It’s a petty quarrel in the heart of Paris. Or rather roof. The roofers-zinc workers of the capital have been struggling since 2014 to register their know-how as a UNESCO World Heritage Site. They would not refuse a spotlight allowing them to promote a profession that is struggling to attract. Bet (partially) successful: after having preferred the traditional baguette during the previous session, the Ministry of Culture submitted, last March, their candidacy for the 2024 cycle.
If the profession becomes recognized, its raw material, the zinc roofs which contribute to the fame of Paris throughout the world, will be too. CQFD. Except that they represent an aberration at a time when temperatures are constantly rising, notes senior civil servant Franck Lirzin, former adviser to Emmanuel Macron at Bercy, in his essay Paris facing climate change, released last year. “They are not adapted to high temperatures and become an oven during heat waves”, confirms Vincent Viguié, researcher at the International Center for Research on the Environment and Development (Cired). “It’s outdated, obsolete”, abounds the architect Bruno Bouchaud.
The debate between heritage protection and adaptation to climate change is not limited to zinc roofs and their shades of gray. It concerns all the Haussmannian, that is to say almost a third of the Parisian buildings. A major challenge for the capital: energy renovation is one of its main levers for achieving the objective of carbon neutrality by 2050. The building sector represents 40% of energy consumption and 20% of carbon emissions. greenhouse gases (GHG), according to the Regional Court of Auditors. To push for renovation, the government is increasing financial incentives – “MaPrimeRenov” in mind. Recently, the Minister of the Economy Bruno Le Maire announced that the housing savings plans (PEL) could be released for the financing of energy renovation works.
“Paris might have to live after Haussmann”
A goodwill that solves nothing of the puzzle embodied by these many typical buildings of the City of Light, classified and therefore framed by (very) strict regulations. This is discouraging when starting major projects. “There is a cultural blockage on this subject”, deplores Vincent Viguié. This paralysis “imposes itself on us like a tsunami, confirms Bruno Bouchaud. Paris considers its Haussmannian heritage as being an immobile and intrinsic value, forgetting a little that Paris lived before Haussmann, and that Paris should perhaps live after Haussmann”.
The facade of a Haussmann building in Paris.
© / afp.com/BOYAN TOPALOFF
The defenders of an “already there”
Not everything is to be thrown away in the work of the baron, who modernized the French capital at the request of Napoleon III between 1853 and 1870. “There is no need to insulate a Haussmannian building from the outside, which is very well designed “, notes the architect. Regarding the black spots, namely the exterior joinery, the attic and the roof, more or less visible solutions exist: high-performance double glazing, real insulation… Bruno Bouchaud lists the “completely satisfactory” possibilities on paper and that he should be put to the test: cover the zinc with velums for part of the year or green the terraces (the upper part of the roof). “It would not distort the building from the street. Admittedly, the view from the high points – the Sacred Heart or the Eiffel Tower – would be modified. But we would see a vegetated Paris there.”
Vital not to cook under the roofs in summer, this plan remains hampered, according to him, by the conservative vision of the defenders of an “already there”. He cites the Commission du Vieux Paris, a counter-power in terms of heritage that Anne Hidalgo wanted to reform, and the architects of the Buildings of France (ABF). “In as part of the Paris at 50 degrees report, I was interviewed by their representatives who expressed a cautious, therefore immobile vision. We have not yet become aware of the imminence of the problem”, he regrets. “You can never be too careful, answers Simon Texier, secretary general of the Commission du Vieux Paris and professor at the University of Picardy Jules Verne. The steamroller of the renovation is running but we do not give an overall opinion. Requests are studied on a case-by-case basis, in discussion with the Paris Climate Agency (APC). There are possibilities for insulation, we are looking for the least violent option for the integrity of the building.”
rules to write
The Parisian adviser Alexandre Florentin (Génération Ecologie) led the mission in question and was able to measure the balance of power at work. On the one hand, the partisans of rapid urban changes – climatic emergency obliges – but who activate in dispersed order, without real weight. On the other, the members of the said Old Paris Commission (whose opinions remain advisory but often followed) and a dozen architects with great decision-making power. “Between the start and the end of the mission, I felt a change in the position of the ABFs”, he nuances. In the final report, Frédéric Masviel, the director of the Parisian section, defends the importance of a “notion of rules to be written” to “agree on the future of the evolution of a city”. One of his suggestions was also taken up in the recommendations of Paris at 50 degrees: the organization of a conference with all the stakeholders of the capital to bring out a “coherent and aesthetic adaptation project of the Parisian building” .
All the interlocutors questioned plead to sit around a table and discuss – “with a clear objective of results”, specifies Alexandre Florentin. And “without dogma”, maintains Bruno Bouchaud. Because if the technical solutions are known, it remains to be seen where to place the cursor. The scale of the task is immense and time is running out. “We have to increase the pressure, insists the elected official, create a collective of the inhabitants of the top floor, carry out lots of tests and allow ourselves to crash”. Above all, put the means into it.
Because as often, the best ambitions come up against budgetary realities. In its latest annual report, the High Council for the Climate agrees that “the policies implemented do not make it possible to initiate a sufficient number of effective complete renovations. Several improvements in 2023 have made it possible to facilitate global renovations, without however marking a strong inflection. The funding remains insufficient, both in terms of amount and visibility”. The architect Bruno Bouchaud mentions a series of measures to be taken: the implementation of an environmental Marshall plan, more tax incentives, the simplification of certain standards… Or the creation of a “multi-skills” commission similar to the one put in place to rebuild Notre-Dame Cathedral. “We are only at the beginning of a reflection,” he concludes. The zinc roof still has beautiful (and hot) days ahead of it.