The former textile dyeing plant Schoeller Hardturm AG occupies an elongated plot between the River Limmat and Hardturmstrasse (sites A and B) and another plot at right angles to this (C). After the plant had closed at the end of the 1980s and anticipating the proposed new building regulations which would upgrade the riverbanks from industrial to residential and commercial zones, the owners invited 15 architecture offices to take part in a competition.
The volume joins the series of large, compact office and industrial buildings along Hardturmstrasse. Like the usual “modern” construction of office buildings, the structure is a simple framework with solid access cores, which is clad, illuminated and ventilated by a mostly glazed envelope.
The storeys are offset to differentiate between an entrance and a delivery side at ground floor level; the cantilevered upper floors also allow for sun control to the southwest and southeast.
The ribbon windows and parapets of the facade consist of clear and etched glass in metal frames. The advertising lettering of the tenants in various colours and sizes is applied directly to the panes and visible by day as an integral component of the facades. At night, the glazing is backlit.
Residential, office and commercial complex
The main interest lay in the two accessible sides of the oblong plot between street and river.
The commercial and office buildings run the length of the plot, with the residential volumes placed on top and at right angles. Together they form a cubic mesh, which constitutes a mould for the resulting interstitial and courtyard space – a semi-private area interspersed with trees.
The building structures are subdivided corresponding to the office use of the two lower floors or the residential use of the upper floors. They are superimposed to create a structural network on the street side. Towards the river, the parts of the building are separated and stacked as offset, individually perceivable volumes.
The facade is composed of two kinds of glass (greenish industrial glazing and clear window glass) and concrete in different finishes (cast raw and artificial stone elements).
from “Werkstoff“ Edition Architekturgalerie Luzern, 1993