A 20ft office container gives you a private, secure workspace without the cost and delay of a traditional building. Site managers use them as cabins, small businesses use them as extra office space, and more and more people are turning them into garden offices. If you are looking for a 20ft office container for sale, this guide explains your options, what a good conversion includes and what to plan for.
Why Use a Container as an Office?
- Fast: a container can be delivered and in use within days, not months.
- Secure: a steel shell with lockable doors is far harder to break into than a timber cabin.
- Durable: built to survive ocean crossings, containers stand up well to the British weather.
- Portable: when a project ends or you move premises, the office can be lifted onto a lorry and taken with you.
- Good value: compared with a permanent extension or portable building, a container is usually the cheaper route to a usable room.
How Much Space Does a 20ft Office Container Give You?
Inside, a 20ft container measures roughly 5.9m long by 2.35m wide, giving about 13.9m² of floor area. After insulation and wall linings you can expect to lose around 100mm from each wall. That is enough for two or three desks, a small meeting table, or a desk area plus a separate storage or welfare space at one end.
We strongly recommend a High Cube container for any office use. The extra 300mm of height means you still have comfortable headroom after the floor, ceiling and insulation are fitted. Our 20ft High Cube container is a popular starting point.
Your Options
1. Start with a workshop container
Our 20ft workshop container already has openings and a layout designed for working inside rather than storage, which gives you a head start on an office fit-out.
2. Convert a standard or one-trip container
Buy a plain container and have it fitted out to your own specification. A one-trip container is the best base for this because the walls are straight and the floor is clean. Read our one-trip vs used guide for why condition matters for conversions.
3. Choose a unit with windows or side access
A container with side opening, such as our 20ft High Cube container with side opening, lets in far more light and can suit a showroom, sales office or kiosk.
What a Good Office Conversion Includes
- Insulation in the walls, roof and ideally the floor. This is the single most important step, because an uninsulated steel box is cold in winter, hot in summer and prone to condensation.
- Wall and ceiling linings, typically plywood or plasterboard, to give a finished interior.
- Windows and a personnel door, so you do not need to open the heavy cargo doors every day.
- Electrics including lighting, sockets and a consumer unit, installed and certified by a qualified electrician.
- Heating and ventilation, such as an electric panel heater or air conditioning unit and trickle vents.
- Flooring, usually vinyl or carpet tiles laid over the existing container floor.
Planning and Building Regulations
A temporary site office on a construction project often falls under permitted development for the duration of the works. A permanent office in a garden or on business premises is more likely to need planning permission, and any electrical work must meet UK wiring regulations. If people will work in it regularly, building regulations for insulation and ventilation may also apply. Check with your local council early on so there are no surprises.
Site Preparation
An office container should sit on a firm, level base such as concrete pads or a compacted hardcore bed, raised slightly to allow airflow and drainage. Think about where power and internet will come from, and make sure the delivery lorry can reach the spot. Our delivery and site access page has more detail.
Find Your 20ft Office Container
We supply 20ft containers suitable for office use, including High Cube, side-opening and workshop units, direct from our Essex yard with delivery across the UK. Browse the shop, read our complete 20ft container guide, or contact us to talk through your plans.