Like many cities, Hesse's capital faces an urgent housing shortage. One solution is to expand existing buildings vertically. This approach was recently implemented in Wiesbaden's Rheingau district, where the GWW Wiesbaden housing association renovated and extended several residential complexes from the 1950s and 1960s—including the multi-family apartment building at Niederwaldstraße 46–48. Beyond addressing immediate housing needs, this strategy is ecologically sound, as it preserves valuable land and prevents urban sprawl. The extension designed by architecture firm grabowski.spork demonstrates how thoughtful vertical expansion can enhance both the new living spaces and the architectural character of the entire building.

To create the extension, the original roof structure was removed and replaced with a full timber-frame storey. This addition transformed the previously unused roof area into spacious, open-plan residential units. "The structural conditions were exceptionally favorable," explains Jan Spork of the Wiesbaden-based architectural firm. "The buildings' framework allowed us to retrofit elevator systems seamlessly." This capability proved essential for adding one storey to each of the two six-storey buildings, ultimately creating six new apartments in total.

A continuous frame of bronze-colored metal shingles creates a striking visual distinction between the new storey and the existing structure. Combined with recessed side surfaces and cantilevered terraces, this design establishes a clear separation while lending the buildings a distinctive new character—one that evokes charming observation boxes perched atop the roofline.

To complement the new addition, both buildings received updated thermal insulation and new balustrades or fully glazed loggias. The elevator retrofit required complete reorganization of the vertical circulation cores, followed by a comprehensive redesign of the stairwell entries. All rental units were simultaneously upgraded to current technical standards.

www.gs-architektur.de

Photography Credits:

Jean-Luc Valentin

(Published in CUBE Frankfurt 03|20)