We all know what happens when metal is exposed to direct sunlight: it heats up. Now imagine if the rooftops of an entire city were covered in metal and left fully exposed. You just imagined Paris, France.
- 70-80% of Paris’ rooftops (about 110,000 buildings) are covered in zinc metal, which heats up to 80°C when exposed to direct sunlight
- As a result, the city heats up to 10°C hotter than the surrounding areas
A possible solution
In 2020, three friends and architects founded a business called Roofscapes, and they proposed that the rooftops of Paris be transformed into greenspaces and terraces. Here’s why:
- Rooftop terraces would solve the problem of exposed metal roofs that overheat
- The terraces would provide green hangout space and biodiversity in a crowded city that needs more parks, but that has no room for them.
The roadblocks
For such a large-scale project to work, a lot needs to happen:
- A culture shift: Roofscapes says, “A key challenge is to win over architects at the French culture ministry’s Bâtiments de France… whose instincts are more protective than progressive.” They’ve managed to talk with them already, which they consider a win.
- Buy-in: The cost to upgrade the rooftops is estimated at 1,500-2,000€ per square metre, and most of the financial responsibility would likely fall on building residents and owners (though there is a possibility that citizens could draw on government subsidies in the future).
- Logistical hurdles: Most of the rooftops are slanted, meaning building on them would require extra care and planning.
Will it happen?
Only time will tell if Paris authorities and individuals will take the advice of Roofscapes founders, but the company is hopeful.
