Vegetated roofs can significantly reduce surface temperatures, with intensive green roofs up to 33.3 °F cooler than non-vegetated surfaces. Green roofs also support urban biodiversity and act as stepping-stone biotopes for insects, birds and other plants.

Credits: envato elements;

A green-roof mandate dating back to 1991 requires vegetation on all new or renovated flat roofs unless they’re terraces, and roughly 40 percent of flat roofs now support plants. Green roofs improve insulation, lowering energy demand for cooling in summer and heating in winter, and extend roof lifespan by protecting waterproofing layers. Some roofs, like a century-old site near Zürich, have become orchid-rich meadows with more than 175 plant species, illustrating their ecological potential.