GENEVA–PAV–ARCHIBORETUM: IT WAS ALMOST LIKE A DREAM…

There are projects that make you want to believe that cities can still be ambitious. And then there’s Geneva...

Amidst the vast Praille-Acacias-Vernets (PAV) urban development project, one scheme briefly offered a glimpse of what a 21st-century metropolis might look like: Vincent Callebaut and his spectacular Archiboretum. An idea that was almost scandalous in the local architectural landscape: a city that is beautiful, eco-friendly and visionary.

Fortunately, the Geneva authorities are keeping a close eye on things. We almost dared to dream… but not for too long.

In Geneva, we narrowly avoided a serious incident: a magnificent architectural project. Yes, these things do happen… by accident.

As part of the major PAV urban project, the visionary architect Vincent Callebaut had conceived something unbearably bold: ARCHIBORETUM.

Two wooden towers, linked by a suspended park, covered in vegetation, generating their own energy, incorporating urban agriculture, biodiversity and environmental technologies. In short: a sublime project for a city of the future...
Horror!!!
For Geneva is a serious city; here, architecture must remain a cold administrative activity, devoid of passion, taste or joy... Joy? Calvin always forbade the slightest display of ostentatious pleasure, and Geneva’s leaders are indeed his worthy heirs...

Now, let’s be honest, over the last 35 years we have seen a few very rare magnificent buildings go up, but with interminable procedures and particularly confidential political arrangements – that is Geneva too.

By Alain Farrugia

ARCHIBORETUM, A PROJECT THAT RESEMBLED A CITY OF THE FUTURE

On paper, Archiboretum had everything it needed to become one of Europe’s most iconic urban projects

Two twin towers of solid timber, linked by a suspended public SkyPark, forming a sort of inhabited vertical forest. A complete neighbourhood stacked vertically: housing, offices, a hotel, shops, cultural spaces. In total, 90,000 m² of mixed-use space, with over 600 homes and 600 jobs.

But the project went far beyond a mere architectural feat:

Cross-laminated timber (CLT) structure sourced from certified local forests
Solar and photovoltaic facades generating electricity and hot water.
Geothermal energy and biomass to provide heating and cooling.
Complete water recovery with phytoremediation and reuse.
Urban agriculture, greenhouses, aquaponics and permaculture integrated into the project.
Biodiversity corridors with beehives, habitats for insects and bats.

And, an almost audacious detail: 45% of the site was dedicated to a metropolitan park, combining an urban forest, community vegetable gardens and aquaponics ponds.

In short, a vision: a city that generates its own energy, fosters biodiversity and produces some of its own food.

A LIVELY CITY

Urban planning that breathed

Archiboretum was not just a spectacular building; it was a philosophy.

The central idea was simple: to transform an urban block into a living ecosystem. The towers were designed like gigantic trees: a central trunk, branches, green terraces, and biomimetic architecture optimising light, ventilation and thermal comfort.

Instead of the traditional logic of the dormitory neighbourhood, the project proposed a complete vertical neighbourhood, combining housing, work, culture and public spaces.

An urban design that breathes, generates energy and brings nature back into the city.

In short, an almost dangerous idea.

GENEVA, WORLD CAPITAL OF THE RECTANGULAR BLOCK

For in Geneva, architectural innovation follows a simple rule:

Never exceed the level of audacity of an underground car park.

In the gigantic Praille-Acacias-Vernets urban project, intended to redesign an entire section of the city, the dominant aesthetic seems to draw inspiration from an architectural heritage of infinite richness:

The French suburbs of the 1960s
Soviet residential estates from the Brezhnev era.

A style instantly recognisable:

Rectangles
Repetitive façades
Standardised concrete
Perfectly aligned windows to avoid any visual excitement.

The aim is clear: never to provoke any emotion… It’s a total fail – it makes us feel sick… Yuck…

THE GREAT URBAN IDEAL: THE OPTIMISED RABBIT HUT

For Geneva’s urban planning pursues a noble mission:

To cram as many human beings as possible into the smallest possible space.

Beauty comes at a price.
Imagination is risky.
Originality upsets the committees.

So we ‘optimise’:

Optimised flats.
Optimised façades.
Optimised budgets.
Optimised car parks… so optimised that they’re scrapped…

And above all, optimised slaves in perfectly standardised rabbit hutches.

