Lutherannex

building within the existing

Excavations at the Luther House in Wittenberg, world-renowned as the birthplace of Protestantism, uncovered remnants of an annex containing Luther’s old study. Rather than erecting a provisional roof over the ruins, a more permanent solution was sought. Architekten Tillner & Willinger won the competition with an innovative transparent roof design of inflated ETFE cushions. The highly aesthetic and yet, low-impact and light-weight intervention elegantly ensures the protection of this historic monument and composes an ensemble of the Luther House, the excavations, the historic city wall and public space.

The transparent cushions are held in aluminum frames as a delicate steel structure retains the architectural form. The construction requires no supports within the excavated yard itself: it is fixed directly to the external facade of the Luther House by brackets on one side, while at the back of the old town wall it rests on pin-ended columns. The primary structure consists of tubular steel trusses that span 20 meters at 2.5 meter intervals. Steel cables and bracing-rods above and below the tubes take up wind suction and snow loads.
Working in close collaboration with structural engineer Rudolf Bergermann, the construction was designed as slender as possible. The smooth ETFE material has besides its lightness and strength a further important advantage: it is self-cleaning and thus, efficiently saves museum maintenance costs.