Built in 1967 the commercial building Bleicherweg 21 occupies a prominent location in Zurich between Paradeplatz and the railway station Enge. After the draw-out of an important longtime tenant the owner used the time for a complete facade renovation. After an architectural competition Peter Märkli was commissioned with the planning and execution on the base of his winning proposal. His proposal represents an important contribution to the handling of facade renovations. In contrast to the currently usual approach, the building after the renovation appears not newer and more contemporary but rather normal and corporeal. The existing, elegant and dark appearance of the building was considered to be appropriate to the representative location within the city. Therefore the solution proposed by Peter Märkli was to reuse the existing granite slabs of the facade, instead of disposing them of. After dismantling the stone slabs were comprehensively cleaned, cut to different measurements and reused as far as possible within the new structure. Around 90 percent of the existing stone slabs could be reused for the facade renovation. The continuous horizontal windows of the previous design were maintined, however articulated with newly added vertical components, which were inserted between the windows. These components are to be understood as a new interpretation of a pilaster and show abstracted capital and base. The pilasters are nearly as black as the parapets, but matt instead of polished. The pilasters were made of artifical stone, the appearance of this material is like an inversion of the granite (dark inclusions within gray for the artificial stone and bright inclusions in the dark for the granite). In addition, an uniform optical impression was reached through the installation of new railings on the main roof and attic terrace. According to the architect Peter Märkli the pilasters between the windows mitigate the strict horizontality of the building from 1967 and concrete pillars on the ground floor take the building down to the earth. In addition, the mezzanine, previously open and glassy becomes part of the facade through the use of artificial stone. In addition the redesign of the facade follows certain proportions. The main entrance is adorned by a relief of the sculptor Hans Josephsohn on the facade, as is often the case in buildings by Peter Märkli. In a second stage Peter Märkli was commissioned with the facade renovation of the neighbouring office building, following the same principle.