Text description provided by the architects. The agora
The design of the gymnasium and the square of central Chelles was an opportunity to use an architectural project to address urban issues that have been left aside in past developments. The plot is indeed in a central position between the Park of Remembrance Emile Fouchard, the town hall, the Weczerka high school and the centre for contemporary art «les églises»: a highly heterogeneous environment where all the symbols and powers of the city (the church, State, culture, education and sports) are concentrated.
All these components, in this case, seem more juxtaposed than actually ordered, despite the delicate intervention by Marc Barani and Martin Szekely transforming the two churches into a center of contemporary art.
The aim of this project is to replay this rescheduling, elevating it into the category of an agora. The space, therefore, was in need of a strategic, volumetric insertion and an idea, contributing to the completion of the history and a new perception of the whole.
Urban role of the new building
Based on this observation, we considered the project as an operation of urban reassembly in which the gym and esplanade play the role of articulation. We relied on a detailed analysis of the operation, sequences and the scales of the various components. The orthogonal footprint of the building is parallel to the facades of the high school and the town hall. In this way, it helps to redefine and enhance urban spaces as well as to connect the park to the church through a journey.
These public spaces, the piazza and the new pedestrian street, are drawn in a conventional manner: regular, surrounded and defined by buildings.
An urban object, a «catalyst» of views
Once the volumes were constructed, the challenge of the architectural project has resided in the renewal of the traditional vocabulary of the gym: very often, we deal with an opaque box, blind and deaf to the context in which it occurs.
Here, we had to escape from the imagery related to sports facilities to implement an object which «lets us see» a fragmenting urban kaleidoscope, diffracting and reflecting the image of the surrounding buildings in order to respond with a new, more sensitive vision.
To this end, the facade is composed of two layers, the first (the glass) reflecting and letting in light, and the second (the copper), coloring and magnifying the reflection, providing protection from glass impacts.
While the simple shape and the orthogonal location of the building allows to order spaces, the facades create an ambiguity emptying the building of its materiality, making it disappear. The whole gives an impression of lightness and magic. At night, the game is reversed.
The gym, with its style and footprint, aims to be the symbol of a new vision of the city.
Once the urban strategy and the treatment of the facades were defined, the simplicity of the volumes allowed to turn the spatial organization of the gym into an efficient and functional area.
The technical system used for the envelope is simple: a steel structure, the bottom of the glass facades made of a concrete wall insulated by an indoor copper cladding. This double skin provides an ideal sound insulation. The copper, plated on timber, absorbs noise and reduces resonance in high volume areas such as multisport halls. The realization of this project is also a good example of an eco-construction.
A project based on the logic of eco-construction
Thermal insulation Ranked at the Very High Energy Performance (THPE) level, the building ensures a high level of comfort thanks to the inertia of its insulated concrete walls that contribute to cooling in summer and limited heat loss in winter. It is reinforced by the presence of night ventilation in the spaces. The system used consists of a power plant processing dual-flow air recovering energy from exhaust air. Each façade is equipped with a glazing area of 2.28 m2, STADIP 44.2 «securit» type, on the external side and tempered glass (8 mm), with a 14mm argon heat-resistant blade.
The site is directly connected to the city’s geothermal heat network. A heating programmer prior to space occupancy is also implemented. The heat distribution ensures the needs of hot water and heating the gym, an extension, changing rooms and circulation spaces.
Thirty-two photovoltaic modules with an output of 7360 Watts, or 6600 VA for resale to EDF, have been installed.
Outside, the rainwater recovery system works together with the green roof. It supplies the gymnasium’s sanitary areas and the surrounding greenery.
The building receives natural light through large windows on the curtain wall and roof. It is emphasized by the external presence of a LED light recessed floor. The access points are marked by candelabra. Presence detectors are being used in all interiors, except for the great hall, optimizing power management based on attendance.