Prefab sprouts

Prefabricated steel structures could be the way forward for residential development in a world of scarce resources and increasing energy costs

If asked which materials you associate with a healthy environment, steel may not be the first answer that springs to mind. “People remember the bad old days when smoke belched out of the top of steel mills,” says Lucien Weber, of the technical advisory of steel producer Arcelor-Mittal. But he insists that the manufacturing of steel is actually extremely clean: “Now, modern and efficient electric filters are installed so that the smoke pollution and emission of particles has been reduced to almost zero. The negative image of steel has absolutely no foundation in today’s manufacturing practices,’ he explains.

Up and down

According to Mr Weber, the most important environmental advantage of steel lies in its potential for being reused and recycled. And this is especially true in the construction of buildings, and is a feature which distinguishes it from other more traditional building materials, such as concrete, brick or wood. “One of the strong ecological aspects of using steel in construction is the possibility to reuse the sections after the end of lifetime of the building. Here, the steel building can either be dismantled and reconstructed at a different location or the individual steel elements can be reused for the construction of a new structure. In case there is no longer any scope for the reuse of the steel elements, it is possible to recycle it. The scrap is then used as the base material for producing high quality structural and offshore steels. This is what we call the ‘upcycling of scrap’ – as opposed to the ‘down-cycling’ of other building materials which can only be recycled in inferior applications.”

According to Arcelor-Mittal’s specialist, almost 100 pct of the steel used in a building’s construction can be recycled (with the exception of the material used in the foundations). Other sources of scrap which can be recycled are from manufacturing processes, or – for example – from old washing machines and car bodies. Mr Weber adds to this the fact that 95 pct of the beams produced worldwide by Arcelor-Mittal are recycled, whereas the overall average in the industry is for 50 pct to be steel is recycled. “Over the next few years, efforts must be made by everybody participating in steel production and construction industry to increase the percentage of recycled scrap,” argues Mr Weber.

Potential new market

Joost Heijnis, of the Dutch-based Architectenbureau Cepezed studio, is currently working on the realization of the Kick Start project in Warsaw, after the design submitted by the Architectenbureau Cepezed studio won the Living Steel competition last year. This competition is organized by the International Iron and Steel Institute, an association set up by leading steel producers to promote the idea of using pre-fabricated steel in housing design and construction. This would be the first such project in Poland and the intention is to introduce the concept and thus open up a new market. Lucien Weber of Arcelor-Mittal is of the opinion that this method of construction not only brings with it environmental benefits, but financial ones too: “This prefabrication also saves a lot of construction time. So there is an earlier return on the investment for the developer, which is a big economic advantage for steel structures,” asserts Mr Weber.

Flexible steel

In addition to the reusability and recyclability of steel, another advantage is the flexibility of the material, in terms of its potential for adapting buildings for different uses. “Nowadays, a lot of buildings are being renovated” explains Mr Weber. “It is easy to keep the old structure of a building and give it a new facade, or alternatively keep the old facade and put a new steel structure inside. In specific cases, the size of a building can be increased by adding 1-2 floors with a steel structure at the top.”

Although in Poland the use of steel in office and other non-residential buildings may now be familiar, getting people used to the idea of steel residences may prove to be a trickier proposition. More natural materials – such as clay brick or wood – or more conventional ones such as concrete, are still those which are most identified with housing design and construction.

“Using natural materials is always more healthy,” claims Maciej Miłobędzki, an architect and partner of the Warsaw-based JEMS Architekci studio. In his opinion, it is difficult to compare the environmental advantages of the different materials. However, he adds that: “It is difficult to buy bricks made from clay, and not so many of these natural materials are coming on to the market. And as it is still such a small market they are expensive.”

In 1999 JEMS Architekciwon a contest to design a steel-structured wooden-panelled house out of pre-fabricated elements – “the House of the Future”. This was eventually built in 2002 in the Warsaw suburbs for a private client.

Kick starting
Kick Start

Unlike the House of the Future, the Kick Start project has yet to get off the ground, having yet to receive the necessary fire safety approval. Joost Heijnis believes this is down the fact that professionals working in both public administration and the private sector are unfamiliar with the concept of prefabricated steel dwellings. “It is very much a process of educating people,” says Mr Heijnis. “Everytime we come to Poland we have to explain how the concept works – how energy-efficient the construction process and the buildings are, the fact that fewer materials are necessary – but slowly we are making progress.”

Mr Heijnis is also of the opinion that current fire and safety regulations more or less restrict the design possibilities of such buildings.

Changing their ways

Maciej Miłobędzki of JEMS believes that for the use of energy-efficient materials to really take off in Poland, some new legislation will be needed: “The role that the state plays is all important. If there are regulations that energy efficient materials should be used, then this would force builders and architects to change their methods. Tax incentives are another option – but there is nothing like this in Poland at the moment. So for developers and clients there are no advantages at present in using such materials.”

With prices for both raw materials and energy increasing, schemes such as Kick Start may be the first step towards a necessary change in the culture of residential design and construction in this country.    n

Nathan North