In Milan’s Porta Nuova district, two verdant towers rise above the skyline—not as symbols of sustainability, but as living systems of architectural and ecological integration. Stefano Boeri Architetti designed the Vertical Forest (Bosco Verticale), redefining high-rise living through a radical embrace of biodiversity, positioning vegetation not as ornament but as structure and inhabitant. As explored in the recently published book Bosco Verticale: Morphology of a Vertical Forest, the project is more than a case study—it’s a manifesto for a new architectural paradigm, one in which urbanism and nature are not opposites, but coauthors of the future city.
Milan’s Vertical Forest Technical Information
- Architects1-11: Stefano Boeri Architetti
- Location: Porta Nuova, Milan, Italy
- Area: 40,000 m2 | 430,500 Sq. Ft.
- Project Year: 2007 – 2014
- Photographs: © Boeri Studio, Photographs by Giovanni Nardi, Dimitar Harizanov, Paolo Rosselli, Laura Cionci
The Vertical Forest is a model for a sustainable residential building, a project for metropolitan reforestation that contributes to the regeneration of the environment and urban biodiversity without the implication of expanding the city upon the territory.
– Stefano Boeri 12
Milan’s Vertical Forest Photographs
Replacing Symbols with Systems
In architectural discourse, buildings are often burdened with the role of symbolism. We ask them to represent ideologies, national identities, even personal ambitions. Yet the Vertical Forest in Milan, designed by Stefano Boeri Architetti, proposes a different ambition that is less about symbol and more about system. It seeks not to stand as a monument but to model a new way of living rooted in coexistence across species and time.
The project’s theoretical underpinning deliberately pivots away from the exhausted rhetoric of “sustainability,” offering instead “biodiversity” as a more actionable and biologically grounded concept. The distinction is not semantic—it suggests a reorientation of priorities. Whereas sustainability is often anthropocentric, measured by human-centric metrics like energy performance and carbon footprint, biodiversity demands an architectural response to the entanglement of species and their habitats. In this sense, the Vertical Forest is not merely an environmentally responsible tower but a provocation toward a new architectural paradigm.
Design Intent and Typological Innovation
At the core of the Vertical Forest lies a provocative typological redefinition: a high-rise conceived not as an abstract machine for living, but as a living ecosystem. The project consists of two residential towers, 80 and 112 meters tall, populated by over 900 trees, 5,000 shrubs, and 11,000 perennial plants. These elements are not decorative but structurally and conceptually central to the project.
The architectural ambition is to recreate, in vertical format, the complexity and variability of a woodland ecosystem. This is not merely metaphorical: the vegetation is carefully distributed based on solar exposure, altitude, and microclimate considerations, creating differentiated vertical ecologies. The design rejects the flattening uniformity often found in high-rise developments, proposing a living façade in constant flux instead.
The project programatically expands the role of the domestic balcony. No longer just a marginal exterior space, the balcony becomes a micro-garden, a site for domestic interaction with the natural world. This domestic-natural threshold is deeply architectural. It demands careful calibration of dimensions, load-bearing systems, and environmental control.
Furthermore, the Vertical Forest introduces a new occupant: the non-human. Birds, insects, and microorganisms are not intruders here—they are co-residents. Architecture, in this model, is not anthropocentric. It is relational.
Milan’s Vertical Forest Materiality
Technically, integrating vegetation at this scale required extensive innovation. The façade system incorporates custom-designed planters that are structurally bonded to cantilevered balconies. These planters are equipped with automated irrigation and drainage systems, ensuring the plants’ survival and minimizing maintenance demands.
The material palette is sober and intentionally recessive, allowing the vegetation to define the building’s appearance. Reinforced concrete and high-performance glazing form the base infrastructure, while steel supports accommodate plant containers. Here, materiality is subordinate to life. The building’s expressive potential lies in its ability to host dynamic, seasonal transformation.
From within, the spatial experience is both ordinary and radical. Interior spaces are standard in configuration, yet the constant presence of trees at eye level transforms the perception of urban dwelling. Residents are immersed in a filtered lightscape, where branches rather than neighboring structures cast shadows. The ever-changing interior and exterior relationship between architecture and nature becomes an architectural quality.
Moreover, a team of specialized arborists maintains the building, who rappel from the rooftop to tend to the trees. This maintenance is not ancillary but part of the building’s operational logic. The architecture extends beyond static form to include ongoing ecological care as a fundamental element.
Broader Contextual Significance and Legacy
Since its completion, the Vertical Forest has attracted international attention, not just as a compelling image, but as a new urban prototype. Its replication in cities like Nanjing, Utrecht, and Paris signals the emergence of an alternative model of urbanization that considers vegetal life not as landscape but as architecture.
However, the broader significance of the Vertical Forest lies in its challenge to architecture’s disciplinary boundaries. It invites collaboration with botanists, ecologists, agronomists, and environmental engineers, expanding the scope of architectural authorship. The architect is no longer the sole creator but a coordinator of living systems.
By proposing biodiversity as a new metric for urban quality, the Vertical Forest calls into question many of the assumptions of contemporary urban design. It resists object-building and its preoccupation with form, reorienting architecture toward ecological integration and biological interdependence.
If there is symbolism here, it is not in the building’s image but in its ambition to seed a different kind of city—one that acknowledges that the future of architecture may well depend on how effectively it can become a host.
Milan’s Vertical Forest Plans
Milan’s Vertical Forest Image Gallery
About Stefano Boeri Architetti
Stefano Boeri Architetti, established in 1993 and headquartered in Milan with additional offices in Shanghai and Tirana, is an international architectural practice renowned for integrating biodiversity and sustainable design into urban environments. The firm’s diverse portfolio spans architecture, urban planning, and interior design, consistently emphasizing the symbiotic relationship between nature and the built environment. Their groundbreaking project, the Vertical Forest (Bosco Verticale) in Milan, exemplifies their commitment to innovative solutions that promote urban reforestation and ecological balance.
Credits and Additional Notes
- Design Team: Stefano Boeri (Lead Architect), Gianandrea Barreca, Giovanni La Varra
- Client: Hines Italia SGR S.p.A.
- Structural Engineering: Arup
- Botanical Consulting: Laura Gatti (Agronomist and Landscape Consultant)
- Façade Engineering: Arup and Milan Ingegneria
- General Contractor: ZH General Construction Company
- Landscape Maintenance: Boeri Studio in collaboration with specialized arborists
- Height: Tower D: 80 meters (19 floors); Tower E: 112 meters (27 floors)
- Greenery: 900+ Trees (3, 6, and 9 meters tall); 5,000+ Shrubs; 11,000+ Perennials and ground cover plants
- Residences: 113 Apartments
- LEED Certification: Gold
- Bosco Verticale: Morphology of a Vertical Forest by Stefano Boeri Architetti
