Quick Answer: Office Trailer Sizes
Standard office trailer sizes run from an 8×20 (160 sq ft) for one or two people to a 24×60 double-wide (1,440 sq ft) for 10 to 15. The 8×36, 10×40 and 12×60 single-wides sit in between. Monthly rent runs about $200–$450 for an 8×20 and $800–$1,800 for a 24×60. Nominal sizes often include the hitch, so ask for the box dimensions before you plan the site. Units wider than the federal 102-inch limit generally move on state oversize permits.
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Office Trailer Sizes: Dimensions, Layouts and Capacity
Picking between office trailer sizes looks simple until the unit arrives. Too small, and plan reviews happen on the tailgate. Too big, and you pay every month for floor space nobody uses, on a site where every square foot of ground already has a job. Both mistakes cost money.
This guide is for contractors, facility managers and business owners who need a temporary or relocatable office and want to get the size right the first time. It covers the common mobile office trailer sizes and what each one holds. You will also see how nominal size differs from real dimensions, what width means for delivery, and how to match a unit to your team.
Office Trailer Sizes at a Glance: The Size Chart
Start here. The chart lists the office trailer sizes you will see on most quotes, with floor area, a realistic headcount and the rooms each one usually holds. Sizes are nominal width by length in feet, so square footage is simply one times the other.
| Nominal Size | Square Feet | Typical Capacity | Typical Rooms | Common Uses |
|---|---|---|---|---|
| 8×20 single-wide | 160 | 1–2 people | One open room | Superintendent office, security checkpoint, gate office |
| 8×36 single-wide | 288 | 2–4 people | Open room, sometimes a small private office | Small contractor office, plan review space |
| 10×40 single-wide | 400 | 3–5 people | Open area plus one private office | Mid-size project office, admin space |
| 12×60 single-wide | 720 | 5–8 people | One or two private offices, open area, meeting space, optional restroom | General contractor office, team space |
| 24×60 double-wide | 1,440 | 10–15 people | Several private offices, conference room, restrooms, break area | Project headquarters, multi-department office |
| Other lengths (such as 10×50) | Width × length | Between the neighbouring sizes | Varies by floor plan | When a standard length is just short |
Capacity assumes desks, filing, a place to unroll drawings and room to walk past a seated coworker. A layout with private offices or a restroom holds fewer people than an open room of the same size. Treat the low end of each range as comfortable and the high end as full. That rule holds across all office trailer sizes.
Small Office Trailer Sizes: 8×20 and 8×36
The two smallest office trailer sizes share one width. An 8-foot-wide unit is the easiest to deliver and the cheapest to rent. The trade-off is the width. Once you add a desk along one wall, the remaining aisle is narrow, and two people cannot work side by side without bumping chairs.
8×20 Office Trailer
160 square feet, 1–2 people
The small office trailer most sites start with. A typical layout puts one desk at the far end, a file cabinet and a plan rack along the wall, and the door near the other end. It works for one supervisor, a security checkpoint or a gate office. A second regular occupant makes it tight, and a meeting of three is standing room only.
Price line: rent runs about $200–$450 a month; new units sell for about $15,000–$22,000 and used ones for about $5,000–$14,000.
8×36 Office Trailer
288 square feet, 2–4 people
Almost twice the floor of an 8×20 at the same width. The usual plan places a workstation at each end with a small table in the middle, or partitions one end into a private office. Because the width does not change, it still reads as a long corridor. It suits a small contractor team or a plan review office where people mostly work at their own desks.
Price line: rent runs about $300–$550 a month; purchase prices fall between the 8×20 and the 10×40.
Mid-Size Units: 10×40 and 12×60 Dimensions
Width changes everything inside a trailer. At 10 or 12 feet, desks can face the wall with a real aisle behind them. A partitioned office starts to feel like a room instead of a closet. These are the construction trailer sizes most project teams end up choosing.
10×40 Office Trailer
400 square feet, 3–5 people
A good fit for a small project team that needs desks and a place to spread out drawings. Two layouts are common. An open plan lines workstations along both walls with a plan table at one end. The other partitions a private office at one end for the project manager, leaving open space for the rest of the team.
Price line: rent runs about $350–$650 a month; new units sell for about $25,000–$40,000 and used ones for about $12,000–$25,000.
12×60 Office Trailer
720 square feet, 5–8 people
The workhorse. A 12×60 usually holds one or two private offices, an open work area and a small meeting space, and many floor plans add a restroom. It is where general contractors often land once the team includes a project manager, an assistant and regular subcontractor meetings. Choose it over a 10×40 when meetings happen inside rather than at the tailgate.
Price line: rent runs about $450–$900 a month; new units sell for about $35,000–$55,000 and used ones for about $18,000–$38,000.
In-between lengths such as a 10×50 exist too. Their capacity and price fall between the neighbouring sizes, and rent is quoted by size, term and market. Ask for the floor plan rather than guessing from the length.
