Blue Box Built-In Shelving and Seating Define Berlin Flat

This article analyzes a rooftop apartment in Berlin’s Prenzlauer Berg that rethinks space by removing interior walls and establishing a reinforced inner core to guide circulation. The design introduces a signature blue millwork “box.”

The project transforms a fragmented plan into a flexible living environment, anchored by color, materiality, and light. Cross-ventilation and urban views are preserved.

Open-Plan Reimagined: From Fragmented Compartments to Cohesive Space

The clients appreciated the apartment’s cross-ventilation, but the many interior walls created small, disconnected rooms. To unify the space, the architects removed walls from the main living area and created a reinforced inner core to organize circulation.

An unused central fireplace and a stair hall to the roof terrace provided no place to sit or gather. The design team anchored the layout with a striking blue millwork “box.”

This blue box functions as a sculptural, built-in unit that defines the dining area without isolating it. It combines wall paneling, shelving, and a built-in banquette.

The blue box is stained rather than painted, so the wood grain remains visible and tactile.

The Core Design Moves

• Removed interior walls in the main area to improve cross-flow and created a reinforced inner core to guide circulation.
• Anchored the dining zone with a blue millwork “box” that acts as a sculptural mass within the open plan.
• Added a built-in, full-height closet and shelving unit with a transparent wood finish and mirrored panels to visually expand the space.
• Included a light blue curtain that can be concealed to open the apartment or drawn to separate the bedroom from social areas.
• Matched the palette with a butter-yellow sofa as a focal point and added a sloping blue ceiling to connect the spaces.

Materiality, Light, and Spatial Perception

The design uses carefully chosen finishes to maintain continuity across the apartment. The blue millwork is stained to reveal the wood grain, adding natural tactility.

The full-height closet with transparent wood and mirrored panels visually expands the space. The light blue curtain offers a flexible boundary between private and social areas.

A sloping blue ceiling ties the composition together and allows the living area, home office, and bedroom to flow into one another. This enhances daylight and spatial permeability.

The living area features a bespoke butter-yellow sofa—Sophia 3000—as a counterpoint to the blue tones and wood finishes. Natural light enters through a skylight, increasing the sense of openness in the taller, brighter room.

The material palette—blue, wood, and pale textiles—creates an atmosphere that supports both sociability and retreat.

Materials and Finish Details

• Blue millwork is stained, not painted, preserving the wood’s grain and warmth.
• Transparent wood finish on the closet creates a luminous surface, with mirrored panels to amplify the sense of space.
• Light blue curtain serves as a flexible boundary for room separation.
• A butter-yellow sofa adds a bold anchor within the cool-toned palette.

Circulation and Social Dynamics in an Urban Loft

Entry from the stair reduces visual clutter and leads occupants toward a defined, low, dark-blue box before opening into a higher, brighter zone. This sequence creates a flexible transition from private to social spaces.

The design encourages social gathering in the dining zone while keeping intimate areas, thanks to the curtain and the inner core that organizes movement and sightlines.

Spatial Thresholds

• The stair hall to the roof terrace becomes a celebratory ascent, reinforcing the vertical connection to the outdoors.
• The blue ceiling acts as a unifying motif, guiding the eye and reinforcing continuity.
• The curtain system provides adaptable privacy without sacrificing openness, suiting contemporary urban living.

Outdoor Connection: Roof Terrace and Views

From the interior, sky-blue stairs lead up to a roof terrace with built-in seating. The terrace offers expansive views over Berlin.

This outdoor space extends the living area and connects to the dining and lounging zones. Daylight is preserved throughout the interiors.

The upper room is light and bright, while the blue-tinted exterior edge creates a visual link between inside and outside.

In this Berlin rooftop project, the architects use a simple material palette and bold color to transform a crowded apartment. A strategic inner core helps make the home luminous and adaptable.

For retrofit or new-build projects in dense urban areas, the focus on circulation and flexible boundaries is valuable. Integrated millwork helps balance privacy, sociability, and natural light.

Key takeaway for professionals: prioritize a reinforced core to unify the plan. Use expressive millwork and design with light and thresholds in mind to improve cross-ventilation and social adaptability in compact city homes.

 
Here is the source article for this story: Seating, Shelving, and Spatial Definition—a Blue Box Does It All at This Refreshed Berlin Flat