MVRDV and Zecc Architecten have won the competition to transform the St. Francis of Assisi Church in Heerlen into a public swimming pool. Originally built over 100 years ago, the church stopped hosting services in 2023, presenting the municipality with the opportunity to repurpose the building for community use. Nicknamed Holy Water, the adaptive reuse project is meant to give this listed national monument, with its recognizable silhouette, a new social function while preserving its historic elements. The design was created through a collaboration between MVRDV, Zecc Architecten, IMd Raadgevende Ingenieurs, Nelissen Ingenieursbureau, and construction economics consultancy SkaaL, and is expected to be completed at the end of 2027.
The design features an illuminated circular canopy at the main entrance, referencing the church's heritage while introducing a contemporary element that bridges past and present. Once inside, visitors will proceed through the church's aisles to reach the changing rooms or a catering area, both located at the rear of the building. Glass walls separate these passages from the climate-controlled central pool space. The projected lighting above the pool was inspired by the original church lamps seen in historic photographs, with four rows of fixtures also serving as lane markers for swimmers.
To accommodate the swimming pool, the existing floor will be removed and replaced with a new mosaic surface surrounding the pool and covering the pool floor. The mosaic is planned to reference the church's original colors, materials, and stained-glass windows, with a design made in collaboration with local artists to echo the existing murals in Heerlen. The church's pews will be repurposed into seating integrated within the glass walls, serving as benches for swimmers on one side and bar-height tables for spectators on the other. The original pulpit will be adapted to serve as the lifeguard's station.
A key feature of the project is a new adjustable pool floor, designed to introduce flexibility to the former nave. The movable floor can be raised or lowered to support various activities and accommodate swimmers of different ages and abilities. When fully raised, the pool floor conceals the water entirely, creating a flat surface that allows the space to host cultural or social events. It can also be set to hold a shallow layer of water across the floor, forming a reflective surface that creates the illusion of a "mirror church," giving visitors the sense of walking on water.
To protect the church's historic materials and artworks from humidity while heating the pool area, the design incorporates compartmentalized glass walls that preserve the surrounding stained glass and interior finishes. The roof will be insulated from the outside to prevent excessive heat loss while maintaining the view of the original brickwork from the inside. After insulation, the existing roof covering is planned to be reinstated. The wooden ceiling structure will be retained and enhanced with sound-absorbing panels to improve acoustics. Technical systems, including air handling units, will be discreetly integrated into the basement.
This transformation is part of a broader revitalization of Heerlen's city center, which also includes the arrival of a Roman museum and the renovation of the Royal-Rivoli cinema. Other recent news on adaptive reuse projects worldwide includes Garcés de Seta Bonet and Marvel Architects' winning proposals to convert a former power plant into Catalunya Media City, and Renzo Piano's 35,000 m² redevelopment of a department store on the Zeil in Frankfurt's city center. More broadly, Los Angeles is set to implement its Citywide Adaptive Reuse Ordinance (Citywide ARO) in 2025, recently approved to help address the housing shortage. Additionally, the 2025 Obel Award has launched its Ready-Made theme, recognizing projects worldwide that prioritize reuse and repurposing in architecture for the common good.
