A green roof with meandering pathways disguises this weathering steel water treatment facility, which Henning Larsen has completed on the island of Zealand, Denmark.
Named the Solrødgård Water Treatment Plant, the building contains a recycling centre and wastewater treatment plant for the city of Hillerød, and is topped by a public urban park.

Henning Larsen designed the rooftop park to reduce the facility's visual impact and invite the community to visit. The studio hopes this will put them "face to face with their use of resources", sparking conversation about water scarcity and climate change.
"Nearly two-thirds of the world's population experiences severe water scarcity during at least one month of the year," said the studio. "As climate change and global crowding intensify, this figure will only become more severe. The park aims to open a community dialogue on resource use and climate awareness by creating public appeal within municipal infrastructure."

Beneath the green roof, Solrødgård Water Treatment Plant is a single-storey building that is designed to be easily expanded in the future.
The water treatment works is divided in two by an outdoor corridor that runs the length of the building. Above it, a bridge connects either side of the park.

Henning Larsen has lined this corridor with weathering steel and floor-to-ceiling glass to invite visitors to look inside the building.

Teamed with a series of angular skylights that ...