Description

Prior to the Industrial Revolution, societies had only a few construction materials and few forms of usable energy at their disposal. For this reason, all highly developed cultures that have created meaningful architecture have restricted themselves to the construction of heavy, solid buildings in order to do justice to both the physical and the psychological needs for a designed environment. The supporting structure and the envelope formed a single unit, while the third subsystem, which today belongs as a matter of course to a modern building, the technical services, were only integrated into the building structure in a rudimentary fashion.

Habitable living space could be achieved only by enveloping it with a large mass. A thick, heavy construction offered sufficient thermal protection and above all, possessed large thermal storage capacity. This latter characteristic of solid constructions has contributed more to habitability than is usually assumed. Its ability to absorb and store the heat supplied to it and then to give this heat up to the surroundings long after the original source of heat has been extinguished served in two respects for the regulation of internal temperatures. On the one hand, the masonry mass of a chimney absorbed the heat of a fire burning during the day and gave it up again to the house during the night hours. On the other hand, the solid masonry walls absorb heat energy when external solar radiation is intense and thus slow down the heating up of the interior rooms. After sundown, sudden cooling is prevented by the heat radiating from the thermal storage masses.

By the end of the nineteenth century, the development of new materials such as rolled steel and reinforced concrete had revolutionised the spatial possibilities and design of construction. The functions of the envelope and the supporting structure became increasingly separated from each other.

The performance of the supporting structure increased rapidly in comparison with the cost of its materials, and thin, flat materials such as glass and steel panels formed a thin bounding layer between inside and outside. However, this disentanglement and minimisation of supporting structure and envelope and the introduction of technical apparatus for climate conditioning required an incomparably better understanding of all aspects of building design, a situation which was initially underestimated by the planners. It is therefore understandable that since the invention of modern frame construction, the envelope has undergone a fascinating evolution, even if some of the consequences have been somewhat problematic. In particular, some of the significant aspects of a building’s energy balance did not receive the attention they merited.

Undoubtedly Ludwig Mies van der Rohe’s ideas and the office building projects he executed are among the aesthetic high points of this development. His 1922 project for a glass tower in Berlin has become iconic. Yet Mies created not only the conditions that made it possible to separate the envelope from the supporting structure, but at the same time, behind the wafer-thin curtain façade of glass, he also developed a polygonal floor plan which anticipates the open spaces for office organisation forms that were developed decades later. Naturally, this building is more the embodiment of an idea than a real building; it is absolute architecture, which, in its spatial unfolding, is sufficient unto itself. However, it also represents a radical declaration of independence from nature; the artificial air-conditioning on the basis of seemingly unlimited energy resources enabled a fully self-sufficient working environment cut off from the external climate conditions.

Over fifty years later, Norman Foster realised this polygonal floor plan for the Willis Faber office building in Ipswich. A reinforced concrete-framed construction with broad span and a 70-cm waffle floor slab, which, together with the light-weight aluminium louvre panelling suspended underneath it, accommodates the ventilation ducts for the artificial air-conditioning, enables an extremely deep free-form floor plan. The building adapts itself seamlessly to the irregular site, exploiting it to the maximum. This generates extensive and entirely flexible rooms ideally tailored for an open-plan office. A raised floor with a network of cable channels enables services to be supplied to each workplace entirely independent from the walls.

The exterior wall, fully glazed from floor to ceiling, creates optimum daylight conditions for the workplaces – at least for those in the perimeter zones of the deep building. Even the stiffening elements for lateral wind bracing consist of half-storey glass fins – every structural element that might obstruct the view outside is made of glass. The individual glass panes are fixed to the next highest pane by means of bolts and a continuous clamping strip; like a shirt of chain mail, the whole three-storey façade hangs from the topmost floor slab, only being stiffened against wind forces by the half-storey glass fins. From inside, there is an unobstructed view of the mediaeval market town. This glass architecture makes a final break with the inside/outside dichotomy. One gets the impression that the outer wall has dissolved.

The new building stands in the midst of the old town’s network of streets like a huge stone marker. During the day, it mirrors the houses facing it in the dark absorption glass that was implemented to protect against overheating by solar radiation. For this reason, the building volume appears unapproachable.

In the evenings or early in the mornings when the building is lit from within, this impression changes utterly. Suddenly the events taking place inside it become transparent to the observer, who is able to recognise the scale and the variety of the functions. In contrast, by day, the observer has the feeling that he/she has come across an alien element from another planet, a piece of polished magma, cold and perfect like the setting of a science fiction novel.

In spite of the protective glass used, the problem of solar radiation in summer could only be solved by increased air-conditioning. This building was planned even before the first energy crisis; selective implementation of modern technical achievements to design a crystalline building without regard to the points of the compass is one-sided; it is not an adequate solution to the problems that face us today. The following articles will describe dependencies on requirements and technical solutions that take into account the total system of the building in a much more complex fashion as well as aspects of sustainability.

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Originally published in: Rainer Hascher, Simone Jeska, Birgit Klauck, Office Buildings: A Design Manual, Birkhäuser, 2002.