480 large trees thirty metres above ground, and ten years of photographs to vouch for them. Milan’s icon proves one rare thing — that it lasts — and leaves another wide open: the ground.
Start with what Bosco Verticale has actually proven. Sizing a structure to carry 480 large trees, 300 smaller ones and thousands of shrubs, cabling them against the wind, organising maintenance by rope-access gardeners: in 2014, nobody had done it at this scale. Ten years later the trees are there, photographed, documented — and that kind of hindsight is a rare commodity. To the objection “how will it age?”, this project offers one of the only long answers planted architecture has.
Then say what it does not prove. Everything is off the ground: not a square metre of open soil, no ecological continuity with the city, a plant palette selected to survive in pots at altitude — a superbly kept hanging garden more than an ecosystem. And its upkeep, around €63/m²/year all in, reserves the model for programmes that can afford it. The public debate it opened — including the widely quoted calculation that the same budget would have planted a forest hundreds of times larger at ground level — deserves to be heard rather than dismissed.
Our reading: Bosco Verticale is a precious case study, provided it is cited for what it demonstrates — technical feasibility and endurance — and not as a general model. Start with the soil; keep the high-altitude feat for sites that offer the living world no other purchase. That order of operations is what this project, in negative, confirms for us.
What we take away
- Ten years of documented hindsight — the strongest available answer to “how will it age?”, best used separately from the question of cost.
- Structural feasibility: plant load, wind, cabling — the know-how exists and is published.
- Real, organised maintenance (rope-access gardeners, co-ownership): the living world has a named caretaker here, still the exception.
What leaves us wondering
- No open soil, no continuity with the urban ground: most biodiversity happens precisely where this project does not go.
- A high, ongoing management cost, which raises a fair question about budget versus actual ecological benefit — the public debate on this point is documented and legitimate.
This project is the work of Boeri Studio. The analytical sketch is by LIBER.ARCHI; original photographs and documents belong to their authors and are best discovered at the source.
View the project — Stefano Boeri Architetti — page du projetLIBER.ARCHI analytical sketch — our reading of the project, not a reproduction.
Guillaume Ciletti
Licensed Architect (HMONP) — Founder of LIBER.ARCHI