All accompanied by an environmental rhetoric so green it would make a petrochemical waste tip look like a nature reserve, because in Geneva you can build perfectly ugly and dreary concrete blocks whilst explaining that you’re saving the planet.

ARCHIBORETUM’S ULTIMATE CRIME: BEING BEAUTIFUL!

In this context, Archiboretum committed a major strategic error within Geneva’s administrative ecosystem:

It was beautiful and spectacular

Worse still:

It was daring
It was iconic
It was ambitious
It could have become an international symbol.

In other words, an unacceptable risk.

For Geneva has a very strong urban tradition: to carefully avoid any architecture that might become famous.

Imagine for a moment the scandal:

Tourists taking photos of a building,
Architecture magazines writing about Geneva,
Students coming to study an innovative urban project.

Worse still, an architectural project likely to make a visitor say: ‘Look, this city still dares to invent something.’

Chaos!!!

A WEALTHY CITY THAT BUILDS LIKE A TIRED SUBURB

The Geneva paradox remains fascinating.

The city is one of the richest in the world. It is home to international organisations, research centres and multinationals. It could become a global laboratory for sustainable cities.

But when it comes to building… it produces, almost religiously, the most bland urban planning on the continent.

Urban planning that seems guided by a fundamental principle: Above all, do not create anything interesting, let alone beautiful.

THE TRIUMPH OF PUSILLANIMITY

The word is harsh but perfectly apt: timidity.

The fear of daring.
The fear of displeasing.
The fear of stepping outside the administrative mould.

So we choose the safest option: the administratively standardised concrete block

Always the block.
Yet again, the block.
The glorious rectangular block.

That timeless monument to the bureaucratic imagination.

WE ALMOST DREAMED

With Archiboretum, Geneva could have shown something different:

Spectacular eco-friendly architecture
A city capable of innovation
A European metropolis looking to the future.

But rest assured, the system works.

The committees are keeping watch.
The regulations provide protection.
Dreams remain safely tucked away in the files of visionary architects.

And the people of Geneva will be able to continue admiring the best their city has to offer: magnificent rows of perfectly uniform cubes.

Progress, but without the risks... And above all, without the dreams!

ARCHIBORETUM BY VINCENT CALLEBAUT

Read and dream of what we could have had in Geneva—something fabulously beautiful and innovative....

ARCHIBORETUM, TWIN WOODEN MIXED-USE TOWERS, GENEVA, SWITZERLAND

By architect Vincent Callebaut

An urban, ecological and social manifesto for a resilient Geneva territory, by Vincent Callebaut Architectures, Paris

Between the historic heart and the new city, on a plateau overlooking the Rhône, Archiboretum unfolds as an inhabited ecosystem where nature and culture converge. A true urban catalyst, this project is part of the Canton of Geneva’s strategy for carbon neutrality and the qualitative densification of metropolitan centers. Its bio-inspired design and circular energy approach meet the most advanced requirements of the SNBS, Minergie Eco and 2000 Watts labels, combining environmental excellence, social inclusion and structural innovation.

Symbolized by two twin mixed-use wooden towers connected by a skypark and its observation bridge open to the public, Archiboretum’s architectures fuse housing, work, urban biodiversity and local resources into a coherent and regenerative whole.

PILLAR 1 – POROUS AND REVERSIBLE URBAN DESIGN

Archiboretum redevelops a strategic territory by creating physical, ecological and social permeabilities.

30% of the site is freed up for large public and pedestrian squares linking the main road to the existing residential fabric, promoting soft mobility and inclusion.
45% of the plot accommodates a metropolitan park, combining urban forest, collective market gardening and aquaponic ponds that help manage rainwater naturally.
25% of the basements are dedicated to an active gallery housing craft businesses and local services, naturally lit by vegetated patios.

This landscape and functional strategy aligns with Geneva’s planning policy, fostering the creation of open, green and resilient centralities.

PILLAR 2 – MIXED PROGRAMMING AND ORGANIC IDENTITY

The project offers a mixed vertical neighborhood, balancing residential, productive and cultural functions to strengthen urban cohesion. Over 600 homes and 600 jobs will be created.

