A World of Experience with the Skin of a Dragon

Shopping Center ALEJA in Ljubljana, SL

With its compelling and meticulously realized concept, the newly-opened ALEJA shopping center in the Slovenian capital of Ljubljana, which was designed by ATP architects engineers (Innsbruck), offers the perfect platform for international and local labels in around 80 shops with a total of 32,000 m2 of lettable space. With its rooftop leisure, sport, and relaxation areas and its stylish food court, the technically and architecturally innovative building responds to the competition from online retailers while also giving space back to the surrounding urban district.

“Retail centers will only have a future if they become part of the city. At ALEJA, we successfully wove highly efficient retail architecture into a beautiful city and used the notion of the urban quarter to create a multifunctional meeting point with an optimal leisure quality and visitor experience,” says Philipp Pfister, architect and Lead Project Manager at ATP, highlighting the urban planning aspects of the building concept.

A design concept under the sign of the dragon
The architectural highpoint of the elongated volume is the façade, as a result of which Slovenia’s most state-of-the-art shopping center can be seen as a homage to the city of Ljubljana. In close cooperation with SES, ATP integrated the story of the founding of the city into the architectural language of the building envelope. Diamond-shaped stainless steel tiles imitate the scales of a dragon – the heraldic animal of Ljubljana.

These shimmer in a range of colors and finishes, as a result of which the expressive skin of the building alters its appearance with every viewpoint, every step, and every change in the weather. “If a tile is still warm due to the morning sun it is a richer magenta than the neighboring tile – and this adds life to the skin,” says ATP Innsbruck’s Head of Design, Paul Ohnmacht, explaining the aesthetic individuality of the skin of scales that is so characteristic to the dragon.

Thanks to the latest design techniques the high-quality retail architecture continues both outside and inside ALEJA. The district center has two basements and a ground and two upper floors. The main entrance opens onto a space for events with a fountain. The mall is finished in elegant materials including natural stone paving and is flooded with daylight. The upper level retail areas are linked by three bridges. Columns of vegetation and a tree provide vertical green elements that connect the ground and upper floors. Further vegetation, water games for children, fountains, and areas for sitting and relaxing ensure that the center acts as a dynamic urban square for all its visitors.

Energy-efficient and sustainable
The choice of the glazing and surface materials paid close attention to the objective of avoiding both the loss of energy to the outside and the levels of heat gain on the inside that would require excessive amounts of heating and cooling energy. “The very deliberately defined mix of strongly and less strongly printed and clear solar protection glass enabled us to ensure an extremely energy-efficient level of operation, despite the high proportion of glass in both façade and roof,” says Pfister. And this alternation of open, semi-open, and closed elements in the diamond-shaped glazed and tiled structure of the façade creates an additional experiential effect: When the sun shines into the building or clouds pass by, dramatic shadowy patterns appear on the floor.

Flexibility first
From the very start, the design process paid great attention to such special requirements as large free spans, light floor slabs, and geometrically free layouts. Slabs were pre-stressed in order to reduce their thickness and, due to their complex geometry, this partly required the use of special prestressing systems with subsequent bonding that are otherwise only used in the construction of bridges.

