
“What we are doing is using shade, humidity, wind, and water to lower the temperature in the heart of Paris,” explained Brussels-based landscape architect Bas Smets, who has won an international design competition to redesign the landscape around Notre-Dame cathedral in Paris. Founder of Bureau Bas Smets (BBS), Smets is leveraging nature-based solutions, including a significant expansion of green space and a scrim of water, to cool the cathedral and protect it from future climate impacts.

In 2019, the cathedral caught fire, causing the destruction of its 150-foot-tall spire and interiors. The reconstruction of the 760-year-old medieval Catholic cathedral, a UNESCO World Heritage site, has started, but the organizers of the competition, which include the Paris city government; Diocese of Paris; and Public Establishment, the conservators of the cathedral, saw the need to further leverage the landscape to preserve the monument for future visitors and worshippers.
Smets is leading a team on the $50.3 million project that includes Paris-based firms GRAU, an architecture and urbanism firm, and Neufville-Gayet Architects, an architecture firm specializing in historic buildings. Together, they are re-imagining the visitor experience of the gothic cathedral while also adapting the site to rising temperatures. Their goals align with Paris’ Climate Action Plan, which aims to reduce heat islands throughout the city.
Smet’s team will ring the cathedral in trees that will provide shade and cool the air, creating a micro-climate on Île de la Cité, the island in the midst of the Seine River where the cathedral is found, and its immediate surrounding area. The form of the existing rectangular square in front of the cathedral will be simplified, creating “a perfect rectangular form” to make it clearer and more usable, edged with a new canopy of trees, Smet’s firm states.
According to The New York Times, the Jean XXIII Square, a park behind the cathedral, will be connected with new green spaces that extend to the edge of Île de la Cité. This new park will link with gardens on the cathedral’s southern edge, creating a 1,300-foot-long green space planted with 131 new trees. The Architect’s Newspaper also notes that Île-de-France Square will also be integrated into the new plans. Throughout the expanded site, trees will increase by nearly 35 percent, in places layered behind existing trees, so as to not obstruct protected views.


Water will also be used to support that new micro-climate. Smets’ team plans for a 5-milimeter (one fifth of an inch) scrim of water in the forecourt of the cathedral in the summer. The water element will help cool the facade of Notre-Dame while bringing a shimmer to visitors’ photographs.
At the same time, Smets is rethinking the entire visitor experience and creating new pedestrian connections to the cathedral. A parking lot under the cathedral will be transformed into a welcome center and connect with an existing archeological museum that will now be accessible via a new passageway off the quay along the Seine. Currently visitors need to access the cathedral via stairs from the quay.


The New York Times reports that at a press conference, Father Drouin with the Diocese said: “I am very pleased that the tragedy of the fire will enable us to recreate physical and symbolic ties between the capital and its urban environment.”
While leading with climate, the landscape architecture address issues holistically. “The urban figures, such as forecourt, square, square, alignment and banks, are all present around the cathedral, but in a fragmented way. The project reveals the quality of each place and rethinks each of these figures from the double angle of the collective and the climate,” Smets told Paris.

And as he noted to Wallpaper magazine, “we wanted to make a nuanced composition. You’ll walk in, sit, stay, go underground, open towards the river, emerge close to the entrance…More than giving a form, we are giving an experience.”
The restoration of the cathedral is expected to be completed by 2024, when Paris hosts the summer Olympic games, while the landscape redesign is scheduled to be finished by 2027.
For those in the Washington, D.C. area, also check out the National Building Museum’s augmented reality tour of Notre-Dame.
Heating and cooling make up a significant amount of energy costs. Intelligent curation of architecture and landscaping can help provide insulation against extreme heat and cold, reducing the amount of energy necessary to make an environment comfortable.
Great post!