Fresh water is valuable, so maximising the use of seawater is important. Ensuring that the resulting piece of architecture is non culture-specific is a possible way for it to get accepted.
The sea is a resource shared by all, so interiorising it and celebrating it as a unifying factor could lead to greater affinity in the society.
Appoach from the beach: site remediation and the ancient tower
The entrance canopy is a spectacle of the play of light and water - a taster of the experiences within the building. The "pierre banchée" construction process is proposed for the design. Developed by Fernand Pouillon (1912-1986), it uses stone as permanent shuttering to concrete. This technique is employed in the majority of the post-war buildings in the Old Port area of Marseille.
Marseille is a Mediterranean port city with a North-South divide. Historically a city of sugar, oil and tobacco refineries, it is gradually reinventing itself into a city of science and leisure.
Limestone coves on the South coast known as ‘les Calanques’ were turned into a national park in 2012 but are not easily accessible.
Numerous beaches and the Corniche, a coastal promenade, dubbed the “6km of happiness“ are offered as an alternative.
With the port dominating the northern coastline, there is asymmetry in the provision of leisure facilities. Investment is needed into those leisure zones that are accessible to the majority of the population.
The closest beach to the city centre, Les Catalans, has a unique microclimate because of the surrounding topography. Historically a site of a hospital, a home to a Catalan fishermen community, the area also has a rich bathing history, as can be seen in the numerous ‘scars’ left on the rocks. Developers have always been eager to capitalise on the uniqueness of this location. However, the city is reclaiming the land - the beach is now public, and a new spa resort proposal has been scrapped thanks to protestors who instead want a pool and more public space.
1:200 Proposal Model
The placement of the proposal negotiates the north-south divide in the city. It addresses the lack of public space and stretches the boundary of the Euromediterranee regeneration project across the bay, bringing business to the numerous wellness facilities in the local area by creating a new destination on the Corniche.
The thesis idea can be metaphorically compared to one Marseille speciality, - ‘Bouillabaisse‘, a stew made from different varieties of fish.
Thalassotherapy (sea therapy) relies on medicinal properties of seawater. It is believed that at 34 C pores dilute and are more open to benefitial mineral exchange with seawater. Seawater is drawn from 400m away from the coast and is renewed daily. It is envisaged that the facility will be funded by the city, with subsidised entry costs for the local residents. The focus is on allowing water to stimulate the different senses, including the sense of gravity. Immersion in water results in buoyancy which is calming and non culture-specific. Not only are people stripped of their social masks, they are also liberated from the worries of their everyday lives and are more open to interaction and mutual acceptance.
The site plan above highlights the lack of public space in the area, where it is said that the sea is a replacement for the parks. The drawing above also maps the age of buildings by century and plot uses related to well-being. La Notre Dame de la Garde [bottom right corner], the iconic cathedral, is visible from the site. It features viewing terraces known as ‘the balconies’ that are well-loved by both locals and tourists alike.
The building massing is additive to express the idea of uniting different people in one facility. The design is composed of programmed vessels on a mediating surface. Clearly distinguishable from the outside, their boundaries merge inside, forming interconnected spaces. The experience culminates in the main thalassotherapy pool (“Bouillabaisse“), but bathers are free to personalise their visit. The cleansing block has elemental facilities that can be used to perform various bathing rituals. The design encourages social interaction and the invention of new rituals.
The design enhances the vista for the surrounding streets, provides ramped access to the beach as well as a new city “balcony“, addressing the identified lack of public space. It brings a taste of “les Calanques” to this city centre site. The ambition was to create an elemental structure, free from complex symbology to ensure inclusiveness.
1:500 Site Model with Proposal
Cross-section through the proposal: stepping down from the city to the sea
Main Level Plan
The cleansing space is a chance to perform the bathing rituals specific to your culture using simple elements: - fresh and sea water at different temperatures, hot and cold baths as well as private showers and a steam room.
The culmination of the building is the main thalassotherapy pool. It is a human made cave where people of different backgrounds mingle and enjoy the pleasure of buoyancy in warm seawater.
50mm limestone permanent shuttering to concrete;
200mm waterproof concrete;
250mm Foamglas insulation;
500mm void / services / connecting beams with an integrated thermal break;
150mm waterproof concrete - vertical board imprints;
25mm ceramic tile finish in lower part of the wall.
Narrow openings in the pool wall let the subtle diffused and reflected light into the space. Their reflections animate the surface of the water and also metaphorically reference pine tree groves.
The void of the wall not only accommodates services, but also acts as an air plenum itself. Air is encouraged to rise up towards the MVHR extraction grille at the top. This process is solar-assisted when possible. With the pool hall temperature requirement of 28 C, overheating is not expected to be a problem, and in the absence of a MVHR system heating in the pool hall would have been required even in summer.
Basement Plan
Upper Level Plan
Reception / Soap Shop
Changing Room
Yoga Studio. Top lighting is maximised for privacy. Framed views of the city and the sea are provided as a point of reference.
