Buying a Used Container? What to Check First: Steel Shipping Containers vs Used Office Units

In Thailand, the term used container is used for two very different things. The first is a steel shipping container retired from freight service and resold as an empty box. The second is a used office unit or knock-down house — a ready-to-use room that has already been in service. Both are called "containers", but the price, the work still needed and the way you can use them are completely different.

This article draws on more than 25 years of working with both types, so you know what you are actually buying, where to look, and when you may not need to buy at all. To be clear from the start: Container To Build does not sell empty steel shipping containers. We rent out 20 ft steel containers for storage, and we sell used office units, toilet units and accommodation units that we manufacture ourselves. So if you have already decided to buy an empty steel container, this article will still help you choose more carefully.

What can "used container" mean?

Type 1 — Used steel shipping containers

These are corrugated steel boxes, 20 ft or 40 ft, that once carried goods on ships and trucks. When their life in the freight system ends, they are sold as-is. The box is all steel, with two steel doors at the end, no windows, no insulation and no electrical system. The advantages are that they are strong, keep water out well and are easy to find. They suit storing goods that are not sensitive to heat. To use one as a workspace or shop, you have to cut openings, drill, insulate and run all the wiring yourself.

Type 2 — Used knock-down office units, toilet units and accommodation

These are prefabricated rooms that have already been used. Thai people commonly call them containers too, but Container To Build's units of this kind are not cut-down shipping containers. They are units built in the factory from the start: a steel frame with walls and roof of insulated sandwich panels, complete with door, windows and electrical system. Lift them onto site, connect the power and they are ready to use. The "used" part means they have been out on rental jobs and come back.

If you are buying a used steel shipping container — 7 things to check in person

No two used steel containers are alike, so the price tells you less than standing in front of the container. Before you transfer any money, walk through these checks.

1. Container grade — Used containers are roughly graded as "as-is" (sold as seen, may have dents and rust), "repaired and repainted", and "one-trip" (shipped only once, near-new condition). Prices vary a lot. Ask clearly which grade the unit you are discussing is.
2. Rust-through — The usual weak spots are the four bottom corners, the floor cross-members and the roof. The easiest test is to stand inside, close the doors and see where light comes through.
3. Floor — Shipping container floors are thick plywood. Walk over the whole floor; any spot that sags or gives way is rotten wood, and replacing it is not a small cost.
4. Doors and door seals — Open and close both doors fully. Every locking bar must lock. Door gaskets that are hard, brittle or torn will let water in.
5. Twisted frame — A container that has been dropped or crushed will have doors that do not close properly. If you have to push the doors unusually hard, suspect a twisted frame. This is the hardest of all the issues to repair.
6. What it used to carry — Ask about its history. Containers that carried chemicals can have smells and stains that are hard to remove, and are not suitable for storing food or for use as a room.
7. Site access — A 20 ft container is about 6 metres long and fits on a 4-ton truck with a 7-metre bed. A 40 ft container is about 12 metres long and needs a trailer truck, plus space for the truck to turn and park for lifting. If the truck cannot get in, the container cannot be set down. Read more in Container sizes: what types are there, and how to choose one a truck can deliver to your site

The "used container price" you see is not what you will actually pay

Most listed prices are for an empty container, collected by you from the yard. The real cost of getting it ready to use has to include the following.

• Transport to site, charged by distance and truck type
• A crane or truck-mounted crane to lift the container down
• A base to sit on — at minimum, pads under all four corners on compacted ground. See how to prepare it in our guide to preparing the ground before installing a unit
• If it will be used as a room: cutting door and window openings, reinforcing the frame where it is cut, insulation, ceiling, a new floor, electrics, air-conditioning and painting

Prices for empty containers on the market range from tens of thousands to hundreds of thousands of baht, depending on grade, size and whether they have been repaired. What we recommend is to compare the "total cost until usable", not the container price. The lowest-priced empty container can turn into the most expensive room once you add floor repairs, new doors and insulating the whole box.

If you are buying a used office unit — what to check first

With a used office unit you do not need to look for rust-through or a plywood floor as with a shipping container, but there are different points to check.

• Service history — Where did it come from and how many years has it been used? Most of our used units are retired from rental work early, mostly within 5 years. The unit itself has a service life of 10 years or more, and the main structure lasts 20 years or more with scheduled maintenance, such as replacing the silicone sealant roughly every 10 years.
• Lower steel frame and base — This is where water hits most. Bend down and look along the bottom edge all round and underneath the unit.
• Wall panels — Look for swelling, delamination and the joints between panels.
• Electrical system — Ask to switch on the lights, plug something in and run the air-con before you accept the unit.
• Where it was stored before sale — Units left out in sun and rain waiting to be sold deteriorate faster than units stored indoors. Every used unit of ours is kept in an indoor showroom. The condition you see today is the condition you will receive, and every unit is inspected and serviced before it is put up for sale.

Prices at the time of writing (September 2569 (2026)), to give you an idea: a used WH office unit, 3×6×2.69 m, with electrical system, is around 97,500–99,900 THB (5,420 THB/m²+); with a built-in toilet, 129,000 THB (7,170 THB/m²); a used K-TYPE toilet unit, 0.83×1.08 m, 11,900–12,500 THB (13,220 THB/m²+); and used accommodation, 119,000 THB. Stock changes all the time — see the current list at all second-hand products

If you only need storage for a while — you don't have to buy

Many people searching for a used container actually need temporary on-site storage — during construction, while moving a shop, or when stock overflows. In those cases buying a container leaves you with a burden later, both reselling it and paying for a truck to take it away.

We offer used 20 ft steel containers for monthly rental at 3,500–4,000 baht per month depending on the rental period. Every container is inspected and any rust-through is repaired before delivery. We deliver with our own trucks, charge transport by distance and always quote the price first. You use your own padlock, and when the job is finished you just let us know and we come and collect the container.

Summary: choose by the job, not by the container price

Whichever option you choose, please see the real thing before you decide. All our used units can be viewed at both showrooms, Suwinthawong and Bangna.

Frequently asked questions

See the real thing before you decide

All used office units and toilet units can be viewed at the showroom. Call 098-264-5529 or send us a message telling us what you will use it for, the size of the area and the site access, and our team will recommend the option that suits your job.

See all second-hand products Rent a 20 ft steel container