Design of the hotel: The south façade
Miniloftmitte is Berlin's uniquely designed apartment hotel. The owner-architects explain the design, and how they created an iconic hotel in Berlin's historic center. This article features the south façade.
Design Berlin: The context
The façade was one of the most difficult design aspects to solve. The political atmosphere surrounding architectural design in Berlin at the time when we were planning this building (1999-2003) oriented itself on historic models from the nineteenth century. In Berlin this means 'Lochfassade', or directly translated, hole façade, a word used to describe windows in a massive wall, generally made of stone, brick, or plaster. We believe this goes back in part to the failures of post-war modernist design on one hand, and the massive destruction of the city during the second World War. Berlin has yet to recover from its incredible loss of city fabric.
We wanted our design to fit into the local context respectfully, while clearly stating its orientation towards the future. The south façade was particularly important. It is the most visible part of the hotel because the southern neighbour is set back from the street, causing the street walls to open, shifting focus briefly onto the Miniloft building. This is an unusual situation in Berlin, which is based on a perimeter block urban design.
The design goal was to create a façade that would give this very small building a sense of largess, of generosity. To accomplish this we reduced the number of visual elements to a minimum through a design based on a pattern of vertical stripes of varying width, alternating between glass and aluminum.
We designed all the details to maximize the vertical impact of these stripes. To this end we split the two traditional functions of a window: using the glass stripes control the light, and the aluminum stripes to control the air. If you want to open a 'window' you must open a part of the 'wall'. This design feature allowed us to significantly reduce the framing elements that would have interrupted the verticality of the glass stripes.
To further heighten the verticality we designed a custom detail for the joints between floors, reducing the horizontal interruptions in the glass stripes to just two per floor.
By careful design we were able to conceal the many joints required in the metal elements, allowing the aluminum stripes to read as monolithic elements spanning the full height of the façade.
We invented a new method for constructing the aluminum panels to create a 3cm relief between glass and aluminum. This lends the façade a plasticity rarely seen in curtain wall systems.
The glass used in the façade contains sunshades which when closed eliminate 90% of the solar gain. This greatly reduces the hotel's energy consumption by mitigating overheating without air conditioning, while maximizing the sun's natural heating potential in the winter.