Viaduc de Millau, Fondation Vuitton, China National Opera... Engineers behind some of the world's greatest civil engineering structures reflect on the future of construction.
Cinq premières minutes du film "Construire".
Project Origins
Initially titled "The Great Builders of Civil Engineering," this documentary project was launched by Sophie Mougard, Director of ENPC (École Nationale des Ponts et Chaussées), to preserve a living record of renowned engineers who had taught at Ponts and were nearing retirement. The primary goal: to ensure no student left the School without knowing the great names and major works associated with it.
When Sophie Mougard left her position in 2022 and was succeeded by Anthony Biriant, the project was championed by Marie Mathieu-Pruvost, Director of Studies, and Aphrodite Michali, Head of the Civil Engineering and Construction (GCC) department.
Having collaborated with Ponts Alumni, the Fondation des Ponts, and the Ponts Student Refugees Association on several audiovisual projects, I was invited to participate in the restricted call for tenders through my production company, ChezFilms.
The main thrusts of my proposal were as follows:
- Tell a story. That's my specialty! The inherent risk with an institutional documentary is that it becomes a collection of interviews arranged chronologically or thematically, but without a real narrative drive. It's essential to build a strong story with a beginning, middle, and end; a narrative capable of captivating the viewer, regardless of their familiarity with the subject. Very early on – it was the first line of my proposal – I indicated that this aspect would be central to my approach.
- Organize consultations at Ponts. This is another common pitfall: trying to define the story too early, sometimes even in the initial proposal, without all the necessary information. For a project of this scale, I believe the first step shouldn't be the story itself, but a collaborative process for writing the story. In other words: planning interviews with key individuals to define the film's core themes and stakes, then establishing validation points to ensure we were moving in a shared direction. The narrative must originate from within the project team; otherwise, the final content risks not being utilized to its full potential.
- In-depth interviews and on-location reports. The interviews would form the heart of the film. Therefore, there was no question of conducting them hastily on a construction site or in an office between meetings. We needed to take the time to delve deeply into the subjects. So, I opted for long interviews (3 hours each) shot in a studio. Using a green screen would allow us to superimpose a subtle graphic reminder of the main structure associated with each speaker's testimony, making it easier for less informed viewers to understand. To energize and illustrate their points, some interviewees would be filmed documentary-style – in their offices, on their construction sites, or, if necessary, using archival footage.
- Create a dialogue. The goal was not to isolate each speaker in their own segment; on the contrary, after being introduced, each engineer would "dialogue" with the others through editing. This often yields more meaningful exchanges than a live debate: in-depth interviews allow each person to freely express their views, taking all the time they need. Then, at opportune moments, these clearly articulated opinions would contrast or reinforce each other on important thematic subjects, advancing the film's narrative.
- A dual deliverable. In addition to the main one-hour film, I proposed providing an additional edit of each interview covering almost the entire conversation. It would have been a shame to conduct such extensive discussions only to keep a mere four minutes from each – a constraint stemming from a simple calculation: film duration (52 minutes) divided by the number of interviewees (between 12 and 15). Thus, for each interview, we delivered a one to two-hour edit that can be viewed on request at La Source, the Ponts media library.
The core idea of my proposal was this: to make the film I wish I had been shown when I first joined Ponts. Often, students choose a Grande École aiming for "the top-ranked" (though this might be less true for Ponts, which attracts construction enthusiasts) without necessarily grasping the nature and challenges of the careers awaiting them. I wanted the film to present to students, from their very first year, the concrete reality of the profession and the questions their predecessors had faced.
Writing the Film
The writing process revolved around two successive deliverables: a "common thread" document to validate the general direction – what are we talking about, which topics to exclude, and what central theme to aim for? – and then a more detailed synopsis, laying out the sequence of topics to be covered.
Several elements fed into this phase:
- Preparatory interviews: Before and during the writing phase, I conducted between thirty and forty interviews, all in person, with professors, researchers, alumni, and professionals from the Ponts ecosystem. The goal was to identify and delve into the must-not-miss key issues. We would briefly discuss their careers and activities, then I would quickly move on to film-related questions: What major evolution have you perceived in your profession? What question would you like to ask the great builders? What under-discussed topic deserves to be in the documentary? Conversely, what clichés about construction, Civil Engineering, or the building sector (BTP) should the film avoid? These discussions also helped identify the individuals to be interviewed for the documentary.
- Including "the next generation": It quickly became apparent that the film would greatly benefit from including younger generations, those Marie Mathieu-Pruvost called "the next generation" – potentially future Ponts lecturers. This was also a wish expressed in many interviews: to celebrate what exists, yes, but also to talk about current transformations, new challenges, and how the younger generation is embracing this heritage. No longer just a historical documentary, then, but a film rooted in contemporary issues, presenting the journeys of several generations of engineers, from the 1970s to the present day, as chronologically as possible.
- A film for everyone: Finally, it was essential that the scientific/technical dimension, while present, never became a barrier to understanding. It should not prevent an average viewer, whether or not well-versed in the subject, from being moved by the life experiences presented: passion, ambition, obstacles, self-questioning, joys, failures, lessons... This human element was to be the heart of the film. Science and technology would be one aspect among others, serving the story.
Drawing from these sources, my goal was then to "weave" the narrative, ensuring that each narrative thread existed, evolved, and intertwined with the others:
- The chronological thread: The film begins in the 1970s and ends today, following successive generations of engineers who testify to the practices of their time.
- The thematic thread: Major issues (the race for gigantism, risk management, the role of architecture, advancements and risks related to technological tools...) are addressed when they are most relevant and benefit from the cross-perspectives of all interviewees introduced up to that point.
- The project thread: Each interviewee's "project focus" is chosen and presented to complement the others, offering both diversity and progression.
