More vegetation has been incorporated into the Piechaud island project. – 4A / Bordeaux City Hall
- The ecological city hall of Bordeaux has developed a label to green the construction of future housing and offices in the city.
- It promotes the use of bio-based and local materials, the development of outdoor spaces and natural ventilation.
- Within two years it will be integrated into the PLU and by then, professionals in the sector will be accompanied to apprehend it.
Gone are the monumental architectural achievements on the banks of the Garonne and the recourse to international signatures all the time. The new ecological municipality wants to turn the page on the Juppé era, by concentrating all its efforts on the ordinary constructions of the city, which are the housing and the tertiary sector. The main tool it has just acquired to make buildings more virtuous in terms of ecology is the Bordeaux frugal building label, the 42 criteria of which have just been unveiled.
Materials within a radius of 200 km around Bordeaux
The production channels for biobased materials such as earth, straw and brick are not yet structured. That of wood has recently been industrialized for construction. “All the wooden facade panels are made with maritime pines from the Landes”, points out Bernard Blanc, deputy mayor of Bordeaux in charge of town planning. The idea is to ban concrete as much as possible, to decarbonize real estate production, without completely renouncing it when it is essential. “For the base of a car park, I have to use concrete to meet a regulatory constraint. But for the upper floors, I have to look for biobased materials, ”illustrates Bernard Blanc, for example.
Outdoor spaces, ventilated housing
With global warming, the city is highlighting the important issue of “protecting the building from extreme heat”. The implementation of “natural ventilation to lower the temperature at night” is one of the central criteria of the label pointed out by the town planning assistant. He also insists on outdoor spaces attached to each accommodation. “We need to have an exterior, a shared garden for example in a residence to ventilate, especially during confinement,” he points out. Of the fifteen demonstration projects on which the label has been tested, thirteen of them are old warehouses or sheds with no heritage value. On 80,000 m2 of floor space in total, on entirely artificialized sites, around 25% of open ground was found on average, thanks to project work through the prism of the label.
“Another era”
Visually, one should not expect a typical Bordeaux building but rather an assumed choice not to run after the appearance of the 18th century facades which have earned the city a Unesco classification. “Alain Juppé absolutely wanted blond stone because he believed that Bordeaux had been invented in the 18th century, mocks Bernard Blanc. We are not against that but we no longer know how to build that way. We are in another era and the ordinary city, which is constantly on itself, we no longer make it with 18th century facades. “
For the moment, this label is not legally enforceable but 22 of the 42 criteria must be taken into account when submitting an application for a building permit. Still, this label should be integrated into the next PLU in two years and that the sector is asked to take the fold by then. It is also for the City to take the time to support professionals to help them absorb the additional cost, estimated at 10 to 15%, with this new way of building the city. If the building concerned is frugal, discussions with developers and builders promise to be copious.