The refurbishment of complex buildings that serve various functions presents a particular challenge. This project involves a building that was built in 1968 and has been in use since then by the local authorities and public companies of the city of Remscheid. However, one consequence of a reform of the city’s administration was that the existing facilities were only to be used by Remscheid’s waste disposal services, including their vehicle fleet and administrative departments. This changeover presented an opportunity to refurbish the building, which had begun to show signs of its age. Alongside the rectification of structural defects, the client’s wishes also included significant improvements to the functionality and appearance of the building. Satisfied users have become an important quality criterion for office buildings.

There were significant problems with the building. These were particularly evident on the facades and roof and with the building services equipment and fire protection, meaning that economically viable building operation was no longer possible. In addition, there were structural defects. Accessibility features for disabled persons such as a lift were lacking, and this was no longer acceptable for a municipal building open to the general public. The clearance height in the staircase was only two metres in places. A feasibility study showed that refurbishment was more economical than demolishing the building and rebuilding it, even in the light of the numerous problem areas. The additional costs for a new building were estimated to be around 40%, as the disposal of the reinforced concrete skeleton structure would have led to high costs.

One of the goals of the planned measures was to reduce the primary energy requirement from around 440 kWh/m² p.a. to approximately 136 kWh/m² p.a., which would in turn also significantly reduce the operating costs for the building. The heating requirement of over 370 kWh/m² p.a. was well above the requirements of today’s German Energy Saving Ordinance. The high energy consumption was caused by the very poor structural condition of the building, the high hot water requirement all year round for showers, and errors with the control system.

The energy and indoor environment balances of the building were monitored for two years after refurbishment. This work was supported by the German Federal Ministry of Economics and Technology as part of its “Energy-Optimised Construction” (EnOB) research initiative. User surveys were also conducted in order to investigate levels of workplace comfort. In advance of the EnOB project, an economic and ecological evaluation of various facade structures was supported by funds from the Deutsche Bundesstiftung Umwelt (DBU).