[Archive] As skyscrapers grow ever taller, how can they sensitively meet the street?
First published in the AR in October 1977
A grid-iron plan, high density, and a fixed plot ratio produced the canyon street. Much of the planning effort in down-town Chicago during the last fifteen yean has been spent on trying to undo this. Buildings therefore were allowed to go higher still, provided they stood back to let in more light and air. This raised a new problem for Chicago: what to do with these extra parcels of land?
The first solution was to pave it flat as in Mies van der Rohe’s Federal Government Plaza, and C. F. Murphy’s Civic Centre, both of 1964. Without question this is the most architectural solution, in that it allows the surrounding buildings to rise straight off an unambiguous base. On the other hand it does nothing for the people using the space, who feel exposed to the towering banks of windows rising above them and have no reason to stop in it. These first plazas are valued, but not much used: there are seldom more than a few sprinklings of people in them and these are scurrying along. The new buildings on these first plazas are transparent at ground level, so that the pedestrian gets the bonus of views into and through the adjacent ground floors. But as these ground floor interiors are themselves treated as extensions of outdoors the effect to the man in the street is rather like being in an aquarium: the view through is impressive, but not interesting or cheerful. This aquarium effect is most pronounced in the Federal Plaza, and it was doubtless to offset it, and to give people something vivid and striking to look at, that the authorities installed the Calder Flamingo.
An opposite approach was used by Perkins and Will when, in 1973, they built the plaza lying at the foot of the First National Bank of 1969. This is elaborately articulated, at three levels, with broad flights of steps, a fountain, clipped hedges-and much else besides. The sunken area of the plaza runs into the base of the building, suggesting uncomfortably that rats have got at the foundations. There is no good functional reason why a building should no come down to two ground floor levels, but it produces an uncomfortble, able, ambiguous effect. Apart from this, the plaza is an untidy piece of design: seen from above, it is a mess. But, it is a great social success and is thronged with people all the time.
There is thus an unresolved conflict between architectural values and public use. On the one hand buildings look best when they rise from a-single, flat, unobstructed plane: but, on the either, people need some articulation of the floor to encourage them to stop and sit down and they need a barrier against the surrounding masses of building. Perhaps the answer is a simpler, more classical arrangement than the one used here, in which the sinking of the floor occurs in the middle of the plaza and not against one of the surrounding buildings. The opening up of space round the foot of tall buildings throws into relief the problem of how the building meets the ground. Within its own terms of reference the Miesian formula, with its black colonnade and high ground floor provided a convincing answer. But one which is not applicable to a building with raking walls.
Again the Miesian convention of a black, recessive skin and delicate articulation is a correct clothing for a building-conceivedas-structure; it protects the man on the ground from the rhetoric of colossal height. The value of this can be seen by reference to the First National where the thicker, light coloured structural members are much more intrusive: these zoom down from a height and produce a conflict between their gargantuan properties and the world of little human ants which teems round their base.
The John Hancock Centre, of 1969 was contemporary with the First National Bank and, like it, has a raking profile. It is a more successful piece of urban furniture and carries the expression of the ‘building-as-structure’ a stage further. lt is amusing to reflect how uncouth it would have been if the diagonal struts had been picked out in a light colour. The John Hancock, too, has a sunk forecourt on the Michigan Avenue side. This is not damaging, architecturally, as it is too shallow, front to back, to interfere with the effect of a flat ground line; but it is not so inviting and is not so much used.
The next plaza in the sequence is the one created by Mies between One and Two Illinois Center (1970 and 1973).
This plaza shows how dependent the Miesian formula is on the shape and size of the spaces between buildings and on the degree of enclosure. For this plaza is on the edge of the built-up area and opens out at the ends towards the river and towards the lake. As the buildings are close together, anyone standing in the plaza is painfully aware of the deep narrow chasms of escaping space, The items on the floor of this plaza are not waste left behind by the builders but pieces of conceptual art. Here they are no help at all.
The Sears Tower of 1975, stands more or less in the middle of its site and, though the tower proper is set back from the street front on all four sides to let in light and air, it does not produce a plaza worthy of the name; but it raises in a special way the problems of how to bring a very tall building-as-structure down to earth. The Sears followed the precedent already set by the Hancock Center of a very squat plinth in which shop windows of ordinary height are inserted.
There is a visual logic in this for the minimal plinth reads like a metal shim. But though it is always better to have shop windows on a shopping street than none at all, they are so crushed in proportion and seem anomalous, like the holes cut to make windows in the home of the old woman who lived in a shoe. In the Sears Tower the sense of an unworthy coming down to earth is more pronounced since, on two of the frontages, the ground line is sloping and there are no windows at all on these sides. Thus it is that the Sears which is admirable in profile, when seen at a distance comes down to earth with an un-Chicagoan brutishness.
Chicago’s most recent open space is one of a different sort altogether which has been created in conjunction with Harry Weese’s Courthouse Annexe at the south end of the Loop. This designation is a euphemism covering a multi-storey car park and a short stay goal. When we recall how unpromising these two users are, this must be accounted a brilliant piece of environmental design. This end of the Loop is occupied by the relicts of Chicaco’s first high-rise age, by the Monadnock, the Old Colony and so on. The new tower is no higher than these: it is triangular on plan, stands in one corner of the site and leaves a rhomboidal shape which has been paved and planted with lines of trees. This regular, over-all, planting creates a texture rather than a form. Therefore this is an environmental, not a social, plaza which aims, not to draw crowds, but to bring light and air into the canyons of this part of the city.