Roof With 20 Concrete Ribs by Atelier Zafari: Berlin’s Modern Architectural Extension

Atelier Zafari’s Roof With 20 Concrete Ribs in Berlin Neukölln is a striking architectural intervention that transforms an old five-story factory building into a luminous and functional 250 m² extension. Completed in 2024, this project exemplifies innovative residential extension design, combining concrete construction, spatial clarity, and light-focused interiors.

Transforming a Historic Factory Into Contemporary Living

Situated in a historic factory complex, the extension redefines the existing T-shaped floor plan, composed of a side wing and an almost square transverse building. This configuration naturally creates two distinct backyards, adding private outdoor spaces for the residents. Access is thoughtfully planned through the existing stairwell in the second courtyard and an external elevator for the transverse building, while a secondary staircase in the first courtyard provides an additional escape route or potential entry point.

A Seamless, Detached Architectural Extension

The extension is formally detached from the original building, creating a sense of independence and openness. Upon entering from the stairwell, residents step directly into a transitional outdoor space. A 15-meter-long corridor, bordered by the firewall and the new structure, guides visitors to the central entrance. Beyond this, stairs lead to a spacious roof terrace, offering panoramic views of the surroundings.

Spatial Organization and Functional Rooms

Inside the extension, two rooms flank the entrance, each with a compact bathroom, ensuring privacy and functionality. At the heart of the unit lies the 120-square-meter main room, dominated by a signature architectural feature: the 20 concrete ribs.

The Iconic Concrete Ribs: Light, Shadow, and Monumentality

The concrete ribs span 12 meters across the building’s width and adhere to strict building regulations with a 70° inclined slope on the sides. Each rib measures 30 centimeters in width and is spaced 30 centimeters apart, generating a rhythmic sense of uniformity and structure. Fully glazed slopes allow natural light to filter in, with window profiles discreetly hidden behind the concrete frames.

This design creates an interplay of light and shadow, allowing the movement of sunlight and seasonal changes to animate the interior. The space transforms throughout the day and year, offering dynamic moods that shift with the light, making it feel simultaneously monumental, delicate, and ethereal.

Materiality and Purist Interior Design

The main room combines exposed concrete construction with screed flooring, emphasizing the room’s purist aesthetic and uniformity. The tactile concrete surfaces enhance the sense of solidity, while the minimalist flooring complements the light, airy atmosphere. This careful balance between robust materials and translucent spaces ensures a harmonious, timeless interior.

 A Masterpiece of Contemporary Berlin Architecture

Atelier Zafari’s Roof With 20 Concrete Ribs is a compelling example of how architectural extensions can respect existing structures while introducing modern design elements. Through the innovative use of concrete ribs, natural light, and spatial organization, the project demonstrates the potential of adaptive reuse, residential expansion, and monumental interior design in urban settings.