Spatially, the roof is organised through a modular grid of quadrangular forms that combine vegetation, circulation, and areas designed for temporary or permanent use. This structure supports adaptability across different routines, from school visits and educational programmes to cultural events and informal leisure. The concrete grid rests on pilotis, allowing the intervention to minimise impact on the existing construction and reduce disturbance to the valley’s topography.

This new public surface is conceived as part of a wider territorial system. Pedestrian routes and viewpoints are extended across the site, strengthening its relationship with the surrounding landscape and with Bragança Castle. A continuous walkway along the Fervença River connects the plant to the watercourse, reinforcing the link between natural systems and the infrastructure responsible for water treatment. Existing accesses are preserved and enhanced so the intervention can integrate into the city’s broader network of public space.

Visual connections between the public roof and the interior operations of the treatment plant are calibrated through controlled moments of transparency. These openings introduce an educational dimension to the experience of the site, allowing visitors to relate the visible processes of treatment to the landscape condition above.