Sainte-Luce 9

Located on Avenue Sainte-Luce in the heart of Lausanne, in a dense and rich historical district, the building occupies the former site of the First Church of Christ's place of worship, Scientiste, designed by architect Jean-Pierre Cahen and inaugurated in 1952, which, due to its size, no longer met the needs of the members. In 2011, the site was sold by the Church on the condition that a building would be constructed with two distinct programmes: rental flats on the upper floors and a new place of worship on the ground floor.
The new building adopts a minimalist and sophisticated architectural vocabulary designed to respect the memory of the former church building and the historic identity of the neighbourhood. A major challenge of the project is to create attractive, high-quality living spaces in this new flat block, which is set in a very dense urban context, with limited views of the lake and low light levels. In developing the project, the proximity of the buildings opposite led us to exploit the great potential of the north facade, which opens onto a large, light-filled inner courtyard of a historic building, bordered by old chestnut trees.
The building houses 40 flats ranging from 2.5 to 4.5 rooms. The flats are arranged around a north-south axis, with living rooms and bedrooms alternating regularly in orientation. In cross-section, to achieve a more luminous and noble effect in the living rooms, the project plays with an alternating rhythm of heights on each floor. The interweaving of the different floors gives a ceiling height of 2.70 m in the living rooms, while the bedrooms have a standard height of 2.40 m.
Loggias enhance the distribution of the flats. They communicate with the living room and offer a diagonal view, reducing the effect of overlooking neighbouring buildings. These loggias also provide year-round comfort - accordion-style glazing allows them to be fully opened up to the outdoors in summer, and used as winter gardens in cooler seasons. The façade, combining precast concrete fascias and mineral render, blends harmoniously into its surroundings. It invites an extended reading of the ‘interlocking’ section - as a common thread, the size of the windows and the horizontal shelf linking the living room to its loggia - which, for its part, is located on each floor on the vertical axis of the stairwell.
The penthouse flats are south-facing, with magnificent lake views. The building has a vegetated roof to retain rainwater and improve the thermal comfort of the top-floor flats. An installation of photovoltaic panels on the roof supplies the heating system via air-water heat pumps. The flats are air-ventilated using a highly efficient low-tech concept with low electricity consumption, i.e. single-flow ventilation.
The choice of materials is based on a palette of light, warm colours, both indoors and on the façade and in the church interiors. This palette varies subtly between the exterior and interior. The colours and materials of the façade ‘carry over’ to the interior of the stairwells and loggias; those of the flats have their own identity.
In the living areas, terrazzo flooring blends with oak parquet and light grey lacquered woodwork. Particular attention has been paid to the finish of the built-in furniture and bathroom fittings. Sand-blasted earthenware tiles cover the entrances to the building and the walls of the loggias, reflecting the light from outside into the living room and at the same time enlivening the façades.
The residential units are accessed from the north side, creating a separate entrance to the church from the street on the south side. The stairwells, with their refined, high-quality finishes - terrazzo floors, light-coloured prefabricated concrete staircases and oak doors - benefit from natural light reflected through a bay window in the loggia.
Besides access to the car park, the ground floor houses the church premises. The large worship room, lit by a skylight on the north facade, allows the space to be adapted to the needs of the churchgoers thanks to sliding oak panels. The atmosphere of the room can be adapted using backlit walls, plus a skylight that diffuses natural light onto a plant altar. A bright reading room and a nursery area with large bay windows complete the ensemble. The overall effect is one of alternating natural and artificial light, enhanced by warm, timeless oak finishes.