How to specify an office container: a buyer's checklist

A site office gets used harder than most permanent offices. Doors slam thirty times a day, the heating runs unattended, and the unit is craned, trucked and re-sited several times over its life. Most disappointments we hear about trace back to one moment: the order was placed from a one-line description, "office container, 20 ft, white", and everything else was left to assumption.

This checklist walks through what a buyer should fix in writing before ordering, in the order a production hall actually needs the answers. It applies whether you buy from us or from anyone else.

What size is an office container, really?

The standard office and living container measures 6058 x 2438 x 2800 mm externally. That external height matters more than buyers expect: after floor build-up and ceiling, the internal clear height lands around 2500 mm, which is the difference between an office and a corridor with desks.

Check three dimensions in the quotation, not one: external footprint (does it fit the site plot and the truck), internal clear height (comfort and regulation), and door and window openings (can your furniture and people actually move through them). If a supplier quotes only "20 ft equivalent", ask for the millimetres. A fabrication drawing exists for every real unit; a manufacturer can send it within a day.

• External: 6058 x 2438 x 2800 mm is the reference for a single office module.
• Internal clear height: roughly 2500 mm after floor and ceiling build-up.
• Stacking: if a second floor is ever possible, say so now. Corner castings and frame grade are a build-time decision, not a retrofit.

Which insulation should you specify?

For year-round office use in Central and Northern Europe, PIR sandwich panels are the default answer. PIR gives more thermal resistance per centimetre than mineral wool, so walls stay thin and the interior stays usable. Mineral wool earns its place where acoustic damping or specific fire behaviour drives the spec.

Ask the supplier to state the panel type and thickness for walls, roof and floor separately. The roof always needs more than the walls. As a reference point from leisure-sector units we have delivered: 100 mm walls, 140 mm roof and 100 mm floor in mineral wool kept seasonal staff accommodation comfortable through mountain winters. A PIR build reaches similar comfort with thinner panels.

One question exposes a trader instantly: "what is the panel thickness in the roof?" A manufacturer answers from the drawing. A reseller has to go and ask.

What about heating, cooling and electrics?

An office container is an electrical installation, and it should be wired to a recognised low-voltage standard with a documented distribution board, not a row of extension leads. Specify in writing: heating type and rating (electric panel heating is the simple default), air-conditioning if summer use is real (around 2.6 kW of cooling per module is a workable reference for occupied units), the number of socket circuits, lighting type, and IT preparation (conduit and cut-outs cost almost nothing at build time and a weekend of frustration later).

Have the quotation name the electrical norm the installation is built to and include the test protocol on handover. If the unit will cross borders, multilingual documentation saves real time during inspection.

What separates a manufacturer from a trader?

A trader sells you a box that exists; a manufacturer builds the box you specified. Both have a place, but you should know which one you are talking to, because it changes what questions get real answers.

Three checks that take five minutes:

• Ask where the welding happens and to which standard. A production line answers with a norm (ours is audited under ISO 3834-2, feeding an EN 1090 EXC2 steel line) and a place (for us, one hall in Bánovce nad Bebravou, Slovakia).
• Ask for a shop drawing of the unit you are buying. Manufacturers produce one before any steel is cut; the customer signs it off, and that signature gates production.
• Ask what happens before paint. Surface preparation to Sa 2.5 by blasting, then painting and curing in a controlled booth at 75 to 80 degrees C, is what makes a coating last a decade outdoors. "It gets painted" is not an answer.

How should delivery and lead time be agreed?

Fix the Incoterm, not just the date. EXW means you collect at the factory gate and own the transport risk; DAP means the manufacturer delivers to your site. Both are normal, but the price difference is real and the responsibility line must be in writing.

For lead times, a catalog office unit typically runs 6 to 10 weeks from order; custom builds run 10 to 16 weeks. Treat any quotation that promises a custom unit in a fortnight with suspicion: either the unit already exists (so ask what was changed for you, and check it against your spec), or the promise will quietly slip.

A fixed quotation should hold its price and its lead time. Ours typically arrive within 3 to 5 working days for standard families, and the lead time printed on them is the one production plans around.

FAQ

What does an office container cost?

Serious suppliers quote per specification rather than from a public price list, because insulation, electrics, climate and delivery terms move the number significantly. Expect a fixed, itemised quotation within a few working days of sending your requirements; treat any price quoted before the specification is known as provisional.

Can office containers be stacked into two floors?

Yes, with the right frame and corner castings, double-stacked layouts are routine. The decision must be made before fabrication: stacking loads are carried in the steel frame, which cannot be meaningfully upgraded after the unit is built.

How long does an office container last?

A properly fabricated and painted unit (blasted to Sa 2.5, paint cured in a booth) is a 15 to 20 year asset outdoors with normal maintenance. The coating system and the quality of the welds, not the panel brand, set the lifespan.

What documents should arrive with the unit?

At minimum: the fabrication drawing as built, the electrical test protocol, care and maintenance instructions, and transport documents (CMR for road delivery). For units intended for international intermodal transport, a CSC plate and its paperwork.

The takeaway

Write the specification down before you ask for prices: external and internal dimensions, panel type and thickness per surface, heating and cooling ratings, electrical norm and circuits, Incoterm, and the documents you expect at handover. Ten lines of text protect a five-figure purchase.

If you want a worked example, the Office & Living family page shows the reference configuration, and the guide to lead time expectations explains what happens between order and delivery. When your list is ready, request a quotation and we will return a fixed price and lead time, typically within 3 to 5 working days.