Green roofs contribute to passive cooling by adding a vegetated layer that reduces heat transfer into the building. This works through two key mechanisms:
shading of the roof surface and evaporative cooling, where plants evaporate water into the air, thereby absorbing heat in the process.

In hot climates green roofs can significantly lower indoor temperatures by preventing direct solar radiation from heating the roof structure. The growing
substrate also acts as insulation, reducing heat flow into the building during the day and heat loss at night.

Additionally, the evaporative cooling effect of plant transpiration helps cool the surrounding air, improving the microclimate above and around the building.
By minimizing surface temperatures and mitigating heat accumulation, green roofs can decrease energy demand for cooling while enhancing urban
biodiversity and managing stormwater retention.