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Get Free Quotes →Double Wide Office Trailer: 24×60 and Multi-Unit Setups
A double wide office trailer is two single-wide sections built to be joined. Each half travels on its own load, and on site the crew sets them side by side and closes up the seam along the center wall. The crew finishes the seam inside. The result is a 24-foot-wide interior that feels like a small office building. It is the largest of the standard office trailer sizes. Our double wide office trailer guide covers floor plans, joining the halves on site and cost in more detail.
24×60 Double-Wide Office Trailer
1,440 square feet, 10–15 people
The size to consider once the team passes seven or eight people, or once you need a real conference room. Floor plans commonly include a reception area, several private offices, a conference room, a break area and restrooms. Because there is a center hallway, private offices can open off both sides.
Price line: rent runs about $800–$1,800 a month; new units sell for about $55,000–$75,000 or more, and used ones for about $25,000–$50,000.
What a Double-Wide Gives You
- A conference room that seats the whole team
- Private offices off a center hallway
- Room for restrooms without losing workspace
- A layout that feels like a permanent office
What a Double-Wide Costs You
- Two transport loads instead of one
- More delivery and setup cost to join the halves
- A larger level pad and more site space
- A longer wait from order to move-in
Double-wides cost more to deliver and set than a single-wide, because two halves arrive and get joined on site. Past 15 people, many sites link several single-wides instead. A multi-unit complex usually covers 2,000 square feet or more and rents for about $1,500–$4,000 or more a month. Our guide to construction site office trailers covers how those complexes are laid out and connected.
Office Trailer Dimensions: Nominal Size vs. the Real Box
Here is the part that catches buyers. Office trailer sizes on a listing are nominal sizes. A nominal size often includes the hitch, so a unit called a 12×60 may have a shorter box than the name suggests.
Always ask the supplier for three sets of office trailer dimensions before you commit:
- Box dimensions: the outside length and width of the building itself, without the hitch
- Overall transport dimensions: length with the hitch, width including trim or eaves, and height on the chassis
- Interior dimensions and ceiling height: walls take space on each side, and ceiling height varies by model
Get it in writing. Ask for a floor plan drawing with window and door locations too. Two trailers with the same nominal size can have very different usable walls. A door in the middle of a long wall splits the room in two, which is fine for an office at each end and awkward for one open workspace.
💡 Measure Your Ground, Not Just the Trailer
Whatever office trailer sizes you are comparing, mark the box dimensions on the ground where the unit will sit, then add room for steps or a ramp at each door. Stairs and landings stick out from the trailer, and a ramp needs far more length than a set of steps. This is where many sites discover the spot they picked is too tight.
Transport Width, Permits and Site Access
Width decides how a trailer travels. When you compare office trailer sizes, width is the number the delivery crew cares about most. On the National Network of highways, the Federal Highway Administration says no state may impose a width limitation of more or less than 102 inches. That is 8 feet 6 inches. Units wider than that generally move under state oversize permits, and the rules, escorts and travel hours depend on the state and the route.
| Nominal Width | In Inches | Against the 102-Inch Limit | What to Expect |
|---|---|---|---|
| 8 ft (8×20, 8×36) | 96 | Under, before trim | Confirm the overall width with trim and eaves |
| 10 ft (10×40) | 120 | Over | State oversize permit, route set by the state |
| 12 ft (12×60) | 144 | Over | State oversize permit, route set by the state |
| 24 ft double-wide | 144 per half | Over, for each half | Two oversize loads, joined on site |
Suppliers often arrange the transport permits. Ask whether they are in the delivery price. Then look at your own site. Walk it yourself. Check the gate width, the turn off the road, overhead wires and tree limbs, and whether the ground will carry a loaded truck after rain.
Many office trailers are commercial modular units, and the rules for building and placing them sit with state modular programs and your local building department. The International Code Council's ICC/MBI off-site construction standards set requirements for designers, manufacturers, transporters and assemblers. Ask your building department what it needs to see before the unit is occupied.
Layouts: Restrooms, Private Offices and Open Space
Floor area tells you how much fits. The layout tells you how many people can actually work. Layout matters as much as the choice between office trailer sizes. Three decisions shape the plan inside most mobile office trailer sizes.
Private offices. Every partition eats open floor. Count who truly needs a door. A project manager taking calls with owners often does. An estimator reading drawings usually does not. In a 10×40, one private office is the practical limit.
A restroom. An inside restroom is convenient, but it takes floor space and needs water and a waste connection or holding tank. On construction sites, OSHA's sanitation standard 29 CFR 1926.51 requires at least one toilet for 20 or fewer employees. Where there is no sanitary sewer, it allows chemical toilets unless local codes prohibit them, so a trailer restroom is not the only way to comply. Our guide to the office trailer with bathroom covers which sizes carry one, sewer versus holding tank, and cost.
Meeting space. Decide whether weekly coordination meetings happen inside. If they do, the trailer needs a table that seats everyone, which often pushes a team from a 10×40 to a 12×60.
