The PSES Building has a green roof: fifty percent of the surface is covered by vegetation, providing efficient thermal isolation throughout the year – it prevents cooling in wintertime and heating during summer, helping to maintain a comfortable temperature within the building at all times, independent of the use of the air conditioning system, thus minimizing the need for electricity. Additionally, the green roof serves as a research laboratory and an open classroom for students and the public.
The green roof garden comprises indigenous water-efficient plants, primarily succulents and cacti. These grow on a special (non-soil) bedding, composed of tuff (or tufa) – a volcanic rock; a water drainage layer; and durable sealing sheets, which prevent leaks as plant roots cannot penetrate them. The plants are irrigated using purified water from the PSES Building's green basin.
The green roof requires almost no maintenance. The small plants don't need pruning, they are watered by drip irrigation, and the roof does not need to be tarred and whitewashed. Additionally, the green roof absorbs rain water, even in a blizzard, avoiding gutter overflows or flooding of sewage. Any excess water is drained in a controlled manner into the municipal sewerage system.
Alongside the garden, a small energy producing wind turbine is installed on the roof, to be used primarily for technology demonstration and for teaching and research purposes. This exceptional system requires constant maintenance, providing additional experience for learning and research.