17 units per 40HQ: the logistics number that decides relief housing cost

In a relief operation, freight is usually the line item nobody budgeted properly. The reason is simple: buyers compare unit price, not landed cost. And landed cost depends almost entirely on how many units fit in a container.

Folded volume is everything

A six-metre module with a steel frame, closed for transport, occupies a fraction of the volume it occupies once installed. That package sets the loading ratio:

Loading ratio for a 6,000 × 3,000 mm module. The figure falls if units ship with electrics and flooring already fitted, because both take volume inside the package.

The practical consequence is direct: at 17 units per 40HQ, a 200-home settlement moves in 12 containers, not 200. Ocean freight per unit is divided by seventeen, and that is the number that changes the cost structure of a programme.

Folding is not dismantling

Two families get confused in tenders, so keep them apart:

• Folding container house: side walls fold against the frame and the roof drops. It opens on site with hand tools and can be closed again for relocation.
• Flat pack container house: arrives as a panel and frame kit, assembled on site with bolts. Allows even more compact packages, at the cost of more assembly hours.

Both are prefabricated houses in the technical sense, but the second needs an assembly crew and the first does not. For a programme that must commission housing within 72 hours, the difference matters.

Closed package before loading. Loading ratio is calculated on this volume, not on the installed unit.

What can and cannot be pre-fitted

• Electrics: factory-fitted saves days on site but reduces units per container.
• Vinyl flooring: fitted improves the finish and removes site work; rolled and shipped separately takes less volume.
• Bathroom and kitchen: a pre-assembled wet pod commissions faster but adds bulk.

The usual recommendation for emergency response is to ship the first wave with electrics and flooring fitted so units enter service the same day, and later waves in dry specification to maximise units per container.

Port, road and the last mile

The container solves the ocean leg, not the last kilometre. A six-metre folding module needs a lorry with a crane or a small mobile crane to come off the container and sit on its supports. On sites with difficult access, plan pre-cast concrete point supports instead of a slab: they travel on the same lorry and need no curing.

That detail usually decides whether a unit is habitable on the day it arrives or three weeks later.