⚠️ Public-Facing Offices Need Accessible Space
The ADA lists office buildings as commercial facilities, and ADA Title III says businesses that build or alter facilities must follow the ADA Standards for Accessible Design. If clients, applicants or the public will visit, ask your building department what applies to your trailer. An accessible ramp and restroom take floor and ground space, so plan them into the size decision.
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Compare Free Quotes →How to Choose the Right Construction Trailer Size
Comparing office trailer sizes starts with people, not square feet. Size for your busiest month, not your first week. A project team grows as work ramps up, and swapping a trailer mid-project means a second delivery and a second setup. Work through these questions in order.
| If Your Situation Is… | Start With | Why |
|---|---|---|
| One supervisor or a gate office | 8×20 | Smallest footprint and easiest delivery |
| Two to four people at their own desks | 8×36 or 10×40 | The 10-foot width makes a far better layout |
| A team of five to eight with regular meetings | 12×60 | Room for private offices, a meeting table and a restroom |
| Ten or more people, or a conference room | 24×60 double-wide | A center hallway with offices on both sides |
| Several departments or 15+ people | Multi-unit complex | Units can be added or removed as the project changes |
Next, check the site. Bigger office trailer sizes need bigger pads. Measure the spot, walk the delivery route and confirm where power will come from. A 12×60 that cannot reach its pad is worse than a 10×40 that can. Ground space is not negotiable.
Then settle rent or buy. Short projects usually rent, and our office trailer rental guide covers monthly rates, delivery fees and lease terms. If you will use the unit for years or across several sites, the guide to office trailers for sale covers new and used prices and how to inspect a unit. A construction office trailer also needs power, internet and a safe spot on the site, which that guide explains.
Still between sizes? Go one size up if meetings happen inside. Go one size down if the team spends most of the day in the field. When the need stretches past a few years, a portable office building may be worth pricing alongside a trailer.
Frequently Asked Questions
What are the standard office trailer sizes?
The common office trailer sizes are 8×20 (160 sq ft), 8×36 (288 sq ft), 10×40 (400 sq ft), 12×60 (720 sq ft) and the 24×60 double-wide (1,440 sq ft). Suppliers also offer in-between lengths such as 10×50, whose area is simply width times length.
How many people fit in different office trailer sizes?
As a planning guide for office trailer sizes, an 8×20 fits 1–2 people, an 8×36 fits 2–4, a 10×40 fits 3–5, a 12×60 fits 5–8 and a 24×60 double-wide fits 10–15. Private offices and a restroom lower those numbers, while an open room holds more.
What is the difference between a single wide and a double wide office trailer?
A single wide office trailer is one section, usually 8, 10 or 12 feet wide, delivered as one load. A double-wide is two sections set side by side and joined on site, giving a 24-foot-wide interior with room for a conference room and several private offices.
Do listed office trailer sizes include the hitch?
Often, yes. Nominal office trailer sizes frequently include the hitch, so the box itself can be shorter than the name suggests. Ask the supplier for box dimensions, overall transport dimensions and interior dimensions before you plan the site.
How wide can an office trailer be before it needs an oversize permit?
On the National Network of highways, the federal width limit is 102 inches, or 8 feet 6 inches. Units wider than that, including 10-foot and 12-foot trailers, generally travel under state oversize permits. Rules and routes vary by state.
What size office trailer do I need for a construction site?
Size for the busiest point of the project. A single supervisor fits an 8×20, a small team fits a 10×40, and a team of five to eight with regular meetings usually needs a 12×60. Larger teams move to a 24×60 double-wide or a multi-unit complex.
What is a small office trailer used for?
A small office trailer, usually an 8×20 or 8×36, works as a superintendent's office, security checkpoint, gate office or plan review space. It is the easiest size to deliver and place, but it gets tight beyond two to four people.
How much do different office trailer sizes cost?
Across office trailer sizes, monthly rent runs about $200–$450 for an 8×20, $300–$550 for an 8×36, $350–$650 for a 10×40, $450–$900 for a 12×60 and $800–$1,800 for a 24×60. New units sell for about $15,000–$22,000 for an 8×20 up to $55,000–$75,000 or more for a 24×60.
Can office trailers be joined together?
Yes. Beyond the 24×60 double-wide, many large sites link several single-wide units into a multi-unit complex, usually 2,000 square feet or more. Units can be added or removed as the project grows or winds down.
Getting the Size Right
The right choice among office trailer sizes comes from three numbers: peak headcount, the rooms you need and the space on your site. Get those on paper first. Then ask every supplier for box dimensions and a floor plan, so you compare real trailers rather than names.
Most teams land on a 10×40 or a 12×60. Larger groups move to a double-wide. Whichever you pick, confirm the delivery width and route before the order is signed. With that done, the trailer that shows up will fit the team and the site.
Browse every guide in our mobile office category for more on pricing and setup.
Related Resources
- Office Trailer Rental: Monthly Costs and Lease Terms
- Office Trailers for Sale: New and Used Buyer's Guide
- Construction Office Trailer Guide: Setup, Safety and Cost
- Portable Office Buildings: Cost and Options
- Modular Office Building Cost Guide
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