It will not radically change the face of Paris but it intends to shake up the rules of construction and town planning in the capital for the years to come. After two and a half years of studies and consultation, the draft new local urban plan (PLU) was approved on Monday June 5 by the Council of Paris.

This 3,000-page document will replace its predecessor, adopted in 2006, and will become the bible of urban planning in the streets of Paris. Its entry into force will not take place before the end of 2024, at the end of the public inquiry into use.

If the adoption of a PLU never goes unnoticed, the new document designed by the teams of the municipality marks a break in the main urban planning orientations of the city. Thus, this new PLU is presented as “bioclimatic” by the town hall, which defines this way of doing urban planning as “the fact of designing the city in the service of ecological transition”.

Anne Hidalgo felt that not demineralising the city – reducing the share of materials that are impermeable and reflect little solar radiation, such as concrete – would be tantamount to “collective suicide”. The city lacks shady and refreshing surfaces to cope with the multiplication of hot days.

By 2040, the town hall therefore aims to offer 300 hectares of additional green spaces in the capital, which is severely lacking. The aim is to eventually catch up with the recommendation of 10 square meters of green space per inhabitant established by the World Health Organization (WHO). Paris is far from it today, with 5.8 m2, excluding wood.

Planting trees, reducing felling to a strict minimum, creating parks in former wastelands, permanently sanctuating protected green spaces, opening gardens that are currently inaccessible to the public, are all advanced means of achieving this.

As a corollary to its greening, Paris wants to work on the permeability of its soils. Excluding wood, the city is now 84% waterproof. Among the 300 hectares promised, 110 are reserved for debitumization operations, including 40 hectares of private plots including, for example, residential parking lots.

The IPCC refers to densification as a lever for mitigating the environmental and climatic impact of large urban centers. But Paris is already one of the densest cities in the world. Attached to its objective of offering a maximum of accessible housing, the Parisian municipality assumes that it wants to urbanize the remaining free spaces.

The madness of grandeur in the outlying districts of the capital is over. The new PLU is limited to a height limit of 37 meters. The tall towers that reinforce the intensity of the urban heat effect will therefore cease to grow. Well almost, since previous projects accompanied by the municipality have yet to come out of the ground, including the highly contested Triangle tower, expected to point to more than 180 meters in height.

In the widest streets, the elevation of an existing building will be authorized if it allows the creation of new housing but always within the limit of 37 meters. In the hearts of blocks, the width of the building of new projects will be reduced to facilitate the construction of through housing, more refreshing, and the height will, as a general rule, be limited to 15 meters.

Among other avenues, he cites the role of climatic refuge that the islands of coolness that are the old churches in the Parisian districts could play. It also invites us to ask ourselves the delicate question of the future of Haussmann buildings in the event of runaway global warming. In such a case, the iconic old Parisian stones could not, according to him, do without insulation from the outside.