Youthful exuberance.

Peter Hubner has become well known in Germany, particularly in the Stuttgart region, for his radical participatory work, which started with a student hostel and continued with a series of youthclubs and schools (ARs June 1985, March 1987, September 1990, and March 1992).(1)

Not only has his collaborative, improvisatory method proved a pragmatic and extremely economical way of producing buildings, it also helps to generate and bind together a committed community of users, which continues even after the original self-builders have left.

So, when revisiting the projects of the 1980s, one finds not only that they are still operational and in good condition, but also that they have grown and changed. Hubner, asked when one of his buildings would be finished, once replied: 'Never, I hope.' More than any other architect I know he takes seriously what Giancarlo De Carlo called the third phase of the planning process: that of use and evaluation. The building is not a static technical entity or a self-contained work of art but remains in living dialogue with its users.(2)

Following his successful youth clubs at Stuttgart-Wangen, Herrenberg and Stammheim, Hubner was approached by the Stuttgart Youth Club Society to see whether something might be done at Feuerbach, a northern suburb close to Stammheim. The suggested site was in a narrow valley just outside the residential area, on a piece of ground owned by the city where a rain-water storage tank had recently been built. This enormous structure, some 36m in diameter and 5m deep, has a capacity of about a million gallons. It is not a reservoir, but a holding tank for storm drains, absorbing flashfloods produced by sudden downpours and then releasing the water slowly. Built as a purely technical installation and buried in the ground, it has no external identity and gave no clue of its dramatic purpose. From the start, though, Hubner saw it as a feature ripe for exploitation, and although the city engineers were initially adamant that there should be no building on top of it, they eventually relented.

As with earlier schemes, Hubner organised brainstorming sessions with the local youth to gather their suggestions for the club, and arrived at the concept of a Wasserschneckenschloss (water-snail-castle), an elaborate spiral structure including a solarenergy strategy. Excluded at this stage from the rain-tank's territory, it was to stand to the east, the side closest to the town, surrounded by its own moat in representation not only of the castle fantasy but also of the water below. In the mean time the mayor's office had been considering the accommodation of ever more numerous summer backpackers who were overpopulating the youth hostels. They were impressed by the arrangements in Munich, where since the Olympics of 1972 a large beer tent has been made available. For a tiny fee travelling students can have a safe shelter in which to lay out their sleeping-bags, buy a cheap meal and take a shower. The land in Feuerbach offered a good site for a Stuttgart version, for though a long way from the centre, it stands directly by a tram-stop. A tent was initially proposed on the open ground just beyond the proposed youth club and the rain-tank, and it was suggested that the backpackers might share services with the youth club.

Hubner thought that the whole thing could be more integrated and more permanent. For summer use, the accommodation did not have to be to a high environmental standard or quality of finish, and so could be accomplished relatively cheaply. The social and service facilities would serve the youth club for the remainder of the year, so would need to be closely geared to both uses. Then there was the rain-tank: its dull technical presence made a good piece of land sterile, but it could become an asset. Its heavy construction could serve as a foundation for the summer camp buildings, saving enormously on groundworks. These economies understood, the engineers were persuaded that the perimeter wall of the tank might be used, but its southern quarter was to be left clear for access. Eventually they agreed to allow light construction over the central area of the tank, provided that the loads followed its nine metre structural grid.

The main loads needed to be taken by the single perimeter wall, so were best cantilevered equally to either side. The timber struts would need to be clear of the wet ground, so it was easiest to raise the whole accommodation a storey and place it on top of the perimeter wall, which could then also be the enclosing element. So arose the concept of the Haus auf der Mauer, like the wall-houses on the edge of medieval cities. The three metre high concrete wall had to be specially built, but it precisely follows -- and reflects -- the tank structure beneath. The city wall encloses an outdoor room, the market place, concentrator of social exchanges.

Around the inside of the wall at ground level are service rooms and offices, while in the middle of the west side exposed to the morning sun is a cafe. This part of the building protrudes the most into the communal open space, and its straight front follows the structure of the water tank beneath. The curious and attractive curved eaves are the result of the conical roof being cut off in a straight line.

The accommodation follows two sections of the perimeter wall, generating long curved dormitories, just wide enough for people to lie radially on both sides with circulation between. It can be partitioned with curtains as required to differentiate between the sexes, and there are two staircases to the longer tract related to the respective bathrooms, so segregation is indicated but not rigidly enforced beyond the washing areas. Because of the perimeter length, sleeping capacity is considerable, but the curve breaks the visual continuity of the essentially linear arrangement and refers constantly back to the centre.

