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Architects: kooo architects
- Area: 441 m²
- Year: 2023
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Photographs:Horikoshi Keishin
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Lead Architects: Shinya Kojima
Text description provided by the architects. On a limited 84-square-meter plot in Tokyo's central district, kooo Architects focused on the "gaps" within the urban fabric to design Hotel Rakuragu — a 9-story hotel with open views despite its compact site. Terrace: The area is surrounded by typical mixed-use buildings in downtown Tokyo, lacking scenic vistas or uniform design regulations for neighboring structures in height, width, or materials. Unlike typical Tokyo hotels that omit balconies to maximize room space, kooo Architects observed the surrounding buildings and oriented each floor's openings toward urban gaps, creating balconies in varying directions. Each room features a unique balcony design, allowing guests to experience diverse views from different floors. This approach resulted in a building that appears as a white cuboid carved with irregular voids, forming a rhythmic façade.
The plan grid (X1-X4) was vertically connected to optimize cost efficiency. By modifying the single-span structure at the X4-X5 axis, three distinct balcony styles were achieved, balancing functional needs with architectural expression. The terrace integrates passive design principles, enabling natural ventilation and light through Low-E glass. This balances openness with thermal comfort, mitigating summer heat and improving winter heating efficiency—a critical consideration during the COVID-19 pandemic design phase. Structure: The building's iconic form uses a steel rigid-frame structure with diagonal braces instead of conventional column-and-beam systems. This allows flexible column placement and minimizes visual obstructions on balconies. The facade has a rhythmic design, with balconies on both the left and right sides of each floor. Some balconies are triangular, while others span the entire bay. To achieve this design, we used a rigid frame structure with diagonal braces instead of the traditional column-and-beam structure. This approach allowed us to arrange the columns more flexibly, creating the desired space.
The signature feature is a balcony that offers a view of the city. The structure also provides guests with unique perspectives of Tokyo, which are not typically available in other city hotels. Columns and beams are compact (beam depth: 300 mm; column diameter: 150–200 mm), hidden within walls to maximize natural light penetration. Curved walls in guest rooms blend indoor and outdoor spaces, enhancing spatial continuity. Interior: Seamless spaces with curved walls and diatomaceous earth wallpaper create a soft, diffused light environment. The microporous texture of the wallpaper and wall curvature enhance both visual and psychological comfort. Bathrooms are strategically placed away from openings to ensure privacy (critical in Chuo Ward's office-dense area). The washbasin is relocated outside the bathroom, reducing spatial confinement while maintaining functionality. Rather than pursuing overtly striking aesthetics, Kooo Architects focused on the " Terrace " concept to shape the hotel's identity. Variations in balcony designs directly correspond to room types, achieving a balanced mix. This project exemplifies Japan's ingenuity in transforming spatial constraints into value, offering a stay experience that authentically reflects Tokyo's urban density.
