Ecological and environmental influences

Many architects, construction and building engineers are ill-equipped by their training to deal with the emergent issues of global warming, acid rain and other ecological and environmental influences.The steel industry must educate them against misconceptions and prejudiced views which pose a threat to the use of steel. Architects have the power to influence the consumption of energy in construction in the face of raised awareness of the potential damage to our ecological future.

Concern with the ozone layer, global warming, acid rain, diminishing rain forests and the depletion of vital reserves, and the ever increasing demand for energy, has meant that Ecology and the Environment is rapidly becoming one of the most powerful influences on the design process. This is leading to an emerging trend based on a response to these criteria. Whilst everybody talks about ecological building, few architects, construction engineers and building services engineers are truly able to deal with these issues. Their training has not prepared them. Consequently the steel industry must recognise that in order to prosper they must help designers with the critical information, without which, alternative design strategies based on misconceptions, prejudiced views and knee jerk reactions pose a strong, and unnecessary, threat against the use of steel.

The Habitat conferences and the Rio Earth Summit have already helped to raise international awareness of the potentially bleak ecological future of our planet if current trends continue unaltered. There is no question that architects influence energy consumption in construction.

There is no single prescriptive method of achieving sustainability. Steve Christer of Studio Granada in Iceland approaches things a little differently than Philip Cox in Australia. Irrespective of the contrasting climatic conditions the material infrastructure is completely different. Concrete is the material for the Steve whereas Philip uses the readily available supply of steel. In the USA timber is in plentiful supply and its not surpassing therefore that it is a common feature in ecological architecture.

Taking account of regional, national and international variations in materials, and supply chain infrastructure we will try to set aside the obvious and describe some contemporary design trends and illustrate the potential implications on the use of steel in environmentally responsible architecture.

The work of architects who aim to build with ecology and the environment in mind, tend to fall into two camps. In one camp are those who use earth or organic forms. They see traditional and vernacular methods and materials as the panacea for all environmental ills.

The resultant buildings are characterised by their autonomous services, turf roofs, generating their own electricity supply, recycling rainwater, featuring composting toilets, or are even made of mud covering old tyres and other discarded materials. Whilst praiseworthy in principle, they cannot often be called Architecture.

The other camp - the 'High-Techs' such as Future Systems, Sir Norman Foster, Richard Rogers, Nicholas Grimshaw, Michael Hopkins, Gunther Behnisch, Chaix and Morel and Chris Wilkinson are also contributing to the protection of the environment. They use modern technology and materials available to them in such a way as to minimise the strain on the earth.

These architects were educated in an era which put men on the moon via vast throw away rockets and later developed the technology into a reusable shuttle.

They too are also contributing to the protection of the environment. They use modern technology and materials available to them in such a way as to minimise the strain on the earth.

One of the most commonly adopted measures for saving environmentally precious resources is to fully utilise whatever is in free supply. Air: the wind, passive air-flows; Water: using the sea, rivers, dams, ground water; Sun: Passive and active systems; Earth; thermal and acoustic insulation, cheap building material; Fauna and Flora; and combinations of them. Trombe walls, photovoltaic cells, atria and large areas of glazing facing the sun may also contribute with varying degrees of efficiency and cost effectiveness. It can be argued that if some or all of these principles are adopted, irrespective of design style, the resultant work some have some environmental credence.

Of course there are architects who straddle both camps. They employ the imagery of the first, whilst using the technology of the second. Nial McLaughlin who won The UK Young Architect of the Year award of 1997. He employs some imagery of the 'greens', whilst using the technology of the 'Hi-Techs'.

This Shack is a photographer's studio designed by McLaughlin. The perforated steel canopies baffle the light, casting delicate patterned shadows in the interior.

His Mews House uses modern steel and aluminium glazing combined with traditional timber windows. Automated roof-lights are linked to weather sensors to induce natural ventilation.

It would be naïve to assume that the wholesale embrace of the ecological agenda will not effect architectural expression although whether the elements of energy control and sustainable material selection are overtly expressed remains the decision of the designer.

Designers of office workplaces are responding to users more demanding requirements of fresh air supply, closer proximity to windows, in buildings which are cheaper to run and easier to maintain. In many cases these short span, low technology solutions utilise a concrete structure which is left exposed using its thermal capacity to assist cooling requirements.

Large areas of openable windows maximise daylight with external solar shading and internal blinds controlling solar gain and glare. Some former noted specifiers of steel appear to have switched their allegiance to concrete framed solutions.

Whilst the switch to concrete is not universal, it can often relegate the use of steel to a thin cosmetic veneer without structural substance, or as an interior design element such as a bridge, applied within a heavyweight frame.

There are notable differences in approach to these issues between Europe and the United States.

The differences between Europe and the United States are highlighted in these two illustrations. They show the stylistic, technical and philosophical differences in design between Europe and America. The Berlin offices for Daimler Benz, have openable windows, partially exposed ceiling slabs to optimise natural ventilation and nocturnal cooling, with expressed articulated elevational forms.

The US equivalent has sealed windows with full air conditioning, albeit cfc free, regular suspended ceilings, with carefully designed lighting which has a low flicker rate and sophisticated Building Management Systems which reduce energy usage. The elevations remain traditional corporate downtown USA.

Whilst the idea of using a structure's thermal capacity is not new, some designers perceive that the greater the mass, the better the solution. In many instances this has been the result of mis-information especially pertaining to issues such as thermal capacity.

Tests have demonstrated that heavy mass structures are not necessary for high levels of thermal capacity and research has demonstrated that lightweight steel solutions can perform as well as their heavyweight opponents. One example in steel, which demonstrates a positive response to this trend is the Kimberlin Library Extension at De Montfort Univeristy, in Leicester England. Designed by Eva Jiricna Architects this building incorporates both passive and active features. The width of the building maximises the use of daylight via both translucent and clear glass permitting views out while controlling solar gain. The steel framed building with a regular grid allowed for fast and economic erection.

A mechanical fresh air system has been selected in association with pre-cast concrete floor planks as distribution, which utilises the mass of the structure for passive cooling. This system known as Termodek, is used extensively in Scandinavia, can produce high fresh air input associated with air movement without the need for chiller plant.

Another seminal steel framed building is the Commerzbank Headquarters in Frankfurt. This multi-storey breaks all the rules for this building type. It will be naturally ventilated for nine months of the year. It stands at the forefront of environmentally responsible modern architecture.

After undertaking a value engineering exercise, working with the Engineers Ove Arup and Partners, steel was selected in preference to a concrete frame because it was cheaper, of less weight and its slender columns maximised the useable floor area.