France passes a law requiring new
rooftops to be covered with plants or solar
panels
March 30, 2015
BY: TYLER FYFE
Earlier this month France passed legislation in response to pressure from environmental activists
that all buildings constructed in commercial zones must have sections roofed with solar panels or
green spaces.
According to smog readings by air pollution watchdog Plume Labs, the air pollution in Paris
briefly became the highest in the world prompting the city to respond by making all public transit
and bike-sharing programs free.
In densely populated cities, green roofs can significantly improve air quality by absorbing
pollutants while producing oxygen. A 2014 study by The Gulf Organisation for Research and
Development found that plant-covered roofs act as a drain for nitrogen, zinc and lead—runoff of
zinc and copper being 90 per cent in dissolved form. The roofs reduce the damaging effects of
acid rain by raiding the PH value of rain and runoff water.
This is the design for a sustainable high school planned to
be built in Revin, France.
Toronto was the first city in North America to pass a bylaw that maintained that green roofs must
be included in the design of all new buildings. Although tree-covered roofs date back to ancient
civilizations like Babylon, recently they have been embraced as a way of making cities more
liveable by saving energy through a method that’s also quite fashionable.
While these roofs were initially sought by cities as a way to reduce the costs of acquiring land in
metropolitan areas for public parks, they have a significant affect on moderating temperature by
acting as a passive-cooling system. Plants provide direct shading while reflecting incoming solar
radiation and help cool buildings through the transpiration of water to reduce thermal loading.
Green roofs also help to promote wildlife activity by providing temporary habitats for migrating
birds, while also stimulating biodiversity by increasing decomposing organic material allowing
organisms to thrive.
Currently, Germany is the leader of green roof research with more than 10 per cent of houses
having plant-covered roofs and that number increasing by 10-15 per cent each year.
The Environmental Protection Agency estimates the upfront investment for green roofs to be $10
per square foot for modest roofs and $25 per square foot for more intense designs. However,
these initial costs are offset by the benefits of decreased energy expenditure and the lengthened
lifespan of green roofs.
France is making significant effort to address the concern of growing rates of pollution having
adverse affects on the health of citizens. Last year, the World Health Organization stated in
apress release that outdoor air pollution has been classified as an environmental cause of cancer
deaths.
The country joins the ranks of forward-thinking cities that have enshrined a green mandate into
law such as Toronto, Basel and Tokyo, who passed the Green Tokyo Plan in 2001.