Container Kings

Arguably the perfect example of sustainable construction and offsite methodology, the use of storage containers for building design has been one of the most intriguing developments in recent years. Gary Ramsay reports.

LIVING IN A BOX has never seemed so sexy. Or indeed having an office, artist's studio, youth centre or fashionable retail space seemed quite so hip. Much of this is due to the trailblazing use of one of the most commonly seen parts of industrial life - the ubiquitous storage container.

Taking the use of containers beyond storage and the site canteen has created a step change in architectural thinking and at the same time delivered the ultimate piece of offsite construction. Of course, they are nothing new and have been around for some time. There are many container developments in Australia, the USA and New Zealand in particular. In South Africa there have been a number of containerbased schools including the world's largest container based building; built in 1998 on the slopes of the Simonsberg Mountain in Cape Town, Simonstown High School Hostel, used 40 containers to house 120 boarders and is built on eleven different levels.

The components could not be easier to deal with. The sturdy stressed steel boxes come in a series of standard sizes - eight ft wide, eight ft high and in lengths of 10, 20 or 40ft and can withstand the knocks and bangs of being hauled all over the world as freight. However they are relatively light, weighing between 1.5 to 3.3 metric tonnes means they can easily be transported to just about anywhere. The steel used is corrosion resistant. so on average they only need a lick of paint every five to seven years. In addition, the containers can easily be raised on stilts above ground level making them particularly useful in areas that are under flood risk.

Access is important. A mobile-crane needs unobstructed access of around 30ft from the middle of the container to the middle of the vehicle for perfect manoeuvrability, and any overhead cable lower than 18ft is likely to get in the way and cause problems. One of the overriding plus points of container construction is the minimal foundation work. Because of their relative light weight they do not impose on the ground heavily. They can be safely placed on a lawn as long as the weight is distributed evenly over its footprint. Certainly for use on contaminated sites, the fact that the ground can remain virtually undisturbed and simply capped over, cuts huge decontamination and landfill costs as well save valuable build time.

LONDON LIVING Here in the UK, containers have been creating a stir since one of the first developments was built at Trinity Buoy Wharf in 2000 (basically 12 self contained studio workshops) Since then, the system has steadily grown to provide a variety of different building uses and could prove to be a perfect solution to the affordable housing and key worker accommodation crisis that continues to plague London and the South-East.

Not far from the entrance to the Blackwell Tunnel in East London, a three-storey office block is made entirely from recycled containers.

...... The series of containers have had circular windows cut into the ribbed skin to encourage large amounts of natural light to enter the units whilst retaining their structural integrity.

The container doors are strong enough to provide built-in balconies. These are supported by a steel frame with conventional patio doors fitted into the openings. The container's foundations consist of small 300mm deep concrete pads beneath the strengthened corner posts of each ground level container.....

...... Critics point to the angular Lego-like appearance, but effectively this is the way in which they pack an architectural punch. The container concept delivers an endless number of projects in any type of configuration. Also. the nature of the container flatness makes them perfect breeding grounds for the use of sedum and brown roof solutions making them havens for biodiversity.

"This modular technology provides both a green and affordable solution to Britain's housing crisis." says Eric Reynolds. Managing Director of Urban Space Management (USM), the pioneer behind Container City. "The system is a fast. inexpensive method of creating funky modern buildings in an environmentally friendly way. The base module is cheap adaptable, durable. transportable and reusable."

On a prepared site, costs are estimated to be around £650-£700 per sq m, minus design planning foundations and services - making them very cost effective. The interior is normally finished with a anti-condensation layer, then a layer of mineral wool is added before being dry-lined out with plasterboard.

Commercial containers come from a range of locations and are usually sourced from the many that have been 'retired' at Felixstowe, Liverpool, Southampton and Thamesport. Quality or quantity are not usually a problem. Containers are ISO certified for integrity on a regular basis but they do differ slightly between manufacturers - most are made in the Far East - so similar containers are used for each building depending on design requirements. As for numbers - it is estimated that approximately 300 million containers are in circulation around the globe at anyone time.

Also, proximity to container centres alters the price. In Scotland and Ireland - where there are smaller shipping volumes - the availability is smaller and the price of containers is higher. but on average, a used but useable 40 It unit costs around £1,000, a 20ft unit for a round £800.

As all regular readers will know onsite construction can be messy, wasteful, time consuming and costly. Offsite and prefabricated solutions go a long way in minimising these problems. Container structures - once the plan is designed - are prepared and fitted out in the workshop with time onsite as little as seven days to provide a fully weatherproof and watertight environment. The containers also offer a 100 per cent recycled solution - that's zero construction waste. Like I said, living in a box has never seemed so sexy - or so sensible.