The protected building “Zum kleinen Christoffel” dates back to the 13th century and is located directly on St. Peterhofstatt in the heart of Zurich’s old town. The renovation combined the two top floors into one large family apartment, adding a new bathroom and kitchen as the most significant interventions. The old risers were no longer intact and required the construction of a repositioned riser shaft from the basement to the fourth floor. This “liberation” made it possible to add an extra room in the previous location of the bathroom and kitchen. The new bathroom fits into the existing structure of the fourth floor and extends into the attic, where the same body functions as a kitchen. This intervention allowed for the reorganization of two floor plans with only one element.