France, a country that recently affixed vertical-axis wind turbines to its most famous architectural landmark, is now taking an audacious approach to regulating the energy consumption of new buildings.

As mandated by legislation passed by the French Parliament late last week, the roofs of newly built commercial buildings must be partially covered in vegetation and/or photovoltaic panels. While this is a huge step forward for a largely nuclear-powered nation that lags behind renewables-embracing neighbors such as Spain and Germany, environmental groups pushed for an even stricter law that would have required all new buildings — private homes and apartment complexes included — to have rooftops fully covered in plants.

As noted by Agence France-Presse, French lawmakers decided to ultimately go the less “onerous” route as to not burden building owners and developers with the high upfront costs associated with installing green roofs and solar arrays. Of course, the oft-daunting initial investment involved with harnessing sunlight to produce electricity or topping a building with a lush layer of vegetation eventually pays off with building owners enjoying significant financial savings in the long run.

We’ve seen similar citywide laws enacted elsewhere including Toronto, Copenhagen and Basel, Switzerland’s green roof mandates along with ordinances in California cities like Lancaster and Sebastopol that dictate all new single-family homes to be solar-equipped. For all of France — not just major urban centers like Paris, Lyon and Marseilles — to pass such a law is, well, énorme. And as for Paris, the French capital city will be hosting the 2015 United Nations Climate Change Conference (COP21) come November – the timing on the new building law couldn’t be better.

While a sedum-planted roof and a roof clad in solar arrays may seem like totally different creatures, their end goal is largely the same: to drastic reduce both carbon emissions and our dependence on fossil fuels.

While generally more complex — and expensive — to install and maintain than solar panels since a building usually has to be designed to accommodate layers of dirt and vegetation, easy-on-the-eyes green roofs do have an aesthetic upper-hand over PV installations. They also boast a wide variety of benefits beyond improving a building’s energy performance (read: less reliance on HVAC systems in hot and cold weather) via thermal insulation. As the massive new vegetated roof at the Javits Center in Manhattan recently proved, green roofs serve as veritable wildlife magnets; in urban areas, they act as crucial habitats for birds, insects and other critters that might otherwise be forced out of cities. They also absorb rainwater and, in turn, reduce urban runoff-related woes like street flooding and overworked, aging sewer systems. What’s more, green roofs help to mitigate the urban heat island effect and filter air pollution, an ongoing issue in smog-choked City of Light.

It will be interesting to see if any other European nations — or EU capital cities at the very least —follow in the footsteps of France, always the fashionable trendsetter, with this one. Vive la France! 

Via [The Guardian], [Quartz]

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Matt Hickman ( @mattyhick ) writes about design, architecture and the intersection between the natural world and the built environment.

By law, all new roofs in France must be topped with plants (or solar panels)
Months ahead of the UN Climate Change Conference, French Parliament approves aggressive new commercial building rules.