Model ministry.

Sauerbruch Hutton's competition-winning proposal for the new German Environment Ministry in Dessau provides a chance for politicians to put environmentally responsive ideals into practice.

The former East German city of Dessau will be the future location for Germany's new Federal Ministry of Environment. Conceived as a model project, the building complex will be ecologically conscious and cost efficient both to construct and maintain. Eventually it will also be linked with EXPO 2000 in Hanover as a special external exhibit intended to demonstrate Germany's ecological awareness and advanced technical expertise.

The Environment Ministry was originally set up in 1974 to provide the West German government with scientific advice on policies relating to natural resources, rubbish disposal and associated health issues. Its core department holds scientific archives and administrates research and investment. Five other departments are concerned with planning and quality standards, environmentally-friendly technologies, products and field experience, the testing and grading of materials, and the Institute for Water, Ground and Air Hygiene.

The decision to relocate the ministry from West Berlin to Dessau was made to help stimulate development in the economically depressed former East Germany. Lying to the east of the city railway station, the site was previously a gasworks. Further east, the river Mulde marks the edge of the city centre. Recycling inner city space, decontaminating ex-industrial land and developing brown sites for non-polluting alternative use are all familiar tenets of eco-aware politics and the Dessau programme has given the ministry the opportunity to put such ideals into practice. The building was put out to competition and won by the Berlin/London partnership of Sauerbruch Hutton Architects in March 1998. Their plan for the 17 900 sqm building includes public areas, offices, conference and educational rooms, services and infrastructure in a parkland setting. New landscaping binds the remaining nineteenth-century Worlitz railway buildings to the city centre and the new project.

Between park, city and preserved historical buildings the ministry is a mediating structure, a long curving strip through a new landscape. Entry to the complex is through a forum space which covers and hides two subterranean levels of parking. The building's narrow structure has a central corridor which allows maximum light and natural ventilation to offices on either side. The curved strip encloses a freeform atrium with access by open stairs and footbridges to the three upper levels. All public activities are concentrated in or around this atrium which is roofed with integrated photovoltaic and solar collector panels. Each of the four courtyards created between the three bridges is home to a different department, with the ministry's central administration located on the forum.

Each department is organized vertically with workshops and other large space requirements at ground level rising to sole office use at the top. Office levels are organized on a 1.35 x 2.70m grid allowing 10-15 sqm single offices and 18-24 sqm larger offices with 4.05-5.40m widths. This spatial flexibility continues on the east side of the strip, with set backs creating corridor niches for storage or office machinery and combi-use areas. Glazed partitioning prevents the central corridor becoming a gloomy tunnel and the grouping of meeting areas, visitor rooms and pantries at the bridge access creates a social focus for employees.

For such a model project, control of construction materials and processes is paramount. As a general policy, elements are to be as far as possible precast or partly assembled off-site. The building structure is a reinforced concrete frame with precast elements. Slabs will be delivered with integrated heating, electrical, data and cable trunking. The basic cladding module has two window strips and two timber-clad bands per floor. A glazed strip under the ceiling brings daylight into the furthest depths of the offices and an openable eye-level strip permits views and individually controlled ventilation.

The idea of a natural landscape is carried into the architecture with a rusticated plinth created by stone cladding on the ground floor walls. Tree stands act as lines of protection from prevailing winds, direct sun and vehicular traffic. A lake, of rain water and ground water, planted with rushes will improve the micro climate. Internally, plants and water will improve oxygen levels and biologically clean the air.

Aesthetically, eco-architecture continues to oscillate between an esoteric belief in everything classified as natural and the overt exploration and celebration of technology. On the evidence of their recent housing and commercial projects (particularly their newly completed Photonics Centre in Berlin-Adlershof), Sauerbruch Hutton have shown an ability to combine rationality with a new eco-aesthetic; modern without being overbearingly moral.