The project’s defining transformation is the “squaring the triangle”: within this triangular site, two horizontal, rectangular buildings establish the new block edges along Lautenschlagerstrasse to the east and Friedrichstrasse to the west. This design creates a strong, four-sided figure with a spacious central courtyard, fully realizing the client’s vision for a cohesive, multifunctional development. This layout not only optimizes space but also allows for distinct separation of functions. For instance, the horizontal buildings provide a dedicated courtyard for the 24-unit residential building, lending it a unique identity within the site. Yet this is far from a single-purpose complex – KarLa integrates a dynamic mix of uses, including retail, offices, open and green spaces, restaurants, hotels, and mobility services alongside residences.

KarLa embodies a positive “interlocking” –  functioning as a quiet, secure, almost self-contained urban quarter while also bridging and opening up spaces. For the first time, Lautenschlagerstrasse and Friedrichstrasse are seamlessly connected. Green connections abound, with lushly planted facades lining the courtyard and framing its entrances and exits, each with a clear height of six meters. This design creates a literal “organic passageway” between the interior, exterior, and the two main streets. At ground level, pedestrian flow is revitalized by an activated base, with dining and retail opening onto the inner courtyard. With its balcony greenery and central trees, this space evokes a forest clearing at the heart of Stuttgart.

The offices on the upper floors are accessed from the street through grand lobbies and are also reachable from the courtyard. Designed in a ring-shaped layout, the 26 office units offer flexible floor plans, adaptable to each user’s needs.

In  urban development projects of this scale, sustainability is non-negotiable, and KarLa delivers on multiple fronts. Its multifunctional design synergizes essential elements of sustainable planning, integrating biodiversity, water retention, urban cooling, CO2 reduction, transport transformation, and energy efficiency.

True, subsurface construction consumes significant energy and generates CO2, and KarLa includes two basement levels for 120 cars (entrance via Friedrichstrasse) and 300 bikes (entrance via Lautenschlagerstrasse). But it’s also true that this approach actively supports the Stuttgart’s transit transition. Notably, three basement levels are remnants of the original structure. Rather than requiring further excavation, the lowest level has been filled with demolition concrete, forming a solid foundation that preserves groundwater.

At the roof level, functionality meets sustainability. Outfitted with PV modules to generate substantial energy, the roof also serves as a multifunctional roofscape – offering recreational areas, water retention zones, urban cooling features, and a biodiversity-friendly environment.