Kaktus Towers in Copenhagen / BIG, Innovation
- Mark Lafond, RA
- Sep 22
- 4 min read
Sustainable Change Models of Innovation
Introduction
The Kaktus Towers in Copenhagen are among the most distinctive residential buildings designed by Bjarke Ingels Group (BIG). Completed in 2023, the project rises above the Vesterbro district as two angular high-rises punctuated by jagged balconies resembling the spines of a cactus. Beyond their sculptural form, the towers represent a new paradigm of urban micro-living in Denmark. They integrate prefabrication technologies, modular interiors, and shared amenities into a vertical community that is affordable, efficient, and socially oriented. This article examines their architectural features, costs, technologies, smart building innovations, and concludes with a detailed list of construction specifications.
Architectural Features
The towers are designed to stand out against the Copenhagen skyline, with bold geometries and an aesthetic rooted in rotation and repetition. Each of the two towers, one approximately 80 meters tall and the other about 60 meters, rises from a shared green podium.
The most defining feature is the serrated façade created by rotating floor plates, resulting in angular balconies pointing outward in multiple directions. This design not only creates a dynamic visual effect but also ensures unique views from each apartment. From afar, the sharp balconies evoke the silhouette of a cactus, which inspired the project’s name.
The buildings house 495 micro-apartments, averaging about 30 square meters each. These units are arranged around central circulation cores for efficiency. The interiors feature trapezoidal layouts, a direct result of the angular façade geometry. BIG embraced these irregularities by designing modular furnishings that adapt to unconventional corners. Living spaces double as sleeping and dining areas, offering flexibility within compact dimensions.
The towers are raised on a podium that serves as an elevated public park. This “floating plateau” provides greenery, walking paths, and gathering spaces above ground level, visually and physically linking the residential towers with the surrounding neighborhood and the Dybbølsbro train station.
Technologies in Design and Construction
Kaktus Towers are defined as much by their construction methods as their form. Prefabrication was central to their development, ensuring cost efficiency and high-quality finishes.
Prefabricated Bathrooms: Each apartment includes a custom-designed, trapezoidal bathroom pod delivered and installed as a single prefabricated unit. These Green Box modules include high-quality finishes such as panoramic mirrors and efficient fixtures, differentiating them from typical micro-apartment bathrooms.
Façade Modules: The façade was assembled from prefabricated balcony and panel modules manufactured off-site. This allowed precise construction of the serrated geometry, minimizing delays and disruption in a dense urban context.
Structural Efficiency: Although the towers appear complex, the design relies on repeated skewed slabs. The rotation of identical floor plates creates variation while maintaining structural simplicity. The result is a cost-conscious system that maximizes net-to-gross floor area ratios.
Transit-Oriented Development: Located adjacent to Dybbølsbro station, the towers are designed to integrate with public transit infrastructure. The commercial plaza at the base reinforces connectivity between residents, commuters, and the surrounding neighborhood.
Smart Building Features
BIG approached the Kaktus Towers not just as housing but as a prototype for intelligent urban living. Several smart features define the buildings:
Modular and Flexible Interiors: Custom furniture systems allow small units to serve multiple functions. Beds transform into sofas, and dining areas double as workspaces. This efficient use of space is a form of spatial intelligence, optimizing living conditions without relying solely on technology.
Community-Oriented Amenities: The towers include shared facilities such as outdoor kitchens, a café, laundry facilities, fitness zones, and party rooms. These spaces reduce the isolation often associated with micro-living and encourage social interaction.
Sustainable Prefabrication: Prefabricated bathrooms and façade modules reduce construction waste, improve quality control, and shorten construction timelines. This sustainability strategy aligns with Denmark’s emphasis on green building.
Energy and Connectivity: While the towers are not explicitly marketed as “smart” in terms of IoT integration, their prefabricated systems and efficient layouts set a foundation for future digital monitoring. Shared facilities, lighting, and energy systems are designed for efficient management and integration with city infrastructure.
Innovations in Urban Living
The Kaktus Towers go beyond architecture and function as an experiment in urban lifestyle design.
Micro-Living for Youth and Students: With an average apartment size of 30 square meters, the towers address Copenhagen’s growing demand for affordable housing targeted at young professionals and students. By providing compact private units supplemented with expansive communal spaces, BIG creates a balance between privacy and community.
Vertical Community Model: The emphasis on shared amenities fosters collective living, positioning the towers as vertical neighborhoods. This approach contrasts with the isolation of traditional apartment towers, responding to social shifts toward co-living.
Green Public Realm: The elevated park at the base provides a unique public amenity. By lifting greenery above street level, the design ensures that valuable urban land doubles as both housing and open space.
Architectural Iconography: By evoking the shape of a cactus, the towers serve as a visual landmark in Copenhagen. Their spiky profile challenges conventional residential architecture, transforming affordable housing into sculptural urban art.
Conclusion
Kaktus Towers by BIG embody the fusion of design innovation, cost efficiency, and social intent. Their twisted geometries create a distinctive identity, while prefabrication technologies enable rapid construction and sustainable practices. With nearly 500 micro-apartments, the towers provide much-needed affordable housing while cultivating community through shared spaces and green amenities. As Copenhagen continues to grapple with urban density, the Kaktus Towers demonstrate how architecture can rethink not just buildings, but the way people live together.
Construction Costs and Specifications
Element | Specification Details |
Height | ~80 meters (tall tower), ~60 meters (short tower) |
Total Floor Area | ~26,100 m² (280,940 ft²) |
Number of Apartments | 495 micro-apartments (~30 m² each) |
Structural System | Repeated skewed slabs with central circulation cores |
Façade System | Prefabricated balcony and panel modules |
Bathrooms | Prefabricated trapezoidal pods by Green Box A/S |
Amenities | Rooftop park, café, outdoor kitchens, laundry, gyms, party rooms |
Podium Level | Elevated public park and ground-level commercial plaza |
Developers | Catella Group, Høpfner A/S |
Architect | Bjarke Ingels Group (BIG) |
Engineer | MOE A/S |
Main Contractor | LM Byg A/S |
Façade Contractor | HSHansen (HansenGroup) |
Prefabrication Partner | Green Box A/S |
Awards | CTBUH Best Tall Building under 100 m (Europe, 2024) |
References
BIG. “Kaktus Towers.” BIG.dk.
ArchDaily. “BIG’s Kaktus Towers Near Completion in Copenhagen.” ArchDaily, 2023.
Danish Architecture Center. “Kaktus Towers: Prickly Architecture.” DAC.dk.
HSHansen. “Kaktus Towers Project.” HansenGroup.
Green Box Denmark. “The Kaktus Towers.” GreenBoxDenmark.com.
Facades+ “BIG Alternates Balcony Types to Form the Jagged Illusory Kaktus Towers in Copenhagen.” FacadesPlus.
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