Historical Museum Refurbishment, Hanover: “Art” of drainage by Sita Bauelemente GmbH

Navigating Heritage and Modern Standards: The Roof Renovation of the Historical Museum in Hanover

Balancing the preservation of a listed building with modern drainage requirements is no small feat. The renovation of the flat roof at the Historical Museum in Hanover required a solution that met legal drainage regulations, flat roof guidelines, and stringent DIN standards. Through an innovative drainage concept, the project team achieved consensus, ensuring both functionality and historical integrity.

The Historical Museum, located on the Hohen Ufer, showcases exhibits on the history of Hanover and Lower Saxony. However, its significance extends beyond the exhibits—it lies in the architecture itself. Designed by renowned architect Professor Dieter Oesterlen and opened in 1963/1964, the building incorporates the Beguine Tower, the last remaining city tower, and a section of the old city wall, including the stone quarry wall of the ducal armory from 1643-1649. These historical elements were integrated into the museum's polygonal, three-story structure, which is arranged around a pentagonal inner courtyard. Architect Willi Reichert, who advises Oesterlen's heirs on monument protection, notes, "As an internationally recognized museum and a key part of the cityscape, the Historical Museum is a listed building."

The Challenge of Renovating a Historical Landmark

The museum's extensive 2,620-square-meter flat roof, featuring four staggered shed roofs, had undergone multiple repairs over the decades but had never been fully renovated. The roof faced several critical issues, including water drainage failures, thermal insulation gaps, and problems with watertightness, surface protection, fall prevention, and lightning protection. Architect Willi Reichert summarized the challenge: “Monument protection had absolute priority,” necessitating a contemporary renovation that respected the building’s heritage while addressing its functional deficiencies.