Special design features of the building The design concept for the renovation of the interior of the department store followed one main principle: the central atrium should become the store’s new nucleus and the central orientation point of the building because this is where the horizontal and vertical visual axes and the main building access are united. To this end, the ceilings of the individual levels were rounded and “rolled” upwards. In this way, the atrium expands up towards the retail levels, appearing larger and more open than in its previous incarnation. The atrium and retail areas seem to melt together, bringing the individual levels into a mutual dialogue and making the store into a special continuum. This effect is supported by the lighting and materials strategy: Both the materials and the manner of material transitions within the individual levels are also present in the atrium (large perforated metal areas appear as if emerging from a white foundation). The light fixtures, placed freely on the ceilings of each level, cover the rounded curves of the atrium and the escalators, until they are transformed into light points vertically set in the perpendicular cladding of the central room. Overall, the atrium appears light and dynamic – the relatively short individual levels now appear lofty and higher. The retail areas of the new store are distributed like ice floes on each level. These floes are marked by a change in floor covering and ceiling material, thereby forming a starshaped pattern of paths on both the ceiling and the floor. (see “Functionality” chapter) In this way, the materials on the floor and ceiling facilitate orientation within the building. Paths and retail areas are explicitly marked and visible from afar: Large perforated metal areas in the ceiling demarcate the retail areas. These areas form a multifunctional, highly flexible ceiling system and house the primary technical installations, security technology and product lighting. In contrast, the network of paths is mirrored with a high-quality plasterboard ceiling. Both ceiling concepts flow in rounded edges up over the entire atrium. Together with the escalator panelling, this creates a unified effect that stretches across the entire interior of the Gerngross department store. The interior is then expanded via resting stations, sitting lounges and temporary displays. Blending in with the environment Embedded in a dense urban setting, the Gerngross department store is one of the largest buildings on Mariahilferstraße, with two visible facades that are approx. 60 and 80m long and 30m tall. Prior to the renovation, the store had the appearance of a hodgepodge assembly of design elements from diverse construction periods, styles and architectural designs. There was a complete lack of higher design sensibility or clear architectural approach, and a tangled network of logos cluttered the façade. For this reason, one of the core objectives of the renovation was to create a harmonious design concept for the façade, which also had to be cost-effective: The façade of the new building forms the logical continuation of the interior: the ice-floe theme of the interior space continues on the new façade. To this end, large-scale, amorphous colour fields were applied. Leaving some space in between, an ornamentally designed, semi-transparent white area was then attached. Together, these layers form a conglomerate of light and colour. In the evening, this effect is reinforced by a lighting concept between the two layers of the facade. A large-scale white frame also emphasizes some areas of the facade (e.g. main entrance, bay), thereby showing them off to their best possible advantage. The large scale of the façade harmonizes the entire building and emphasizes its true size. Advertising media, such as logos and slide-in plates, have been aggregated and drastically reduced as compared to their former state. The ornamental pattern was designed to ensure a continuous view from the building into the street space (50% free cross-section). Furthermore, the entire façade was thermally reengineered and technically modernized, so the ornamental pattern functions simultaneously as sun protection. The “Tilting Effect” Depending on their viewpoints, viewers will perceive the facade differently: From a level viewing angle, it appears more like a white-ornamental field. As the viewing angle gets steeper, the background colour of the building comes more strongly into focus. This creates a tilting effect, which follows the passers-by. Functionality One of the main issues with the existing building was the store’s confusing layout. Customers found it difficult to navigate, the individual retail spaces were poorly laid out, and important infrastructure elements (e.g. customer elevators or restrooms) were nearly impossible to find. To remedy these problems, the levels that feature smaller retail spaces (G, 1st, 2nd, and 5th) were redesigned to conform to a star-shaped layout that is more appropriate for a department store. Starting from the centrally located atrium, star-shaped pathways provide a clear organization of the retail spaces on each level. The individual shops are demarcated by different floor coverings and ceiling materials (see above). For visitors, this creates a visual orientation system that is easy to navigate and makes the department store feel both commodious and tidy. Furthermore, despite the relatively low ceiling height, the strong harmonization of the ceiling provides an open, spacious feeling. In addition, this layout strategy places the retail spaces in an optimal setting and also makes the important facilities east to find. Striving for innovation and conservation The “Loop” ceiling system, which has already been awarded the “Innovationspreis Architectur und Bauwesen” (Innovation Prize for Architecture and Construction), was developed in cooperation with the company Durlum especially for the Gerngross project. This highly flexible system offers the following advantages over conventional ceiling systems: 1. The lightening system (basic and emergency lighting) are directly integrated in the ceiling system and are therefore both invisible and glare-free. 2. Effect lighting systems can be flexibly installed through the ceiling, which provides maximum flexibility for making adaptations, such as for new product designs in the retail space. 3. The design of the ceiling allows the ventilation outlets to be placed above the ceiling while still retaining their full effectiveness. Therefore, the vents are invisible, and the ceiling surface is harmonized and is not visually disrupted. This design was also tested in several aerodynamic test runs at the University of Vienna. 4. The optimal joining of the ceiling islands makes the seams virtually invisible, which gives the ceiling the appearance of a continuous, unified surface. Ecological and sustainability aspects (in particular resource conservation) during construction, operation and demolition, as well as the choice of power supply and building materials Since the adjacent car park provides only 300 spaces (which are available to the general public, and not just to Gerngross customers), the majority of customers use public transportation instead of private automobiles to visit the store. This fact alone already contributes to ecological sustainability, resource conservation and emission reduction. In fact, the department store is ideally linked to public transportation, as it virtually has its own subway station right below the building. On peak days (such as before Christmas), this optimal situation has allowed up to 70,000 people per day to pass into the store. Furthermore, the entire façade was thermally reengineered, all windows were replaced, the building’s technology was brought up to date, and building components contaminated with asbestos were carefully removed and disposed of. In addition, the lighting system was energy-optimized in terms of the relationship between power consumption and heat generation (with the goal of minimizing the demands placed on the air conditioning system), and the emergency lighting system was executed with LED technology.