The "vernacular" use of steel

Vernacular architecture is linked to the traditional uses of building materials where these traditions have been developed and refined empirically over many years. Such a building is illustrated by the cottage shown.

Here the soft chalkstone walls have been given a waterproof plinth in an attempt to stop the water rotting them at the base, a lightweight roof covering of thatch and small window openings. Moreover the more expensive material of brick is used for the chimney stack where the soft chalk would be inappropriate. The method of assembly of the cottage could be said to be in the craft tradition in that the method of assembly remains relatively constant, only changing slowly in response to technological developments.

Given such a definition of the term vernacular it is only possible to apply it loosely to the use of steel in architecture. The development of steel as a building material has proceeded in step with the development of the technologies brought into being as a result of the industrial revolution. Thus the material was developed alongside the methods necessary for its assembly into the components, whether structural or non-structural, of a building.

The similarity of using steel in a vernacular way to the Arts and Crafts movement is in that the architecture is intended to result from the appearance and properties of the materials used and the way in which the properties of the materials dictate particular building details.

The relationship between this approach to design and the Arts and Crafts movement is strong, in that the architecture is intended to result from the appearance and properties of the materials used and the way in which the properties of the materials dictate particular building details. The simple white roof of the Guest House for Missionaries in Dar-es-Salaam by Hubert-Jan Henket illustrates the way by which the detailing of a simple material such as flat sheets of corrugated steel can be used to create a shelter both in terms of climatic modification and through the symbolism of the haven that may be found under the white roof.

As Peter Buchanan says: "Hubert-Jan Henket intended his building as an unextravagant model for the tropics, meeting the challenges of the climate yet requiring minimal maintenance and mechanical ventilation...Seven degrees south of the Equator the climate is hot and humid, so continuous air movement is required for comfort. Natural air movements are the land and sea breezes (at night and day respectively) and seasonal monsoon winds from east and south-east and the stack effect caused by hot air rising within a confined space. The building is designed to exploit all these as well as the turbulence from tall buildings around, which causes winds to gust from all directions. Accommodation is in two raised parallel wings joined towards either end by chapel and dining room and so enclosing a narrow court open to the sky above and the streets below. Circulation is via open balconies, so each wing is one room deep with tall louvered windows and doors angled to welcome in breezes from any direction. Broad overhangs shade the windows and allow them to be left open in downpours while thermal mass is generally kept down to minimise the build-up of heat. The off-white coating of the corrugated steel sheet roof reflects 55 per cent of the heat falling on it and a well-ventilated cavity below it allows most of the heat absorbed to be carried away.

 

The diagram illustrates the principles involved. The Guest House for Missionaries uses a simple, standard material in an uncomplicated way to produce an architecture that responds to its climatic environment and yet exudes, "a quiet, confident and pleasurable sense of authenticity that will not quickly fade."

An excellent example of corrugated steel used to create a 'roof of welcome' is the Health Centre at Marienburg in Surinam, designed by Lucien Lafour and Rikkert Wijk.

The same material of corrugated steel has been used to create a roof of welcome over the Health Centre at Marienburg in Surinam, designed by Lucien Lafour and Rikkert Wijk.

In the words of Aldo van Eyck: "In the tropics an awful lot of people often wait long and patiently every day for something that sometimes isn't there at all - in dust and appalling heat. People in Marienburg who go to Lucien's clinic ill, weary and apprehensive will be made to feel a bit better by the way the building receives them and lets them stay. If this isn't a good and beautiful building, I don't know one."

The plan organises the building into three sections, the polyclinic which is freely open to people, the ward area which is private and a work area between the two zones.

"Polyclinic and wards are loosely arranged as pavilions under a huge oversailing roof which, reflecting the plan organisation, is composed of several independent roofs and awnings. Concrete columns support concrete gutters which serve as beams between which span the roof trusses. Over the waiting areas though half trusses span to timber posts from which rafters extend awnings to protect waiting areas and terraces and so welcome visitors by sheltering even those who have not yet entered. The roofs are well insulated and the ridges capped with ventilating monitors with double banks of louvres."

