Hotel Oceania Lille: A stainless steel swimming pool in the old strongroom
"Bringing together a century-old bank vault with a 316L marine-grade stainless steel water feature: this is the kind of project that defines our profession. Stainless steel is not just our material; it's our way of responding to the history of the places we work in."
The wellness area of the Oceania Hotel Lille — custom-made 316L stainless steel pool in the former vault room
In the heart of Lille, a hotel has made the bold choice of installing its wellness area in a place steeped in history: the former safe deposit box room of a bank, preserved in its architectural integrity. At the center of this banking sanctuary, converted into a wellness sanctuary, a custom-made 316L marine-grade stainless steel pool, designed by Steel and Style, dialogues with the hundreds of patinated brass drawers that constitute the memory of the place.
This achievement illustrates what defines our approach: designing aquatic structures conceived as architectural pieces, capable of fitting into demanding heritage contexts without compromising on technical performance. Here is the story of this project.
Read in 30 seconds
A custom-made 316L marine-grade stainless steel pool integrated into the former bank vault, now a hotel
A technical challenge: lowering modules into a classified basement and integrating an aquatic structure into a constrained volume
A material dialogue between contemporary marine-grade stainless steel and the century-old brass of the preserved vaults
Manufactured entirely in our workshop in Mérignac by our team
Integrated RGB LED lighting that sculpts water reflections on the walls of the old vault room
Summary
Table of Contents
The location — a former bank vault in the heart of Lille
The Oceania Hotel Lille occupies a building whose initial purpose was entirely different. Before welcoming guests, the building housed the services of a historic bank in the Lille metropolitan area. In the basement, behind several-centimeter-thick armored doors, was the safe deposit box room: a long volume punctuated by alcove niches, each containing several dozen secure brass drawers, numbered, installed under recessed lighting.
During the rehabilitation of the building into a hotel, the client made a strong positioning choice: to preserve the entirety of this vault room as an element of the place's identity. The brass drawers, their original locks, the engraved numbers — everything remained in place. It was in this space, steeped in a century of banking history, that the heart of the hotel's wellness experience was to take shape.
Architectural volume under vaults — tubular pillars clad in celadon faience and white lounge chairs dialogue with the soft sheen of patinated vaults
The challenge — creating a wellness sanctuary under a layer of history
Designing a basement pool is never a trivial project. Doing so in a preserved heritage volume, under an existing slab and without altering the architectural identity, falls into another category of demanding requirements.
Three structural constraints
- Access — the tank modules had to be transported to the basement through existing access points, without modifying the structural work. Our design office had to dimension each element to fit through the existing doors and stairs.
- The humid environment — in the basement, without natural cross-ventilation, humidity control is crucial to preserve the surrounding heritage materials. 316L marine-grade stainless steel and controlled dehumidification were the only possible answers to this challenge.
- Visual coexistence — the pool was not to overpower or compete with the preserved vaults. It had to be an complementary architectural element, capable of capturing and reflecting the light from the illuminated alcoves.
A material that dialogues with the identity of the place
316L marine-grade stainless steel was not chosen solely for its corrosion resistance in a chlorinated environment — nor for its longevity of over forty years. It was chosen because, in this specific context, it was the right material response: a surface that captures reflections without reflecting them harshly, that dialogues with the brass patina without competing with it.
The Scotch-Brite finish we apply in our workshop softens the steel's shine and produces a subdued, almost warm reflection — in contrast to the cold mirror-like finish. This finish allows the material to blend seamlessly with the century-old brass of the vaults.
Custom design
No standard catalog could have met the requirements of this project. The pool was entirely custom-designed by our design office, based on surveys of the vault room and the structural constraints of the existing slab.
Geometry and Integration
The pool has an elongated rectangular shape that fits the rhythm of the alcoves. Its understated geometry amplifies the perspective between the lateral safes and creates a calming visual flow: the swimmer's eye, from the loungers, glides from the soft light of the safes towards the water mirror, then extends into the depth of the other side.
Hydraulics and Treatment
Given its use as a hotel and public facility, the hydraulic system was designed to ensure complete water renewal in less than 120 minutes, featuring:
- High-performance filtration (AFM glass, 10-15 micron fineness)
- Automatic pH + chlorine regulation with amperometric probes and a monitoring log compliant with ARS requirements
- A finishing UV treatment to limit chloramine formation and maintain respiratory comfort in the basement
Lighting
Four RGB LED projectors embedded in the tank allow for configurable lighting scenes according to the time of day. The characteristic perforated bottom of our stainless steel pools creates an underwater texture that reveals itself with varying light intensities, transforming the pool itself into an atmospheric element.
At night, the embedded RGB LED projectors sculpt the material and reveal the perforated texture of the stainless steel bottom.
Pre-fabrication in the Mérignac workshop
Like all our constructions, the Oceania Hotel Lille pool was entirely hand-fabricated in our Mérignac workshop, in the Bordeaux metropolitan area. Each element – wall panels, bottom, suction system – is cut and then formed by our team.
The pool was pre-assembled dry in the workshop to validate all dimensions and tolerances, then dismantled into transportable modules to allow it to be lowered into the basement in Lille.
Delivery and installation
The construction phase was one of the most delicate moments of the project. The transport of the modules between our Mérignac workshop and the Lille site was carried out by a company specialized in the transport of technical structures, with complete protection and custom palletization.