90,000 m² of floor space combines housing, offices, a hotel, shops and a performance hall in a fluid and convivial verticality.
Generous 3.20m ceiling heights combined with double-floor systems ensure comfort, flexibility and reversibility of use.
The architectural morphology draws on biomimicry – a central trunk with radial branches, spiral cascades, a diamond-point exoskeleton – to optimize solar gain, natural ventilation and ergonomics.

This programmatic diversity guarantees sustainable energy and social balance, supported by soft mobility and shared space management.

PILLAR 3 – HYBRID STRUCTURE AND CIRCULAR MATERIALS

The urban block expresses the convergence of low-carbon technologies and Swiss construction artistry.

Main structure in locally sourced, PEFC-certified cross-laminated timber (CLT), coupled with an optimized prestressed concrete base to limit CO₂ emissions.
Incorporation of recyclable high-performance steels, reducing the building’s overall mass.
Bio-based facades and insulation, 50% of which are Cradle to Cradle (C2C) certified, promoting the circular economy in French-speaking Switzerland.
Selective deconstruction of existing small buildings feeds the complete upcycling process, following a zero-waste construction site approach.

This constructive approach gives the entire project total life-cycle traceability, in line with SméO and LCA (Life Cycle Assessment) methodologies.

PILLAR 4 – URBAN BIODIVERSITY AND TREE-LIKE ARCHITECTURE

Archiboretum embodies the idea of a forest-city where each building functions as a micro-biotope.

Multi-level vegetation: skypark on roofs, balconies, terraces, loggias and patios intensively planted to strengthen the urban ecological network both horizontally and vertically.
Creation of wildlife habitats: beehives, insect hotels and bat shelters.
Integrated water cycle management: rainwater harvesting, phytoremediation and greywater reuse as part of a 100% Water Footprint approach.
Establishment of an educational farm and greenhouses dedicated to urban permaculture, promoting local agriculture and the transmission of ecological knowledge.

These immersive features contribute to the Swiss “Biodiversity” label, placing nature back at the heart of the urban process.

PILLAR 5 – ENERGY SELF-SUFFICIENCY AND POSITIVE TERRITORY

Archiboretum aims for positive energy balance performance, aligning with the roadmap of the cantonal 2000 Watts Society program.

Photovoltaic and solar thermal roofs and facades produce electricity and domestic hot water.
Dense network of geothermal probes ensuring passive heating and cooling.
Collective biomass boiler and inter-building energy loops adjusted to seasonal needs.
Recovery of organic waste into local biogas, supported by SméO modeling and full building life-cycle analysis.

The entire project is part of a TEGPOS strategy (Positive Energy Global Territory), combining buildings, public space and responsible mobility in a closed energy loop.

CONCLUSION

Archiboretum asserts itself as a manifesto for a living Geneva, reconciling metropolitan density, active biodiversity and energy autonomy. Through its local roots, Swiss technical governance and climate adaptation capacity, the project meets the highest sustainability requirements set by the Canton of Geneva. It embodies a new generation of regenerative urbanism, combining land-use economy, precision engineering and the poetry of materials to make the city an organism that breathes, produces and shares.

SUMMARY: ARCHIBORETUM, Geneva, Switzerland

Located between the historic center and the new city, Archiboretum is set on a plateau overlooking the Rhône as an urban manifesto blending architecture, vegetation and energy. Designed by the Paris-based firm Vincent Callebaut Architectures, the project weaves a sustainable link between housing, work and biodiversity by reinterpreting the Geneva block as a living ecosystem.

Its twin mixed-use wooden towers, connected by a skypark and its observation platforms open to the public, bring together housing, offices, a hotel, shops and culture in an organic verticality inspired by biomimicry. 45% of the site becomes a public park combining urban forest, market gardening and aquaponic ponds that harvest rainwater, while the mezzanines host an open, vegetated active gallery dedicated to local crafts.

The architecture combines PEFC cross-laminated timber, prestressed concrete and C2C bio-based materials in a circular approach, targeting the Swiss SNBS, Minergie Eco and 2000 Watts standards.

Powered by solar, geothermal and local biomass, Archiboretum achieves energy self-sufficiency and is part of the cantonal TEGPOS strategy (Positive Energy Global Territory).

Archiboretum embodies a post-carbon, regenerative neighborhood prototype: a symbiosis of land-use economy, Swiss engineering, constructive sobriety and plant poetry in the service of a resilient and visionary Canton of Geneva.

To learn more about Vincent Callebaut Architecture