London accounts for over 40% of the total UK green roof market and ranks eighth in the global league table of green roofs by density. That is according a report published in April by the European Federation of Green Roof and Green Wall Associations and Livingroofs.org on behalf of the Greater London Council.
Living Roofs and Walls – from policy to practice charts the progress of green roofs and wall development in London over the past 10 years, and as the title suggests it places public policy at the heart of the success:
"Green roofs... and green walls... have, over the last decade, become the most obvious manifestation of urban greening in London. This has been driven by the ambitious and pioneering Living Roofs and Walls Policy which was first introduced into the London Plan in 2008".
The London Plan, first published in 2004, is the spatial development strategy for the Greater London to create an economically rich, diverse and safe city that can meet the challenges associated with population growth and climate change. On this latter point, the London Plan has set in place a number of policies in order to reduce carbon emissions by 60% against 1990 levels by 2025.
Under Policy 5.11, the presumption is that all major development proposals should be designed to include green roofs and walls, not only to mitigate and against adapt to rising temperatures, but to improve biodiversity and act as sustainable urban drainage.
As a result, green roof and wall uptake in both large and small developments has increased annually across London ever since. Although the main focus of activity has been in the inner London boroughs, activity has been a few of the outer London boroughs where there is major regeneration.
In the inner London boroughs - the Central Activity Zone (CAZ) - green roofs covered 290,000m2, which equates to 1.26m2 of green roof per inhabitant (2017 figures).
The total area of green roofs in the Greater London Area was 1.5 million m2, which equates to 0.17 m2 of green roof per inhabitant (2017 figures).
The CAZ figure is higher than many other cities in the world which are famed for their green roofs. The table below ranks cities in terms of square metres of green roof per inhabitant which is in line with the World Health Organisation’s urban health indicator of green space per urban inhabitant. The figures reveal that while certain cities have an impressive total green roof area, the density is actually relatively low, compared to London’s CAZ.
Under the ‘Combined Authorities (Spatial Development Strategy) Regulations 2018’, Greater Manchester, Liverpool City Region and the West of England (Bristol, Bath and Weston-Super-Mare) devolved authorities have the power to plan and implement their own equivalents to the London Plan. All three authorities have already published their green infrastructure strategies, which includes green roofs). The adoption their own London Plans with a presumption that future developments should include green roofs, may help these regions catch up with the capital and push the UK further at the forefront of green roof adoption.