041BÖT is a 75-square-meter penthouse in Berlin by Christopher Sitzler Architekt. The apartment is unified by a single material decision: a continuous mahogany ceiling that runs throughout the entire flat without interruption. The panels are cabinet-grade quality, supplied by Europlac, and had to be coordinated with the lighting, ventilation, and structural requirements of the apartment, accommodating all of these systems while maintaining visual continuity. The ceiling reads as an unbroken surface across all rooms.

Sitzler describes the aim as creating open and generous rooms, offene und großzügige Räume, and the continuous overhead surface is the primary means by which that spatial quality is achieved in a compact footprint. Beneath the mahogany ceiling, a coordinated cast floor runs through the same sequence of spaces. The 2 horizontal surfaces, ceiling above and floor below, establish what the practice calls eine einheitliche, warme Atmosphäre: a unified, warm atmosphere that runs continuously through the apartment. The mahogany and the cast floor are chosen for how they read in relation to each other, warm overhead against the harder, cooler surface underfoot.

The project sits within Christopher Sitzler's broader practice focus on the renovation and conversion of existing buildings in Berlin, where his stated aim is to preserve and emphasize the original DNA of each structure while adapting it to current needs. The mahogany ceiling in 041BÖT introduces a new material character into the existing building while the spatial strategy of continuity, rather than division, gives the penthouse a quality of scale that its 75 square meters would not suggest from a floor plan alone.