The relationship between the function of the roof as an external surface that diverts water in an area of high rainfall and an internal surface that provides shade in the hot sun following the heavy showers is further described by van Eyck:

"The clinic is characterised, it seems to me, by the way it receives people all round at the sides as generously as it catches the rain all round from above, for the 'gutters' here are at the same time roofs, actually of the concrete verandahs below. These support the wooden canopies, which work like enormous lungs. A real boon, that great shady world underneath, where there is always a bit of a breeze. It could be said that there is a good understanding here between the building and specific local circumstances, wind, rain and heat. And in this connection, look how sunlight and shadow, light and dark, inside and outside, open and closed, appear to full advantage both in gradation and contrast - everything diversified, adjustable. Without expensive mechanical aids, a good climate is achieved by means of the building itself."

Glenn Murcutt's designs join the style of the traditional Aboriginal bark huts with the permanent stone architecture and the skills of using materials such as corrugated iron sheets brought to Australia by the new settlers. His architecture is genuinely Australian.

The vernacular tradition of Australia and New Zealand is itself different from that of the permanent settlements of Europe. Using the example of Australia the Aboriginal bark huts were built as temporary structures that were "to touch the earth lightly". When the European settlers arrived although they brought with them the permanent stone architecture of Europe they also brought prefabricated buildings which used materials such as corrugated iron sheets. A new vernacular tradition of buildings made from these standard dry-constructed components developed. These two traditions have been united in the work of Glenn Murcutt who has explored the form of the simple hut and related it to the materials of prefabrication without ever forgetting the particularities of the site in an attempt to develop an architecture that is genuinely Australian.

The house at Moruya, New South Wales designed by Glenn Murcutt is an example where standard parts have been combined to produce a building directly related to the Australian rural environment. 

In the House at Moruya, New South Wales which was built for a family who had camped on the site for many years, the rectangular box, divided into bays with a service wall along the north side, is topped by an asymmetrical roof of curved corrugated steel.

As Rory Spence indicated: "Murcutt developed this early in the design, as a response to the site - to the rhythms of the curved folds in the hills around the house, and the waves of the sea. He also wanted to suggest flight, perhaps in response to the seagulls and eagles which glide overhead on the strong coastal air currents, and he wanted to give the house an openness and lightness analogous to the experience of camping under canvas.

The planning of the house divides the single volume into a series of separated bays for living and sleeping areas for the parents and their children and their friends. The bays are linked by an implied corridor created in front of the service zone which, with the north wall, buffers the living space from the cold southerly winds. In addition:

"the south wall has only one window, in the parents' living area - a framed view of the hillside behind - but there is the continuous fixed clerestorey above, set out from the wall at its lower edge to accommodate timber ventilation panels, in the horizontal plane, operated with a pole from inside. Thus, all internal spaces can be cross-ventilated, while the doors in the spinal corridor can also be opened up to create an east-west breezeway. On the north and east walls the roof overhang shades the unprotected clerestorey between the equinoxes, and shades the whole wall for two and a half months around the summer solstice. In mid-winter the sun penetrates right into the spinal corridor, but can be controlled by external louvre blinds operated from the interior."

The standard parts both spatially and materially of the Australian rural shed have been combined to produce a building that is directly related to the climate and form of the place and yet it retains the quality of the deliberately man-made object within the landscape that denotes the presence of architecture.

Corrugated steel has been used for the low budget offices in Vicenza designed by Renzo. Vernacular use of steel implies that standard components will be assembled on site in a more or less standard way, unlike the Arts and Crafts movement where the skill of the individual craftsman was inherent in the use of traditional materials such as masonry and timber.

In a different context the inherent strength of the curved corrugated sheet has been used by Renzo Piano to provide offices at Vicenza on a low budget.

The small, "steel and glass catenary tent" provides an extension to an existing factory for office workers. Piano himself said:

"Form as form does not interest me. Of course, space is important. But I never start by saying "what magic space might we create here?", and then follow with technique. The two come, must come, together."

Thus, Piano underlines his allegiance to the vernacular tradition in that the technique of putting together the available materials will itself, in the hands of the designer, be capable of producing architecture. Unlike the philosophy behind the Arts and Crafts movement where the skill of the individual craftsman was inherent in the use of traditional materials such as masonry and timber, the vernacular use of steel implies that the standard components will be assembled on site in a more or less standard way. The input of the craftsman is, therefore, negligible (except where things go wrong on site) and the skill rests with the designer in selecting both the best components for the task and the best method of site assembly. Piano uses the economic constraints of the brief to create a unique space and form:

"The catenary shape, for cheapness, was obvious; a tension structure with a system of steel struts and ties supporting pre-formed inverted steel arches at 3m centres. Sheets of corrugated steel span between, as permanent shuttering for the 80-100 mm layer of concrete which, beneath 50 mm of insulation and a waterproof membrane, keeps the structure steady.

