Quelle ville demain ? Avec Christian de Portzamparc

At a time when major cities must reconcile density, diversity, and sustainability, architect and urban planner Christian de Portzamparc—the first French winner of the Pritzker Prize and a pioneer of the open block concept—shares his vision of a city in perpetual evolution. Between historical heritage, flexible uses, and reimagined mobility, he outlines the contours of a human, luminous, and resilient urbanism, where the street regains its place and neighborhoods thrive 24/7. This is essential reading for those involved in real estate, urban planning, and land development. Key quotes and central ideas 1. The city as a living organism: sedimentation and flexibility “The city is like a human being: you can’t predict exactly how it will evolve. We build on what already exists, layering different eras. It’s a wise and human beauty.” — Christian de Portzamparc The end of the "clean slate": Cities don't reinvent themselves from scratch, but adapt by integrating what already exists (e.g., brownfield redevelopment, office conversion). Example: In Massy (Atlantis), a dense, mixed-use neighborhood (housing, offices, shops, cinema) was created around a train station, proving that mobility generates urban life. Flexibility of spaces: Buildings must be able to evolve (e.g., converting offices into housing). Challenge: Anticipating demographic and economic changes (e.g., growing families, teleworking). 2. Urban diversity: avoiding ghost towns "La Défense at 7 p.m. is deserted. We need to mix uses so that neighborhoods are vibrant at all hours." “— Christian de Portzamparc Mixed-use development: Housing + offices + shops + leisure facilities in the same neighborhood (e.g., the Presqu’île in Grenoble). Social diversity: A political challenge, as mayors fear alienating their constituents. Successful example: Masséna district (Paris): 30 architects collaborated to create open blocks with sunny courtyards and shared spaces. 3. Mobility: the lifeblood of the city of tomorrow “The Grand Paris Express, with its 70 stations, will transform the region. Dense and vibrant neighborhoods will emerge around each station.” — Christian de Portzamparc Public transportation: Stations are becoming development hubs (e.g., Massy, ​​Grand Paris Express). Controlled density: Building high (6-10 stories) to free up ground space (gardens, squares). Cars and Active Mobility: Cars remain necessary, but active mobility (tram, bicycle, walking) must be prioritized. Example: In Grenoble, a large pedestrian avenue will connect the scientific research area (Presqu’île) to the city center. 4. The Open Block: An Alternative to High-Rise Buildings “Le Corbusier wanted to kill the street. I want to save it by bringing light and life into the neighborhoods.” — Christian de Portzamparc Principle: Preserve streets and avenues, but open up the blocks to avoid the “dark corridor” effect. Offset buildings to create light perspectives and shared green spaces. Advantages: Natural light in courtyards. Architectural diversity: Avoid the monotony of high-rise buildings. Flexibility: Allow for future extensions or transformations. 5. Zero Net Land Take (ZAN): A Realistic Challenge? “Zero net land take is frightening. We need to find a balance: densify without suffocating, build without paving over everything.” — Christian de Portzamparc Solutions: Build upwards (10 stories max) to free up green spaces at ground level. Reuse brownfield sites and parking lots (e.g., convert vacant offices into housing). Combine density and nature: Green roofs, green corridors, community gardens. Example: Project for La Défense: Create a shopping avenue at the foot of the towers to revitalize the district, rather than just a park. 6. La Défense and Business Districts: How to Reinvent Them? “La Défense can become a true urban center if we introduce mixed-use development, shops, and housing.” — Christian de Portzamparc Diagnosis: Neighborhoods that are too concrete, monofunctional (offices empty in the evening), and disconnected from the city. Teleworking and a focus on biophilia are challenging the high-rise model. Proposals: Introduce housing and shops on the ground floor. Create pedestrian avenues (e.g., a Rue de Rennes at the foot of the towers). Sustainable mobility: Trams, bike paths, and vibrant public spaces. Example: The Sisters Towers (La Défense) will include a hotel and a panoramic restaurant to attract a diverse population. An Agora Managers Group event Networking-Media-Training https://www.agoramanagers.fr/