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Green roofing services for renewability
Published on 12 February 2021
Spain
Comunitat Valenciana
This is the good practice's implementation level. It can be national, regional or local.
About this good practice
The main problem addressed relates to energy savings in exposed buildings to the Mediterranean climate. Roofs in buildings must be shielded from solar radiation for avoiding overheating (or saving energy on climate control).
Additionally, in urban areas roofs provide runoff and stormwater management with relevant environmental benefits: building insulation; energy saving for climate control; drainage Urban Sustainable Systems (SUDS) capable of retaining water into the substrate; reduce the runoff peak and volume; Green roofs help in decarbonizing housing stock, and lower costs for roof waterproof maintenance.
Part of the roof of the Social Center located in Benaguasil was renovated in 2014. One year before the renovation, the monitoring process had started controlling the thermal confront and the energy consumption of the air conditioning system. To ensure the conditions were the same, the monitored area was not used during those years.
The change on the roof was mainly on the top layers, changing the gravel layer to a green roof with a water storage layer. As expected, the maximum temperature has been reduced considerably on the top layer. The same happened with the energy consumption and with the runoff water.
Additionally, in urban areas roofs provide runoff and stormwater management with relevant environmental benefits: building insulation; energy saving for climate control; drainage Urban Sustainable Systems (SUDS) capable of retaining water into the substrate; reduce the runoff peak and volume; Green roofs help in decarbonizing housing stock, and lower costs for roof waterproof maintenance.
Part of the roof of the Social Center located in Benaguasil was renovated in 2014. One year before the renovation, the monitoring process had started controlling the thermal confront and the energy consumption of the air conditioning system. To ensure the conditions were the same, the monitored area was not used during those years.
The change on the roof was mainly on the top layers, changing the gravel layer to a green roof with a water storage layer. As expected, the maximum temperature has been reduced considerably on the top layer. The same happened with the energy consumption and with the runoff water.
Resources needed
For implementing the proposed good practice requirements are empty flat roof; a waterproofing membrane to be covered by an adequate substrate over a drainage layer. Further to that, an irrigation system, fall arrest bars and auxiliary tools, together with engineering labour and installation.
Evidence of success
Successful thermal inertia balance for the building: 15-20ºC peak temperature reduction, softened storage effect and delayed peaks to the afternoon.
Energy savings in air conditioning from 20 to 25%, runoff water reduction in volume and peaks up to 63%, eliminating it on small intensity events.
Last but not least, drainage water quality thanks to substrate filtering allowed rainwater reuse for irrigation with minimal freshwater intakes.
Energy savings in air conditioning from 20 to 25%, runoff water reduction in volume and peaks up to 63%, eliminating it on small intensity events.
Last but not least, drainage water quality thanks to substrate filtering allowed rainwater reuse for irrigation with minimal freshwater intakes.
Potential for learning or transfer
Experience on waterproofing membrane leak tests, slope roof requirements and load bearing capacity. Substrate selection for green roofs including suitable drainage and construction layers with a gravel perimeter. Safety measures around the whole roof including fall arrest system design.
Further information
Website
Good practice owner
Organisation
Regional Government of Valencia
Spain
Comunitat Valenciana
Contact
Professor