The lopsidedness of the catenary curve, with openings at the top, helps to encourage the natural stack-effect ventilation and cooling in summer, but there is mechanical cooling too which ingeniously combines local custom with what might be regarded as local raw material. Lowara (the parent factory) is a manufacturer of pumps; the attached factory is where they are made, and to help cool this office extension to the building in summer several of these pumps are mounted on the roof to spray the curved surface as required with water, whose absorption of latent heat of evaporation cools the roof and, in turn, the space beneath. It is a variation of the bottle-of-milk-in-wet-sock principle, and it would come as no surprise, perhaps, to those Italian shopkeepers who customarily spray with water the asphalt in front of their shops in summer, to find that it works, and that the interior is always pleasantly cool."

Apart from using the form of the roof as an element in the modification of the internal environment so as to avoid the use of a conventional highly serviced solution, the curved roof form that covers the corridor is used to reflect light into the space. These panels are made of curved corrugated steel which is painted white and light entering through the glass clerestorey is reflected back on to the roof of the corridor and back into the building. Under the main curved roof artificial light is also reflected from the corrugated ceiling to provide a ripple across the surface. This is a richness of architectural experience resulting from the careful execution of a simple structural idea.

The civic centre in the small Canadian town of Flin Flon, Manitoba by the IKOY Partnership uses prefabricated steel components which have a rational clarity and come together solidly, attractively and precisely.

The civic centre in the small Canadian town of Flin Flon, Manitoba by the IKOY Partnership takes the idea of the assembly of prefabricated components as the means of creating an appropriate architecture a stage further.

As Forrest Wilson states:

"Plainly a building assembled of industrial parts, the Provincial Center recognizes the disappearance of handcraft and celebrates the skill of building assemblers. It celebrates technical organisation. Sophisticated technology in today's buildings is found not in their form but in their automobile-like assembly. ...The Provincial Center asserts the creative ability of assemblers and sits comfortably with automobiles, the primary contextual reality of our time." 

The Provincial Center serves what was once a "tent town" some 400 miles to the north of Winnipeg when gold was first discovered there 50 years ago. As mining was established the town changed to a small scale vernacular of frame structures, often put up by the owners, punctuated by the larger mine head gear. However, the new building makes no attempt to reflect this existing vernacular.

Rather, the building that contains the government offices and the courtroom which are clustered around a glazed entrance court, remains an industrial building in an essentially industrial landscape. However, the building celebrates rather than apologises for its industrial origins.

"Each piece of the building was designed and fabricated far away, brought to Flin Flon, and installed on the site. Each part could be fitted in no other way than it now appears in the building...Assemblers do not want to puzzle over how a building fits together. They cannot indulge in this luxury when their boss demands they assemble 17 buildings a day. But if the elements have a rational clarity and come together solidly, attractively, and precisely, the "erector can work efficiently and take pride in his accomplishment."

The designers executed these ideas through the use of steel columns and steel trusses and corrugated aluminium cladding. Attention was paid to the lifetime of the different building components so that parts could be replaced as was necessary without the destruction of the whole. This was exemplified by the separation of the services and plant:

"The mechanical systems of the Provincial Centre are in a separate building, umbilically connected to the working spaces. New systems can be installed in a day without disturbing the workings of the court or offices. The building says clearly that its value is that it can adjust over time and retain its worth."

Both Glen Murcutt's designs and the Poole house explore the use of standard steel components to enclose and create spaces. The designs show the unique opportunities offered by steel in creating a ‘new vernacular’.

The Poole house bears comparison with that of Glen Murcutt above. Both have used existing components and produced architecture through the way in which these components have been fixed together in order to enclose appropriate space. Both houses attempt to introduce a new "vernacular" tradition not through the use of materials that have been around for centuries, since there are none, but through the obvious use of simple materials that modify climate and, rather than blending in with the land from which the materials have been taken as happens in the western vernacular tradition, sit lightly on it in the Aboriginal tradition of the Australian sub-continent. In this context the properties of standard steel components offer a unique opportunity to the designer seeking to create a new vernacular.