The UK Green Roof Organisation GRO has published its long-awaited best practice guidelines for biosolar roofs – roofs that integrate solar / photovoltaic (PV) panels over a green roof. This clarifies details on roof design, wind uplift calculations, minimum height of panels; construction of the solar base; distance between the roof edge and the panels; firebreaks and necessity of maintenance visit every six months.
The GRO Biosolar Best Practice Guidelines not only brings clarity for manufacturers, installers, maintainers of biosolar roofs, but also for the developers and architects that commission them, and the owners / managers of the buildings that feature biosolar roofs.
We outline the key takeaways of the guidelines. Download your copy of the guidelines here.
“As one of the UK’s leading installers and maintainers of biosolar roofs, Pritchard & Pritchard welcomes the GRO Best Practice Design Guidance. As a company we have always followed the German FLL guidelines, EU Eurocodes, UK BSI and BRE guidelines upon which the new GRO guidelines are based, but we appreciate the clarity that these excellent guidelines bring for our industry and particularly for the developers and architects who are increasingly interested in biosolar roofs,” said James Beattie, Director of Operations. Pritchard & Pritchard and a member of the GRO board.
- For a more in-depth look at the GRO Best Practice Guidelines, see this article on Biosolar-roofs.com.
The top 10 takeaways from the GRO biosolar guidelines
1. Biosolar systems can only be installed on a flat roof or an angled roof of up to 5 degrees.
2. There must be a design plan showing positioning of the solar panels.
3. There must be a wind loading report (also called a wind uplift calculation) that determines the necessary ballast to secure the solar bases. This must be in accordance with BS EN 1991-1-4 “Actions on Structures” and BRE Digest 489.
4. Solar bases (that holds the panels) are designed to be integrated into a green roof system and are compliant with BS EN 1991 1-4:2005 and BS EN 1999 1-1:2007 Eurocode 9 “Design of Aluminium Structures” and BS EN 1993 Eurocode 3 “Design of Steel Structures”.
5. Spacing between the PV panels should be sufficient to allow maintenance and safety, and in accordance with manufacturer guidance.
6. The height of the panel at its lowest point should be 200mm above the substrate.
7. PV Panels should be at least 1.5m from the edge of the roof and 750mm from the edge of rooflights or atrium features.
8. There must be a firebreak of 1m width every 40m. PV Panels should not encroach on the firebreak.
9. The installation of the panels and electrical cabling should be installed in accordance with MCS guidelines.
10. Biosolar roofs (green-roof portion) should be maintained twice a year to ensure:
- Build-up of organic matter does not become a fire risk.
- Vegetation is not in danger of shading the PV panels.
- Check that there is a minimum gap of 200mm between lower edge of PV panel and substrate.
- Old biomass is removed each autumn.
- Firebreaks are kept clear.
Introducing: Biosolar-roofs.com
Biosolar-roofs is the world’s first website dedicated to roofs that combine living roofs and solar power. This is the go-to resource for knowledge sharing, best practice, guidance, research, news and insights into biosolar roofing. Highlights of Biosolar-roofs include:
- Repository of biosolar research – round up of all current research.
- The ultimate guide to plants for biosolar roofs – recommended by industry experts.
- The key guidelines and regulations impacting biosolar roofs – best practice, BNG, SuDS etc.
- Biosolar FAQ / explainer – all your questions answered by the experts.
- Benefits of biosolar roofs: facts, stats and evidence – environmental, economic and regulatory benefits.
- Types of biosolar roof – wildflower, sedum, blue, biodiverse etc. – wildflower, sedum, blue, biodiverse etc.
- How biosolar roofs work and make solar panels more efficient – technology before hype.
- Biosolar systems – biosolar systems / formations explained and assessed. – biosolar systems / formations explained and assessed.