"Etrium" Office Building in Cologne

Designed to accommodate a staff of 150 and to comply with passive-energy building standards, this development is an expression of the company’s philosophy of comfort and energy efficiency. One striking feature is the red coloration required by the client as a reference to the neighbouring brick buildings. A compound thermal-insulation system was finally chosen for the facade to help meet the stringent building physics specified for the outer wall construction. The sandy, shimmering surface was achieved through the use of glass granules in various tones from red to orange applied to the outer layer of rendering in a special thown-on technique. A further feature is the 28 cm insulation, mostly in a single layer, which exceeds the permissible dimension. Its use was allowed only after the system developer had declared his readiness to accept full liability. The polystyrene rigid-foam insulation sheets with rebated joints are adhesive fixed over their full area to the concrete walls and additionally dowelled in positions that are subject to strong wind suction. To prevent the spread of fire across this inflammable material, rock-wool strips were inserted – vertically next to the staircases and horizontally over lintels.