The renovation of the old chemistry buildings is nearing its completion. Four departments, (Agriculture and Food Science, Mechanical and Process Engineering, Computer Science and Environmental Sciences) are packing their boxes in preparation for their coming move. The renovated building complex provides workspace for 1,130 people–900 office workplaces and 230 in laboratories. It addition, there are 1,900 places in five lecture rooms and 20 rooms for seminars or practical work, as well as a cafeteria and a specialist library, all waiting to welcome their first users.

Room has also been reserved for students' organisations. VSETH with its organisational commission for events for students (KOSTA), the Student Discount Foundation (SSD) and the students leisure centre (StuZ) from the Leonhardstrasse and the Polyterrace are all united and newly housed in the wing of the brick building that looks out on to the Universitätsstrasse.

Concentration at two locations

The renovation project of the old chemistry buildings was just part of a whole range of improvements at the ETH main campus in the city, explains Rudolf Kühne from the office for property infrastructure at ETH Zurich. It was essentially a question of concentrating certain departments and institutes that, up until now, have been scattered in various locations on ETH Campus Hönggerberg and on Centre Campus in order to reduce rents, upkeep and investments for laboratories. While the natural sciences will be concentrated at ETH Hönggerberg, the engineering sciences (with the exception of construction and materials science) are located with the system oriented natural sciences at ETH Centre Campus.

A patchwork becomes a whole

The former chemistry buildings were a veritable patchwork of different buildings that had grown over a period of almost a hundred years. It comprised the oldest part, a brick building from 1886 from Bluntschli and Lasius (CAB), the T-shaped steel frame building from Salvisberg, built in the 1930s, and the concrete building with its striking tower and sundry additions and extensions carried out between 1951and 1973. With the decision to renovate and make new use of the complex, a unique opportunity presented itself to clear up this architectural patchwork and give the buildings their original harmony once again. Today the spatial relationships are clear and the wings have been brought together to form a united whole. Moreover, the T-shaped Salvisberg building has been given an external complement; by heightening this part of the building, additional space has been created for a seminar centre.

Similarities with the colonnades of the Semper building are evident. The freshly renovated brick building (CAB) counts as one of the buildings in the City of Zurich that is worthy of conservation. large

Objectives and economic limits

The renovation of the old chemistry buildings was carried out within strict economic limits and had to comply with various legal objectives. Things were complicated even more by the fact that numerous laboratories had become contaminated over the years and the rubble that ensued from their deconstruction had to be cleared in accordance with strict environmental laws (1).

Urban ravine: The bright green floor of the new, covered courtyard is still hidden under a protective sheeting. large

Those responsible for the project had to negotiate a fine line, especially with the renovation of the red-yellow brick building. With the transformation of this building of high architectural value they had to weigh up directives on protected buildings and the fire authorities on the one hand, and the high expectations of the Executive Board of ETH Zurich regarding the technical infrastructure on the other. The result is that users of CAB walk into modern offices and seminar rooms, but also into lecture rooms containing original furniture, or into a laboratory that has been preserved but will no longer be used as such. This mixture of old and new elements has greatly added to the inherent value of the building.

Courtyard as the centrepiece of CHN

The adjoining cement building (CHN) has also gained a new attraction in connection with its striking tower. The new centrepiece of the chemistry complex is a covered courtyard, where a glass roof allows the daylight to flood in. This courtyard, with its bright green floor, is conceived as the meeting place and central nerve of the building. By concentrating laboratories in a single "lab area", additional room has been created in the tower for very attractive offices and meeting rooms that offer incredible views over the city. The renovation of this part of the building brought up fewer problems than that of CAB. It is not a protected building and this meant that the planning only had to take into account security and fire directives. The latter were particularly strict for the renovation of the tower. Amongst the lift installations, for instance, there is now a second lift entrance especially reserved for firefighters.

Reduction of emissions and sustainability

Two further objectives were followed with the renovation of the old buildings; first, to reduce emissions in the university district of the city and, second, to lower the amount of energy needed to run installations. The objectives have been met by the choice of appropriate users on the one hand, and the saving of heating energy by the means of insulating facades, renovation of the windows and a warmth recuperation installation on the other. Future consumption levels of electricity and water will also be reduced and the pollution of the district fall, because usage level in laboratories has been reduced and the ventilation system improved. The renovated buildings also come off well with regard to sustainability thanks to the installation of a photovoltaic system.

Obstacles to building

Nevertheless, during the building phase from 2001 until today the ETH department of planning ran into many obstacles. The fire on the roof of the old chemistry building in April 2003 caused quite a stir. Fortunately, there was only limited damage. What was far more serious was the disturbed relationship between the constructor of ETH and the building contractors following various acts of vandalism. The most dramatic of these was certainly when someone threw a stone through the new glass roof of the inner courtyard CHN causing considerable damage.

Moving

The final step will have been taken after the planning department has moved. This has been long in the planning and the parties involved especially trained. By the 16th September all the institutes and departments will have moved into their new home (2).