Short answer: at CS Containers, Phil Cambridge quotes a container office conversion from around £6,000, depending on the spec. The plain containers they are built from start at £1,450 + VAT, and delivery anywhere in mainland UK is priced on your postcode. Size, insulation, windows, electrics and finish decide where you land.

Most suppliers will not put a number on a conversion because every build is different. That is true, and it is also no help when you are trying to work out whether this is a £6,000 project or a much bigger one. This guide shows what you are paying for, the prices we can stand behind, and which choices push the figure up. Updated October 2026.

What are you actually paying for?

A finished conversion is three costs. There is the container, the steel shell the room is built in, priced by size and grade. There is the build: insulation, lining, windows, doors, electrics and finish, all done in the workshop. And there is delivery, where a HIAB crane lorry brings it finished and lifts it into place, priced on your postcode and access.

Then a little is down to you: a level, firm base for it to sit on, an electrician to make the final connection, and planning permission if your project needs it.

How much is the container itself?

These are Phil's current prices for a plain container, before any conversion work:

Prices exclude delivery. Phil chooses the container to suit the build: a new one-trip box costs more but starts cleaner, which matters for a room people will sit in. The full list is on the shipping containers for sale page.

What does the conversion work cost?

There is no fixed price list, because every CS Containers conversion is built to the customer's spec and nothing sits finished in stock. What Phil does give is a starting point: a container office conversion from around £6,000, rising with the size and the specification.

A typical office or garden office build includes:

• Insulation to the walls, floor and roof, with anti-condensation measures
• Internal lining and a finished interior
• A personnel door and windows for light
• Power sockets and LED lighting, ready for the final connection on site

Which choices push the price up?

Each of these adds materials, workshop time or both:

• A bigger box. A 20ft or 40ft is more steel to insulate, line and wire than a 10ft.
• A new base rather than a used one, as the table above shows.
• Every window and door. Each one means cutting the steel, framing the opening and fitting the unit. See container doors and windows.
• More electrics: extra sockets, a heater or air conditioning.
• Water. A WC or sink means plumbing inside and a drainage connection on your site.
• The outside, whether that is timber or composite cladding or a respray in your colour.
• Partitions, if you want more than one room.

Phil will tell you which of these are worth it for what you plan to use the space for, and which you can leave out.

How much is delivery?

Delivery is priced on your postcode and how easy your site is to reach, so it is always a separate line on the quote. The lorry needs about 4 metres of clear width and around 3.5 metres of overhead clearance. Phil asks about gates, branches and soft ground before he quotes, so the price you are given is the price you pay. Container delivery explains how it works.

How do you get an exact price?

Tell Phil five things and he will come back with a written quote:

1. What the space is for (office, garden office, workshop, café, welfare unit)
2. The size you have in mind, or the room you have for it
3. Windows, doors, power and heating you want
4. How you want the outside to look
5. Your postcode and how the lorry gets in

Call Phil on 020 8226 0007 or send an enquiry. Payment confirms the order. Planning a garden office and still deciding between a container and a timber building? Read garden office pod or garden room, or see everything Phil builds on the container conversions page.