Hot and Cold Plunge Pools
Steam Room
Tea Lounge
Lounge: Drinking Fountain
Lounge: Entrance to the Main Pool Hall
Pool Hall as a receptacle for the sunset
Cavelet
The design enhances the pleasant microclimate of the site through the use of green roof and by providing shaded outdoor spaces. The massing of the building protects those using the sunbathing terrace from the strong NW winds.
Les Calanques
The site has little overshadowing and is protected from the strong northerly winds by the Pharo penninsula. It is still exposed to NW winds, which often makes it impossible to linger after bathing in the waves. Having a west-facing orientation, the beach is a receptacle for the sunset. Street noise is attenuated by the change in level. The latter is resolved by a simple metal staircase, which limits accessibility.
The site as existing
In addition to a varied cityscape of residential developments, the site is adjacent to military barracks, that are surrounded by a tall wall. Among the main features of the site is a limestone rock and an ancient tower, which is the oldest building the area. While the strategy is to remediate the site, it was important to preserve the tower for temporal continuity.
The building uses a concept of a “geode“ - a cavity in rock lined with crystals. Some spaces are to be discovered within walls - e.g. the little “caves“ in the main pool. The materials used for the proposal allude to the pine tree groves and the limestone coves of “les Calanques.”
“Dolia” - storage vessels used in the Roman dockhouse in the Old Port are some of the few ancient relics that remain in Marseille . These have inspired me to take on an elemental approach to the “cleansing vessel” in the programme. Privacy is important in a bathhouse, so references were made to traditional forts, which offer protective environments within monolithic shells. And just like a shell the building is rough on the outside and smooth inside.
Conceptual Model of the Proposal: building + public square + sea
1:200 Massing Model of the Proposal
Ground-source heat pump is immersed into the sea to provide heating of pool water The heat pump runs on electricity which mainly comes from nuclear. Resulting from an in-depth investigation, the proposed system makes a 98.5% reduction in carbon emissions over a conventional gas boiler. It does require a water-to-water heat exchanger and an insulated storage tank of an equivalent volume to the pool.
Fresh water is a scarce resource so its use is minimised. Seawater is delivered through a 400m long sea pipe. Litter is captured by the system, which helps to purify the sea. Used seawater is discharged at 6 am daily through fountain nozzles embeded into the rim of the external pool. Fresh water use is minimised in the building with the help of grey water recycling and by providing tapped seawater.
Sea view is maximised with an “infinity“ edge detail. The large 90-degree window facing the sea is securely fixed to resist lateral loads. It features a frameless construction. It is an uninterupted laminated glass pane that can be delivered to site by boat. The ambition is to provide top lighting with beautiful water refraction patterns spilling out into the surfaces below. This is accomplished by using acrylic glass skylights in the roof of the lounge and forming a 400mm deep decorative pool in them. To achieve a coherent ceiling finish and yet to optimise the structure of the roof, timber slats are attached to the soffit, concealing the varying depths of concrete slabs.
To minimise heat losses, the hottest spaces in the building are positioned centrally within the plan. The top of the hottest space, the steam room, has a pyramidal shape as it reduces the volume of the space without affecting the floor area. Ventilation rates are increased to deal with humidity, and to avoid wasting heat, mechanical ventilation with heat recovery is used. Waste heat from the plantroom, laundry and kitchen is redistributed throughout the building by two MVHR systems. The pool hall MVHR is in operation throughout the year, but the other one is seasonal.
The building admits the environmental influences that are desirable and exludes the undesirable ones. Summer sun is blocked by deep reveals. West-facing windows are maximised in spaces with increased heating loads. A west-facing solar collector doubles up as a thermal transition zone between the interior and the seaside.
Courtyards are provided for light and ventilation. There is a variety of thermal zones and instead of being in complete control over conditions, bathers are encouraged to find the space they feel comfortable in.
The less sensitive lounge space is adjacent to the road, acting as a “buffer zone“ and reducing traffic noise in the primary spaces. There are less windows facing the street than those exposed to the sea view and the sound of the waves.
The structure is simple and tectonically clear, with the forces being visually taken to the ground. The cellular structure of the basement bears the load of the concrete slabs above. A green roof sits on the concrete slabs as well, which in addition to the walls, is supported by structure surrounding the courtyards. The roofs of the blocks have a lighter construction and are supported by glulam beams.
The proposal also features a dramatic large opening in the pool hall. This is formed by two cantilevers that are joined to the rigid structure of the diaphragm cube. The building sits on limestone rocks, but some foundations are underwater and experience a lateral load from the waves. A diaphragm waterproof construction system was chosen as a solution, as four walls produce a stable structure without the need for further bracing, so that the roof structure could be optimised. Glulam beams are proposed as they are lighter and are a reference to the pine tree groves of “les Calanques“.
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Seawater Bathhouse, Marseilles (Thesis, 2013)
Sea Refinery is a thalassotherapy bathhouse on an urban beach in Marseille. The city was the European Capital of Culture at the time (2013). Marseille's culture is said to be alive in its people, who are famous for their diverse roots. The thesis is that by providing a variety of conditions for interacting with seawater one can satisfy the ritual needs of a wide mix of people, allow for the expression of culture and create a unique and unifying experiential journey.
