In June 2015 I attended the BioSolar Green Roof Pilot Course run by the Scandinavian Green Roof Institute. To be one of 12 'Green Roof professionals' accepted from around the world, I was both privelleged and excited to have such an opportunity to further my green roof knowledge.
Held at the Augustenborg Botanical Roof Garden in Malmö, Sweden, the course was an information packed 5 days of valuable green roof material. A combination of theoretical, and practical learning provided the perfect opportunity to take what we learnt in the class room onto the roof above.
This year the course was supported by the BioSolar program. A program which aims to teach the required skills to design, construct, install and maintain BIODIVERSE green roofs when combined with solar. Numerous studies worldwide continue to prove that solar is more efficient when installed on a green roof, in comparison to solar on a conventional roof. Simply due to the fact that the surface temperature on a green roof is lower . What has become apparent in recent times across the UK and Europe is that there is a significant lack of workforce skills when it comes to combining solar and green roof technology. The course taught simple ways to harmonize and optimize these 2 sustainable building elements.
Firstly in the design of a biodiverse green roof the solar panels need to be considered; not only placement for maximum energy efficiency but also for the physical impact the panels have on the roof. It must be considered that the panels create different conditions (shade, wind shelter, rain shelter) so drainage, substrate depth and planting must be adjusted accordingly. This is often thought of as a negative, but in regard to creating a more biodiverse green roof it can actually be a big positive.
To acheive an optimal Biosolar green roof it is critical in the construction and maintenance phases that both the solar and biodiverse aspects are respected by all contractors. The course taught installation, maintenance and management techniques for acheiving the best possible results. From ideal substrate depths and plant selection surrounding the solar panels, to simple maintenance practises for maximum solar energy production.
The course went into further detail for creating biodiverse extensive green roofs. Topics covered included;
- site considerations
- safety at heights
- waterproofing, protection and drainage layers
- drainage requirements
- ideal substrate make-up and desired substrate water holding capacity
- different substrate depths
- plant establishment
- plant identification
- additional methods of supporting invertabrates and pollinators
Essentially a well designed, constructed and maintained Biosolar Green Roof should provide a biodiverse environment which supports invertebrates and pollinators while efficiently producing solar energy.
The course provided the opportunity to take part in 2 green roof installations on the Augustenborg Botanical Roof Garden. It was then that we really got our hands dirty. Firstly hand mixing the substrate. Then laying out the protection and drainage layers. Once the substrate was craned onto the roof, emptied, shoveled, and raked into position it was time for planting. Special guest Peter Korn (Swedish gardening guru with a passion for growing plants in harsh environments) joined us on the final day to help with the planting process. Peters knowledge of plant establishment in harsh environments was very relevant to planting an extensive green roof. His book, Peter Korns Garden is well worth reading for anyone wanting to establish plants in what are generally thought of as difficult growing conditions.
A highlight of the 5 day course was the Green Roof Tour. In one afternoon we visited 2 recently constructed green roofs in Malmö, 1 in Copenhagen, as well as a supplier of sedum matting. Jonatan Malmberg from the Scandinavian Green Roof Institute gave great pratical advice on each roof from a biodiversity point of view. He pointed out elements of the green roofs which worked well, and then suggested ways in which the roofs may have been modified to better support invertabrates and pollintators.
The course concluded with us designing our own 'BioSolar' green roof. Having learnt so much and feeding off the 'Green Roof Passion' of the Scandinavian Green Roof Institute we all put pen to paper and then presented our ideas to the class. The 12 'Green Roof professionals', who gathered for the 'BioSolar' Green Roof Pilot Course explained their way of combining solar on a green roof and creating a biodiverse environment.
A short course that will have a long lasting influence on me- The importance of creating 'BioSolar' Green Roofs. With an ever increasing population leading to continuing loss of green space in our cities, as well as the need to become less dependent on fossil fuels - 'BioSolar' Green Roofs are the answer.