Green roofs

The University of Bologna is experimenting with green roofs

The project

The initiative involves installing green roofs and hanging micro-gardens on the horizontal roofing surfaces of university buildings.


The goals

  • thermal insulation - vegetative roof coverings contribute to reducing heat loss from inside to outside, with a consequent reduction in energy consumption
  • soundproofing - due to the mass of the component layers and vegetation
  • bioclimatic improvement - by replenishing biomass lost due to the effect of cementing, green roofs enable carbon dioxide to be converted into oxygen through photosynthesis. Furthermore, by reducing emissions caused by the use of air conditioning systems, they contribute to improving environmental liveability
  • high water retention - the elements that make up the covering and substrates return up to 80% of rainwater to the environment through evapotranspiration, thereby reducing stormwater runoff to the drainage system
  • decrease of the heat island effect - roof vegetation absorbs dust

State of progress

Currently there is a total of over 1000 square metres of green roofing installed on a number of university buildings.

After an initial experience at Ingegneria - Lazzaretto (where 2 extensive green roofs were installed, consisting of a flat green roof, a meteorological station and water runoff sensors, for a total of 120 square metres of roofing), the pilot project was carried out at the School of Agriculture and Veterinary Medicine - CAAB, where 5 extensive green roofs were installed, covering a total area of 932 square metres.

Part of the roofs at the CAAB were made available for research both for the study of alternative plant species to traditional roofs and for the analysis of drainage water.

An extensive green roof was then installed on the flat roof of the "Ex Croce Rossa" building in Via San Petronio Vecchio. The choice of crassulaceae is aimed at minimising both irrigation and maintenance as they are plants with reduced water requirements and this allows better thermal and acoustic insulation. 

Green roofs at CAAB

Tetti verdi al CAAB
Tetti verdi al CAAB
Tetti verdi al CAAB
Tetti verdi al CAAB