Access to the basement was made through existing circulation routes, without any intervention on the building's structural work. Each module was pre-dimensioned to the millimeter to pass through the doors, stairs, and narrow angles of the internal path. Once in place, the Steel and Style installation team welded the modules on site, connected the hydraulic and electrical networks to the dedicated technical room, and proceeded with filling and leak tests.
Our teams are perfectly accustomed to difficult access and on-site construction of stainless steel pools. They apply the same rigor as in the workshop.
The result — a dialogue between heritage and modernity
The final result is a space where two eras respond to each other without opposition. The patinated safes, illuminated by their original recessed lighting, frame a body of water whose cyan and turquoise nuances play with the amber light of the brass. The structural columns, clad in celadon faience, punctuate the space and guide the eye through the volume.
For hotel guests, the experience is unique: descending into the basement of a Lille building to discover an architectural pool in the former safe of a bank is as much an architectural curiosity as it is a moment of relaxation. This is precisely the kind of identity that premium hotel establishments are seeking today to differentiate themselves sustainably.
A redesigned guest experience
Beyond technical performance, this project illustrates a conviction: a high-end aquatic structure is not just equipment, it is a hospitality experience. Visitors entering this space are transported to another time – that of a century-old banking memory – and find a moment of contemporary suspension.
Stainless steel plays a subtle yet essential role here: it bridges the two eras, without rupture or excessive deference.
Recognized expertise in premium hospitality
The Oceania Hotel Lille joins a series of hotel projects that confirm our positioning with operators and investors in the sector. Our references include:
- Five Seas Hotel — Cannes: stainless steel infinity pool and TWO MIMO spa on the rooftop, with panoramic views of the Croisette
- Hotel & Spa Ribeauvillé — Alsace: indoor stainless steel pool with integrated jacuzzi, in the heart of the Alsace vineyard
Each project shares the same approach: an architectural interpretation of the context, custom manufacturing in an integrated workshop, and end-to-end support from preliminary design to water filling.
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Frequently Asked Questions — Stainless Steel Pools for Hotels and Heritage Sites
Can a stainless steel pool be installed in a heritage building or listed site?
Yes, this is even one of the use cases where 316L stainless steel excels. The pool is manufactured in the workshop, delivered in pre-cut modules to the dimensions of existing access points, then welded on site. No intervention on the heritage structural work is necessary, unlike traditional concrete pools which require in-situ formwork and significant excavation.
How long does it take to build a stainless steel hotel pool?
The typical timeline spans 4 to 7 months from quote signature to water filling: 4 to 6 weeks for technical studies and execution plans, 8 to 14 weeks for workshop fabrication depending on complexity, 1 to 2 weeks for on-site installation and water filling. The exact timeline depends on the workshop's schedule at the time of order and site constraints.
Why choose 316L stainless steel for a hotel project?
Marine grade 316L stainless steel offers a lifespan of over 40 years with minimal maintenance, total compatibility with the ARS treatments required for public establishments, a non-porous surface that prevents bacterial proliferation, and a contemporary and durable aesthetic. From an economic perspective, the TCO over 30 years is lower than that of a traditional tiled pool.
How is a stainless steel pool installed in a basement?
The pool is cut into pre-assembled modules in the workshop, sized to fit existing access points (doors, stairs, service lifts). Once in place, our team welds the modules on site with leak control, connects the networks to the dedicated technical room, and proceeds with filling. No structural work intervention is required.
What is the budget for a high-end stainless steel hotel pool?
The budget for a custom stainless steel hotel pool varies according to dimensions, project complexity, and equipment (water treatment, heating, dehumidification, lighting). As an indication, a complete hotel project (tank + networks + treatment + installation) generally ranges from €200,000 to €500,000 (excl. VAT) for a typical 8×5 m to 12×5 m pool. We provide a precise budgetary estimate within 5 working days of receiving the file.
Does Steel and Style work on heritage rehabilitation projects?
Regularly. Several of our projects are set in heritage contexts: Hôtel Oceania Lille (former bank vault), Hôtel & Spa Ribeauvillé (Alsatian vineyard), Le Diana Cannes (renovation of an iconic establishment). Our modular approach and workshop manufacturing allow us to operate in constrained environments without impacting existing buildings.
What maintenance is required for a 316L stainless steel hotel pool?
316L marine grade stainless steel requires virtually no surface maintenance (no joints, no tiles to repair). The only recurring maintenance items are those for treatment equipment: probe calibration, UV lamp replacement (8000 hours), filter cleaning and backwashing. Steel and Style offers an annual maintenance contract for ERP establishments.
Do you have a hotel or heritage project in mind?
Whether you are a hotel operator, investor, architect, or project manager, our design office supports you from the initial sketches to validate technical feasibility, size the structures, and integrate the pool or spas into the overall architectural coherence of your project.
Our hotel references extend across France, Monaco, Switzerland, the United Kingdom, and the Caribbean — all conceived as unique architectural pieces serving the identity of the establishment.
Romain Wanecque
Romain WANECQUE is the founder of STEEL AND STYLE. A graduate with a master's degree from the Polytechnique engineering school in Montpellier, he also holds an IWT (International Welding Technologist) and an IWE (International Welding Engineer).
Steel and Style project — Oceania Hotel Lille. Integrated workshop in Mérignac, Bordeaux metropolitan area. 200+ projects completed in France, Monaco, Switzerland, the United Kingdom, and the Caribbean for premium hotel and residential clients.