- The Transition thread: The ecological transition is ever-present. Initially suggested "implicitly" through practices and certain awakenings, it becomes increasingly central as the film progresses, eventually becoming the focal point.
- The Ponts thread: Subtly woven throughout, these different progressions are analyzed from the perspective of their impact on École des Ponts, both in terms of teaching and its organization.
Filming: Interviews and On-Location Reports
Interviews - The Heart of the Film
Each interview was preceded by a pre-interview, almost always in person. This one to two-hour exchange allowed us to get acquainted, outline important topics, and collectively choose the "project focus."
For the interviews themselves, after considering filming in an external studio, the decision was made to use the studio at École des Ponts. Advantage: a familiar location known to all interviewees – it was crucial for the guests to feel at ease. Disadvantage: the studio wasn't equipped as we wished; this required setting up and dismantling external camera and lighting equipment daily. The initial setup took about three days: location scouting, adjusting camera and light positions, ensuring uniform green screen lighting, etc. Paul Chauvin, our Director of Photography, opted for a main lighting setup called a "Booklight": light from two projectors is bounced off a reflector and then diffused again (the reflector and fabric form an angle, like an open book, hence the name), producing a source that is both powerful and soft.
Fairly early in the preparation, the idea arose to provide interviewees with materials for writing or drawing. We therefore incorporated an architect's table into the setup, continuously filmed by a dedicated third camera. At any moment, they could pick up a pen to visually support their points – a natural gesture for teachers.
A special setup was arranged for Antoine Picon, who participated as a historian. As his commentary served to contextualize the various interviews, his segment was filmed on-site at La Source (the Ponts media library) to distinguish him from the builders.
The technical crew usually consisted of five people: Paul Chauvin (Director of Photography), Chloë Champion (Production Assistant), Matthieu Massard or Vincent Robidou (Sound Engineers), Émilie Bak (Head Makeup Artist), and myself (Director).
Each three-hour interview was structured in three parts:
- Their engineering journey, from their studies and early professional experiences to the major projects that marked their careers.
- Project Focus: Detailed analysis of a particularly significant structure, including its political, technical, and cultural implications.
- Transformation of the profession and advice to students: Their perception of current construction challenges, especially concerning the imperatives of the ecological transition.
These three hours spent conversing with each individual rank among the most interesting moments of my filmmaking career. All the interviewees demonstrated a sincerity, humility, and desire to share that is evident in every minute of the film.
On-Location Reports
To illustrate the interviewees' points and offer a glimpse into their daily lives, we filmed several on-site reports:
- At École des Ponts, we filmed "Design Week," during which first-year students are challenged to build a structure, as well as the graduation ceremony. There, we met two of our interviewees, Bernard Vaudeville (Head of the Civil Engineering and Construction Department) and Marc Mimram (Professor).
- At TESS Atelier d'Ingénierie, we followed its founder, Bernard Vaudeville, who showed us the original notebooks in his office containing the initial concepts for the Vuitton Foundation.
- In Saint-Maur-des-Fossés, we accompanied Sébastien Garnier, Methods Manager for Eiffage, on the construction site of the future Line 15 station of the Grand Paris Express, capturing footage with a ground crew and a drone.
- We visited the Tribunal de Paris (Paris High Court) with Audrey Zonco, Structural Engineer, and Dominique Rat, Architect, to discuss their collaboration on this structure.
- At AREP, we met Raphaël Ménard, Chairman of the Board, who explained the organization of France's largest architectural firm.
- In Cézy, we followed Xavier Cespedes and Mathieu Arquier from Strains, who detailed the future rehabilitation work on the Cézy Bridge. We later met them in their Parisian offices to examine plans and 3D models.
- In Clichy, Anne Chevallier and Patrick Barbier from Kairn agency presented the construction site of a dimension stone hotel, in collaboration with Sylvain Dare, a stonemason.
Archival Footage
The archival footage came from multiple sources, including:
- The interviewees themselves, who provided personal photos and videos.
- Cri Production, the company that documented the construction of the Millau Viaduct, as well as other production companies with period footage.
- INA, Alamy, and other stock image banks.
Funding
To support the film's funding, I was delighted to present and defend the project at "La Nuit des Ponts" (The Night of Ponts), a fundraising evening organized at the Sorbonne amphitheater for the 25th anniversary of the Fondation des Ponts.
This public pitching session was a success, raising over €250k, including over €60k for the documentary, thanks to the support of 111 donors and the participation of Vinci and Setec TPI. The funds were used to finance the remainder of the filming and post-production.
Post-Production
With no less than fifty hours of rushes, editing the film took about six weeks, under the supervision of Pauline Chabauty, head editor.
The rushes were first stored, duplicated, and then synchronized (picture/sound) after each shooting session. Then, separate edits were created to group the different interviews by thematic subjects. These timelines became invaluable resources for finding "the right soundbite at the right moment."
Several versions of the first fifteen minutes were considered until the right tone was found. When Pauline and I weren't working in the same office, we exchanged sequences remotely until we agreed on an opening that "worked and made you want to see more." The whole challenge then was to build a film that lived up to the stakes established.
In parallel, Rémi Boubal, composer, began working on the film's original score. Sometimes, we started with existing music as a reference; other times, simply from the emotion required by the scene. The sound mix was then done by Dominique Ciekala.
After an initial validation screening by the School, held at la Maison des Auteurs de la SACD (SACD Authors' House), some sequences were reworked, then the film was color-graded and mixed before delivery.
Reception
A premiere screening was organized at the Opéra Bastille.
We were delighted to see the film received a very positive reception from the School, both from its commissioners and from staff not directly involved in its production.
As planned, the film will be shown each year to students entering École des Ponts. It is also intended to be shared online soon for wider public viewing.