As an office building of post-war architecture and due to its central location, the "Haus Neumarkt" has a special significance for Cologne's city centre. After a large part of the post-war buildings gradually disappeared from the cityscape, a rethink has taken place in recent years. In order to preserve the architectural heritage, many of the remaining buildings were either completely or partially listed. Among them is the façade of "Haus Neumarkt", which was restored by Arup according to historical models and the latest technical standards.
As a result of a renovation in the 1980s that was not in keeping with the preservation order, the building had completely lost its original 1950s charm. After briefly considering a new building, the owner decided to preserve the "Haus Neumarkt", spanning almost 4,000m² and make it fit for the future as part of an energy revitalisation. Arup was commissioned with the architecture for the design of the building envelope, building physics and acoustics.
2,500t less carbon emissions
-10dBIndoor noise pollution
The façade is a great gain for the building and the surrounding area. In constructive cooperation with our authority, the experts from Arup have developed a variety of individual solutions that bring out the details and atmospheric effect of the 1950s architecture again. ” Rita Pesch-Beckers Gebietsreferentin des Stadtkonservators im Amt für Denkmalschutz- und Denkmalpflege in Köln (City of Cologne)
Reconstruction in line with historical preservation requirements
Protecting, regulating, representing - the functions of façades are diverse. As a connecting element between the interior and exterior space, they must also blend harmoniously into the urban appearance of the neighbourhood. "Haus Neumarkt" shows how this multifunctionality can be met in terms of design. Since improper renovation in the 1980s had left irreversible damage to the exterior of the building, we had to reconstruct the elegant natural stone façade made of Jura and shell limestone with the typical three-part Cologne windows as well as the characteristic black glass balustrades, taking into account current building standards and following the historical model.
Reduced energy demand
One of the greatest weaknesses of post-war buildings is their high energy consumption. Acting as a thermal blanket, the façade has a great influence on the energy performance of a building. To avoid affecting the slender silhouette of "Haus Neumarkt" through insulation, the façade was set slightly forward. The building could thus be insulated without changing its proportions. Through a combination of high-quality insulation, energy-efficient ventilation and cooling technology, and customised sun and glare protection, we minimised energy consumption and maximised the building's comfort.
Due to the inner-city location at a busy traffic junction, the façade has to meet increased soundproofing requirements. With modern soundproof glazing and all-round connecting frames, it was possible to reduce the original noise pollution in the interior rooms by around ten decibels.
As there are many valuable materials in the façade, we designed it in such a way that it can be reused or recycled at the end of the usage phase ”Andreas Ewert Architect and responsible project manager at Arup
As the economical use of raw and building materials is an important factor in reducing CO2 emissions, the focus is increasingly shifting to the reduction of resource consumption in addition to reduced energy consumption. The most sustainable building materials are those that are already available and do not have to be newly produced. This saves energy, raw materials, waste and ultimately CO2. In the spirit of the circular economy, we avoided composite materials as far as possible during the refurbishment. Instead, we used materials that can be separated by type and simple plug-in connections that make deconstruction easier.
Due to their narrow construction and the resulting low weight, post-war modern buildings are often more sustainable than solid structures. The opportunity for further sustainability potential arises by preserving the old building materials and structure and not constructing a new building. By continuing to use the reinforced concrete structure alone, it was possible to save approx. 1,600m³ of reinforced concrete and thus 2,500 tonnes of CO2 during the renovation of "Haus Neumarkt".