ADAo architectes sàrl - Lacustrine Installations, the circular pontoon for a dynamic context
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Lacustrine Installations, the circular pontoon for a dynamic context

ADAo architectes sàrl

Sport&Leisure  /  Completed
ADAo architectes sàrl
In response to the recent needs for open water bathing expressed by the population, major Swiss cities have, for several years, been developing free and natural spaces dedicated to this activity. In Geneva, the refurbishment of the Quai de Cologny is part of this dynamic context, creating on the one hand new access points to the water for the general public and on the other hand natural areas comprising reed beds and aquatic flora. Thus, a sequence of alternating leisure and nature areas has been developed along the embankment.
The circular pontoon, highlight of this lacustrine partition, is made up of two rings between which a curved wave-shaped bench is inset. Tangent to the shore, this 800 m2 and 40-metre diameter platform allows bathers to swim either within the circle, in a sheltered area away from the waves, or outside in open water.
In view of the size and exceptional beauty of Geneva's bay landscape, it was paramount for us to create a structure based on simple shapes, with a strong and assertive aesthetics. The circle, an infinite line, evokes the whirlpool, the ripple, the impact of a drop on the lake. Inspired by its natural environment, the pontoon’s pure geometric shape is therefore in motion, in a moving landscape.
Circular or spiral figures have always fascinated artists and architects, particularly in water-related contexts, as testified by the many examples of pontoons, pools and works of land art created throughout the world. The circle is a figure that radiates and gathers in a movement both centripetal and centrifugal. As it evokes the idea of community, we found this shape to be particularly suited to a structure intended for the general public.
The top side of the pontoon is clad with an oak "casing" whose relief engages with the horizontal plane of the lake and the gentle undulations of the Jura. The rolling surface is based on the idea of creating a sort of "wooden dune", thereby invoking images of the beach. The "pleated" expanse offers the general public a wide range of possibilities - sitting, lying down, leaning, meeting, etc. The circular shape offers a variety of viewpoints as well as different exposures to sun and wind.
The production of this wooden surface involved 3D modelling the entire pontoon, detailing the beveled geometry and position of each of the 5’000 boards that make up the platform. This comprehensive method allowed for an optimal exchange of information between the architects, engineers, timber supplier and the carpenters.
Although solidly anchored into the lake bottom, the pontoon is a "light" construction which gives the appearance of floating on the lake. Resting upon 24 piles driven into the molasse, the circular reinforced concrete platform creates a sort of shield which protects the decking from lake swell. Placed on the concrete slab, the undulating shape of the bench leans against a stainless-steel structure reminiscent of the ribs of an aircraft wing.
As a result of extensive research, Swiss oak was chosen for its traceability, the availability of stocks, of planks, its exceptional durability, the lack of splinters and seepage and its reasonable cost. Easy to maintain, it will acquire a patina and become grey over time, but without compromising its durability. The use of locally sourced wood, in a short supply chain, is a major bias on the client’s part as it is synonymous with a favourable ecological, social and economic outcome both for Geneva and Switzerland in general.


 Commune de Cologny et Etat de Genève / Service du lac de la renaturation des cours d’eau et de la pêche
 3640 mq
 Mariana BARBOSA / Nicolas DEVILLE
 ADAo architectes sàrl
 Groupe Corbat SA, Implenia SA
 Cera SA, Le Collectif sàrl
 CR SA, Gaidon SA, Georges Kunz SA
 Fabio CHIRONI, John MAGNIN, Sandra POINTET, Renaud MARION, ADAo architectes sàrl


In terms of subject matter, architects are generalists whose specialty is searching for ideas, creating concepts and developing projects.
Our works are developed on multiple scales, ranging from small interior design to territorial studies. The fields in which we operate range from housing to conference centres and from public spaces and infrastructures to administrative buildings.
Each project’s unique nature calls for specific and original responses. In order to accurately identify the client’s needs, we work with them to define the design brief and the “project’s project” before translating it into an architectural project.
Finally, in the manner of a watchmaker specialized in “watches with complications”, the experience we have acquired enables us to develop particular skills in the field of “projects with complications”, as demonstrated by the complexity of projects such as the Louis Jeantet Foundation for Medicine or the International Conference Centre Geneva.

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