rented units, though every site should compare on its own quotes.
Combine the restroom with other rooms
A modular building can hold a restroom, a break room, a lactation room and an office under one roof, sharing walls and utilities. See modular break rooms and modular lactation rooms.
What to send us for a quote
- Headcount by shift and the split between men’s, women’s and single-user rooms.
- Location inside or outside, with photos.
- Distance to the nearest water, drain and electrical panel.
- Accessibility and any shower or locker needs.
- Timeline and any work windows.
How to choose the best modular restroom for your site
Count the users
Headcount per shift and per sex, plus visitors or drivers. This sets fixture counts under OSHA and your plumbing code.
Pick the location
Close to the work, near a drain and water line if possible, and out of forklift lanes or protected with bollards.
Choose the type
Indoor panelized room, exterior building, or a restroom combined with offices or change rooms.
Confirm utilities
Drain path, water heating, ventilation and an electrical feed, checked by your plumber and electrician.
Related guides: modular building permits and code compliance, the modular building buyer’s guide and the installation process. Back to the in-plant buildings hub.
Related project
A modular change room with lockers, ventilation and power, built under a storage mezzanine.
Stork, Salt Lake City: modular change roomA modular change room built under a storage mezzanine, with lockers, ventilation and power.Protect the Building: Bollards and Railing
Modular restrooms are quoted per project. Steel bollards and pipe safety railing that protect restroom walls and doors from forklift traffic can be ordered online.
Frequently asked questions
How much does a modular restroom building cost?
Can a modular restroom go inside a warehouse?
How many toilets do we need?
Are modular restrooms accessible?
Do you sell modular restroom buildings for outdoor sites?
Do modular restrooms need a permit?
Are modular restroom buildings for sale off the shelf?
Who manufactures your modular restrooms?
How many toilets does OSHA require?
What is the best modular restroom for an industrial site?
Can modular restrooms be delivered to Florida?
Plan a modular restroom
Send the headcount, the location and the distance to water and drain lines. We will return a layout, drawings and a quote.