This is a building which encourages a sense of community by its very form, and gives a reassuring sense of protection to a traveller from foreign parts. But the circle is not as over-insistent as it might have been. The interruption of the perimeter wall for access to the tank seems a happy accident, adding variety and providing a site for the service gate. The paving of the central space in a squared rather than radial format also helps to relax the central concentration, reflects the grid structure of the tank beneath, and sets up an orthogonal relationship between the cafe and the as yet incomplete youth club building.

Back-packers arrive by tram from the city and are allowed to stay three nights in succession for eight marks a night (just over three pounds), rolling out their sleeping bags on the wooden floor of the dormitory. They can take a hot shower, buy drinks and snacks in the cafe, or cook for themselves, but they have to leave by nine in the morning and are not re-admitted until five, so they cannot lounge around all day. The only entrance is the door in the east side next to the office where staff can keep an eye on who comes and goes. The wider vehicle entrance on the south side can be opened for deliveries.

As in most recent Hubner buildings, construction was divided between professionals and a self-build group.

Contractors were brought in to erect the concrete wall and the prefabricated timber framing of the dormitory blocks, but the cladding, infilling and finishing were carried out by student volunteers and young people from international work-camps, led by staff from the Stuttgart Youth Club Society.

For some parts, second-hand materials were used. Amusingly, discarded bicycles became service gates and balustrades, but some 150 windows were obtained free from demolition sites and over 300 reject glazing units from manufacturers who had made them to wrong sizes. This meant that the fenestration pattern had to be improvised with available material, which adds a welcome variety to the finished building. Also second-hand and free was the paving of the central court. Its thick concrete slabs were part of the reinforced floor of a demolished roller-skating rink, and it proved cheaper for the demolition contractor to cut it into 1.5m squares, bring it and relay it, than to put the material through the cruncher for hardcore (in Germany unwanted material can no longer simply be dumped). Lines of bricks between the slabs enhance the square pattern and provide contrast of colour and texture. Imagine it instead in bare concrete or tarmac to realise how much the quality of this paving contributes to the character of the central space.

It was initially intended that the youth club be built as an adjunct to the hostel building at its northeast corner, sharing the market place of the hostel and its surrounding facilities. But the budget was cut, and a disproportionate amount of the cash available went into foundation works because the site was found to be made up of infill to an unexpected depth. So the youth club part of the project shrank considerably and has yet to be completed, even in reduced form. It will be built along the perimeter wall on the north side, between the two dormitory blocks. It should be advantageous for local youngsters from families unable to travel to meet their contemporaries from abroad. Also, since the hostel is only needed during the three summer months, it is desirable to animate and maitain the building during the other nine.

With his youth hostel, Hubner has once again produced an intriguing and unusual building on a relatively low budget, turning local conditions to account. And he has also shown how a monothematic technical apparatus, which might be seen as a blight, or at best as a necessary evil, can be transformed into something both socially useful and inspiring.

(1)The Architectural Review: June '85. Social process, p76-81; March '87. Hubner's hybrid, p69-72; September ;90, Green school of thought, p49-53; March '92, Stammheim community, p41-45. See also AJ 27/7/83. Student self-build in Stuttgart. p32-50; and AJ 23/1/85. Voyage of discovery. p42-47.

(2)Giancarlo De Carlo divided the design process into three phases; the definition of the problem, the elaboration of the solution, and the evaluation of the results; noting that in normal practice, the third phase is almost non-existent. With participation, he claimed, the users should be present throughout, so that: 'each phase of the operation becomes a phase of the design; the use becomes a phase of the operation and, therefore, of the design; the different phases merge and the operation ceases to be linear, one-way and self-sufficient ... The testing of the results is through the way in which the product is used and the verdict stands upon the degree in which the users' needs are satisfied. It is not only a question of practical needs but of creative needs as well. A work of architecture, besides improving the material conditions of those for whom it is built, should facilitate the human need to communicate through self-representation. Therefore the structure of the work should be arranged so as to permit continual adaptations and transformations, which can themselves become extensions of the design.' From An architecture of participation, Melbourne Architectural Papers 1972, published by the Royal Australian Institute of Architects.