Bois-Colombes Aquatic Centre

Client: City of Bois-Colombes (92)
Programme: Renovation of the aquatic centre

Construction value: €4,300,000 excl. tax
Competition winner: 2021

Delivery: 2023

Project team:
Architect: COSTE Architectures

PRESTALIS: Operator

ARTELIA: Lead engineering consultant

ENGIE Solutions

TUAL: MEP engineering

ETAMINE: HQE consultant

1 — Construction of an outdoor leisure pool

The design study for the outdoor leisure pool is based on a thorough understanding of needs and existing conditions, in compliance with the master plan governing the pool layout (with the required dimensions and depths).

– Connection with the existing indoor pool: the bather's passage from the indoor pool to the outdoor pool is provided through a water connection, fitted at the foot of the façade with a passage device using PVC strip curtains to limit cold-air infiltration from the outside to the inside.

When the outdoor pool is closed, a sliding shutter system in the lowered position down to the pool floor prevents access from outside.

An indoor walkway and an outdoor walkway provide unrestricted circulation around the perimeter of both pools.

– Tiled pool: the outdoor pool is finished in tiled cladding to maintain continuity with the indoor pool, which is also tiled. This ensures a consistent visual experience for bathers.

– Thermal cover: the outdoor pool is fitted with a thermal cover, which reduces energy consumption (limiting losses through evaporation and maintaining the required water temperature).

Installing the outdoor pool brings changes to the surrounding outdoor spaces. The area immediately around the pool is dedicated to mineral surfaces. Between mineral and planted areas, an embankment marks the physical separation, made up of rockwork and quality planting, with a foot-bath at the access point.

No tall planting is foreseen around the pool, in order to avoid issues with leaves falling into the water and the related maintenance burden, which would be a nuisance for both the public and the operator.

The existing Ginkgo Biloba tree, of high heritage value, deserves particular attention.

For the outdoor landscaping of the aquatic centre, it is important to know that this is a tree with strong roots — though primarily a tap-root growing vertically into the ground.

We have chosen to relocate the tree during its winter dormancy period, away from the outdoor pool. A large planting pit will be prepared for replanting. The tree can then continue to grow without disturbing operations (no foliage on mineral surfaces or in the pool).

2 — Separation of flows between dry-fitness and wet wellness users

Particular attention has been paid to use and operations.

The flows of dry-shod and bare-foot users must not cross. From an analysis of the existing facility, available areas and the possibility of an extension at the south-west corner of the building, the project orientation was set.

The decision was taken to bring together the wellness and fitness changing rooms on the upper floor. To optimise the changing-room areas, a shared zone is created while respecting the forward-flow principle for bare-foot users.

From the upper-floor changing rooms, users heading to the wet wellness area will take the upgraded staircase, finished in barefoot-suitable tiles, doubled with a lift for people with reduced mobility.

On the first floor, an offer of toilets and showers allows the dry-fitness users to make use of these on the first-floor "sports circuit".

On the ground floor, for wet wellness users, the shower area is enlarged and thoroughly refurbished to provide a clean and pleasant space before the wellness experience.

This flow organisation also showcases the treatment area, which has direct access from the entrance hall on the same level, giving it strong visibility.

3 — Modernisation of the cabin and locker area for the general public

The changing-room area has been entirely rethought in its operation. The reception of the area takes place through a shoe-removal zone, showcased by a beauty area and provision of benches. The current double-entry cabins are replaced by single-entry cabins, reflecting up-to-date use of the space. Two PRM cabins and one family cabin are provided. The existing baby area is retained.

Across the new changing-room offer of the aquatic centre, the number of cabins and lockers is increased in line with the brief.

Floor, wall and ceiling finishes are entirely renewed to suit the new uses (slip resistance, wall protection, acoustic treatment) and to enhance the spaces.

4 — Refurbishment of the wet wellness area: jacuzzi – sauna – hammam

The current wet wellness offer has been analysed. Based on our diagnosis of contemporary uses for this type of space, we plan to thoroughly modernise it.

We propose an outdoor wellness journey for clients. This experience is unique and brings something new to the aquatic centre.

This "Finnish-style" circuit is set on the private outdoor wooden terrace: sauna – sensory shower – Kneipp circuit – pebble-river walk.

This outdoor arrangement causes no disturbance to neighbours. An intimate cocoon is created around the perimeter through planting troughs and plantings along the boundary wall.

Indoors, the existing and ageing jacuzzi is removed, as is the indoor sauna. The hammam, in good condition, is retained.

The sauna alcove is repurposed as storage, addressing a major shortage of storage around the pool decks. This frees up space.

The deck area between the foot-bath and the wellness pool is reclad in timber walls and ceiling with an insulating underlay. The new aesthetic of this wellness approach adds value to the project.

5 — Roof-terrace extension

The current building has a generous south-facing terrace. The new volume created allows for a complementary fitness offer split into two rooms.

The connection with the two-level entrance hall is provided by laying out — in front of these rooms, on the available space — a relaxation area opening onto a wooden-decked terrace, an indoor-outdoor relaxation link for users.

This extension is built with a timber frame to ensure constructive lightness when adding a level on top of the existing building.

The existing generously sized roof fascia is preserved. The extension slips beneath it.

The south façade is treated with horizontal "band" openings at a sill height of 1.5 m over the volume's height.

The façade material is treated in continuity with the existing façades, in clip-fixed stone.

A vertical sense is created by the introduction of vertical screens, providing long-lasting solar protection.

Acoustic management from inside to outside is carefully addressed through the choice of façade materials, so that these spaces generate no nuisance for the neighbourhood.

On the upper floor, a fitness reception area is created within the existing volume. It benefits from the appeal and natural light of the existing central skylight.

Group classes remain in the existing room, which is divided in two to allow different activities at the same time. A lounge-office is provided for personalised exchanges between coaches and athletes.

6 — Cleaning and refurbishment of all building façades

The existing façade materials fall into two distinct categories: clip-fixed stone and a light-beige render facing the streets, in response to the architecture of the surrounding buildings, while on the pool-deck and plant-room sides the chosen cladding is grey metal.

For the stone-clad and rendered façades, a façade refurbishment is programmed during the works, including cleaning. The aim is to restore the building's lustre and to integrate the dual extension on the roof terrace and at the south-west corner of the building.

The new built volumes respect the existing materials by using clip-fixed stone in the same tone.

For the metal-clad façades, these are found to be in good condition and will not require intervention during the works phase.