With human populations on the rise, providing suitable accommodation is no small task. While some cultures use modest building supplies, from sticks and mud or palm fronds, colder and more industrial societies require other options. Some communities have started to recycle building materials. But other imaginative concepts are also available.

While it might sound far-fetched, metal shipping containers may provide an alternative. In parts of the US, Asia, and Europe, these compartments have filled a need for temporary shelters. From natural disaster relief to homeless shelters, prefabricated metal boxes may be more than a stopgap solution.

Don’t imagine a windowless, featureless environment. Once a shipping container has reached the end of its useful cargo life, it is fair game for any modifications. Normally, these hulking steel structures would be left at the last port of call, with little chance of reuse or recycling. In the past decade or two, a few enterprising companies have been purchasing and creating with containers. Windows and doors can be cut into the sides, drywall and other materials are used to resurface inside walls, and the strength of steel supports any flooring - from concrete to hardwood.

While an unmodified container is a relatively quick and cheap housing option, elaborate changes will be more costly. Solar energy is one possible addition, along with green roofs, and anything else the imagination can picture. Given the many benefits of container housing - the recycled content, the lack of wood, the strength and stability - some builders suggest that containers would be a sensible alternative to trailers and other prefabricated homes. Certainly, the solid steel structures are not so easily destroyed, yet offer affordability and rapid construction.

At eight feet by 40 feet, one container can provide emergency space for one person. Stacked, they can take on many configurations - from storage facility to hospital, even a youth hostel or sauna. Architects and builders who work with containers find the modular shape ideal for a huge variety of projects. London has a wide set of these modular buildings, including several Container City sites, a school extension, a children's centre, and even some music studios.

Even with new containers intended for cargo use, companies have been examining more environmentally friendly paths. Maersk is increasingly using bamboo and recycled wood flooring. Given modern society's propensity for global transportation of many items, it is unlikely that the container supply will run out soon (not to mention the many dormant containers worldwide), making it a relatively sustainable building option.