Village lighting Ardez, Plan Lumière Scuol (CHE)

The Lower Engadine is one of the darkest regions in Central Europe. For the municipality of Scuol, which covers 438 square kilometres and borders the Swiss National Park, this darkness is a quality worth protecting. The lighting design practice nachtaktiv GmbH developed a Plan Lumière that improves orientation for pedestrians while safeguarding the night sky. The historic village of Ardez served as a pilot project. The custom luminaire CLER was developed by ewo within the ewoIndividual programme, according to the specifications of lighting designer Reto Marty. In 2025, the Swiss Lighting Society SLG recognised the project with a commendation at the Prix Lumière, Switzerland’s most prestigious lighting award.

The municipality of Scuol comprises six villages: Ardez, Ftan, Guarda, Scuol, Sent and Tarasp, which merged in 2015 to form what is now the largest municipality in Switzerland by area. Less than one percent of the municipal area is developed land. The remainder is mountain landscape, pastureland, and large sections of the Swiss National Park, the oldest national park in the Alps. The night sky above the Lower Engadine reaches brightness levels that astronomers classify as near-natural darkness. The Milky Way is visible there with the naked eye, which has become rare in Central Europe.

The Plan Lumière that Reto Marty developed for Scuol follows a consistent philosophy: light only where it is needed. Dynamic control across the night hours. Minimal intensity. Precise direction of light onto paths and roads intended for people. This approach aligns closely with ewo’s guiding principle "empowering wellbeing outdoors".

Ardez as a pilot project: new light in a historic setting

The village of Ardez was selected as the pilot project. Its building fabric, with narrow, winding lanes and Engadine houses built from rubble masonry with sgraffito facades, dates from the 17th century and is listed as a heritage site. The historic fabric of the village brings a range of specific challenges. There is no dedicated grid infrastructure for public lighting. All luminaire mounting points are on private buildings, whose owners must approve any changes. Mounting heights vary between three and ten metres. Installing new fixing points into centuries-old masonry is ruled out. Reto Marty and ewo developed a luminaire concept that meets these exceptional conditions.

The CLER is a project-specific luminaire, developed within the ewoIndividual programme. Its silhouette is timeless and integrates naturally into the listed character of the village. The conical form of the luminaire is functionally driven. It keeps snow loads low, an important criterion for a location at over 1,200 metres above sea level.

Three mounting variants cover all structural situations in Ardez: catenary suspension for the lanes, wall brackets on building facades, and post-top mounts for freestanding locations. All variants share the same luminaire form. The visual appearance of the village remains consistent.

The photometric differentiation lies within. ewo equipped the CLER with a broad range of lenses, selected according to each situation: there are optimally matched light distributions for pedestrian and cycle paths, for roads, for squares and large open areas, and for the catenary luminaires above the lanes. Many of these lenses are fitted with a Rear Backlight Shield (RBS). This shielding element, invisible to the observer, is mounted directly onto the lenses and prevents light from being emitted backwards onto facades and into windows. In a region that treats light emissions as an ecological concern, this is a central criterion.

The catenary luminaires use ewoLightTile technology, a patented area optic that produces homogeneous, low-glare illumination and makes individual LED points visually disappear. These luminaires are also equipped with Tunable White. Via DALI control, the colour temperature can be set between 2200 and 6500 Kelvin. In the village centre, the installation operates at 2700 Kelvin; at the village periphery at 2200 Kelvin.

Alongside the precision optics, a lighting control system is central to the design, reducing energy consumption and unwanted light emissions. All luminaires are equipped with a Zhaga Book 18 interface and DALI interface. Motion sensors regulate light levels based on presence detection. From 10 pm, a first nighttime dimming step takes effect; from midnight, a further reduction follows. Outside the village centre, lighting activates only when movement is detected. The result is an energy saving of at least 75 percent compared with the previous sodium vapour installation. The municipality saves approximately CHF 6,800 per year in electricity costs and a further CHF 3,800 in maintenance costs.

What the new lighting achieves

Aerial photographs from 2025 showing the new state and from 2023 showing the old state clearly illustrate the difference. The spill light from the old sodium vapour lamps, the effect of which had uniformly brightened the streets, squares, building facades and the surrounding area has been significantly reduced. Lanes and paths are more evenly and normatively lit. The light reaches only the surfaces it is intended for.

The new lighting atmosphere was perceived by residents as a significant change and required explanation. The absence of spill light was subjectively experienced as darkness, even though the footpaths are more brightly lit than before. Reto Marty accompanied this process throughout. With his office and home in Scuol, he knows the municipality and its residents. In his assessment, direct dialogue on site, explaining the concept in conversation with residents, was of equal importance to the technical planning.

Recognition and continuation

The Swiss Lighting Society SLG recognised the project in 2025 with the commendation prize at the Prix Lumière, confirming the quality of the planning and the distinctive attitude of the project towards night and nature. The positive experience from the pilot project in Ardez is now leading the remaining village districts to be re-lit one by one according to the same concept.