The law approved by the Socialist government was a scaled-back version of a law proposed by environmental groups asking for green roofs to cover the entire rooftop surfaces on all new buildings constructed in France. The compromise law gives businesses the option of installing solar panels instead or partially cover the rooftops with living foliage.
There are many advantages to having grasses, shrubs and flowers, or other flora covering a structure’s rooftop. The most obvious is the insulating effect, reducing the need to heat or cool the building, depending on the season, Green roofs also help to retain water, reducing runoff and other drainage issues.
Green rooftops help in favoring biodiversity, giving birds, bees and other urban wildlife access to an environment that is sometimes missing in the urban jungle today. And green rooftops will aid in reducing pollution, reducing greenhouse gas emissions and improving air quality.
Green rooftops can reduce the urban heat island effect
We all know how hot a city can be in the summer. This is called the urban “heat island” effect. This effect comes about when buildings, roads, and other developments replace open land and vegetation, causing surfaces to become moist and impermeable. This in turn, causes the surfaces to heat up higher than the surrounding atmosphere. According to the EPA, the heat island effect can cause temperatures to become 1.8°F to 5.4°F warmer than surrounding areas in the day, and 22°F warmer at night,
France feels their green roof law is trailblazing and will change the urban landscape in cities all across the country, inspiring other countries to follow in their footsteps. And with the upcoming United Nations’ climate summit coming to Paris at the end of the year, this is in effect, all the more reason to show the world the environmental benefits of going green.
The government is also encouraging the implementation of solar panels on rooftops because France has lagged behind other European nations, like Germany, Spain, and Italy, in solar power development. France still relies heavily on nuclear power to generate electricity, with nuclear generation making up 83 percent of its energy generation in 2012. In 2014, France had a little over five gigawatts of photovoltaic capacity, amounting to around one percent of total energy consumption. Germany, on the other hand, has 40 GW installed.
The green roof concept is not new
Green roofs have been around for centuries. Early examples are the turfed roofs of the Vikings. Modern green roofs, as we know them today were developed in Germany about 50 years ago. Generally, while green roofs are catching on around the world, there are still skeptics who believe they are too expensive and prone to leakiness.
The exception is Germany, where the green roof industry is worth over $77 million annually. But in Germany, the industry has the backing of the government, unlike other countries. Another exception is the City of Toronto, in Canada. In December 2008, the city adopted the Toronto Green Standard (TGS), formerly know as the Toronto Green Development Standard. Essentially, this standard is all about designing buildings and landscapes that are environmentally friendly.
Section 108 of the City of Toronto Act gives City Council the authority to pass a by-law requiring and governing the construction of green roofs, as an “exception” to the Building Code Act, 1992. The new TGS is still a work in progress, simply because there are no rigid sets of rules or requirements governing the construction of green roofs. So its a matter of trying and finding the best of many methods. Toronto is the only city in North America to have this by-law.