Sponge city

Climate resilience is central to urban developments. Faced with the emergence of new environmental and societal challenges, more and more Sponge Cities are flourishing around the world. In Switzerland, Fribourg is a pioneer city and canton, applying this urban planning model on the bluefactory site.

Looking resolutely to the future, BFF SA is committed to setting an example in the management of its site’s hydraulic balance. In collaboration with SINEF, the company is setting up an ambitious project that takes a systemic approach to capitalise on multiple sources of water and energy, pooling needs and centralising production. This water management concept will be phased in, using local resources to adapt as site development progresses.

The concept developed by SINEF focuses on various hybrid water management solutions that will make it possible to reintroduce a more natural water cycle into the heart of a city where the cycle is disrupted by impermeable surfaces. The bluefactory site’s DNA makes it the ideal place to implement these new approaches, which consist of optimally managing stormwater and purifying wastewater locally. Existing building stock will be upgraded and adapted, both above and below ground, to make the most of on-site water. New developments will be designed to promote a significant development of biodiversity. An urban pond, permeable green spaces and green roofs will help fight against heat islands and create a congenial living environment, in keeping with the innovation district’s evolution. The existing reservoir is to collect and store not only excess rainwater and water from the Les Pilettes spring – once operated by the Cardinal brewery – but also wastewater, which will be purified and treated on site using innovative biological processes. Urine-based fertilizer will be produced on site. The thermal potential of collected water will be exploited and used to supply toilet tanks and for watering and cleaning the site’s public spaces.