21.10.2015. Le Pavillon Circulaire, Hotel de Ville. fait de materiaux essentiellement recupérés. Arch: Encore heureux
Cyrus Cornut/Matignon 21.10.2015. Le Pavillon Circulaire, Hotel de Ville. fait de materiaux essentiellement recupérés. Arch: Encore heureux

The Circular Pavilion is anything but round, with the exception of its nearly 180 doorknobs. The skin of the 750-square-foot polygonal cafe and event space in Paris comprises a bevy of reclaimed doors, salvaged from a public housing project in the city’s 19th arrondissement, to the northeast. Designed by local firm Encore Heureux and erected in front of City Hall, the temporary structure is named for the aspirational circularity of the lifecycles of its building components.

Reclaimed materials from projects throughout the city make up 80 percent of the open, stick-framed pavilion with a sawtooth roofline and 20-foot-high ceilings. It is a statement about global sustainability, yes—the pavilion was on display during the Paris Climate Agreement talks last December—but it is also an experiment in allowing found materials to drive the design process and to create networks between the building industry and public services. “We are not making trash architecture,” says firm partner Nicola Delon. “It’s very different to take a bunch of trash, put it together, and say, ‘You see?’ ”

The project emerged from Encore Heureux’s 2014 exhibition “Matiere Grise” (“Grey Matter”), which explored the often invisible impacts of a building, such as waste. Partnering with the city, which helped sponsor the exhibition, the firm engaged municipal personnel into realizing the pavilion. Maintenance workers and garbage collectors, for instance, helped divert wooden chairs from the city’s curbside furniture pick-up service.

In the pavilion, architecture acts as a literal intervention, disrupting the everyday waste collection and deposition processes and restricting the architects to design with what could be salvaged. “When we started, we had no idea what kind of material we would have,” Delon says. Insulation came from a supermarket renovation. Baseboards were surplus from Rudy Ricciotti’s MuCEM building, in Marseille. And light fixtures were exhumed from a warehouse owned by Evesa, the company in charge of Paris’ city lighting.

And then there’s the envelope of doors. In May 2015, three months away from the pavilion’s scheduled opening, Encore Heureux got a call from the city: It was removing 400 wooden doors from a 1936 housing project. Immediately, Delon went to see the doors. “Wow,” he said. “They’re perfect.”

His team returned to the studio and began mocking up geometric configurations using pieces of wood cut to match the doors’ proportions. Eventually, they devised a herringbone pattern, with each door angled 45 degrees. They scrapped their initial concept for the pavilion—a tent-like structure made from aluminum panels salvaged from a former high school—and drew a new building with a trapezoidal floor plan and jagged roof punctuated with east-facing skylights. The salvaged doors dictated essentially everything about the structure, Delon says. “It’s impossible to design this building without the doors.”

21.10.2015. Le Pavillon Circulaire, Hotel de Ville. fait de materiaux essentiellement recupérés. Arch: Encore heureux
Cyrus Cornut/Matignon 21.10.2015. Le Pavillon Circulaire, Hotel de Ville. fait de materiaux essentiellement recupérés. Arch: Encore heureux

Encore Heureux worked with the city to time the housing project’s deconstruction with that of the pavilion’s construction, arriving onsite on the day the doors were removed. “We tried to be at the bottom of the building and take them at that time because if you wait, they’re just stuck somewhere or put in the trash,” Delon says. The doors were trucked to a city facility, stripped of hinges and locks, and then shipped to the pavilion site.

To build the structure, the firm again tapped city workers. An open call generated too much interest so the firm developed a rotation system, where laborers cycled on and off the job. Cruard Charpente, the only other private company involved in the project, served as the main timber contractor.


The wood-frame structure sits on steel footings with 4-inch-wide, 10-inch-deep Douglas fir posts and floor joists every 10 feet. The reclaimed doors are screwed to 2-inch-wide wood slats spaced at 2 feet. Behind the doors is a layer of waterproofing membrane on 0.35-inch-thick OSB sheathing, and mineral wool insulation. With the doors coated in 70 years of varnish, and the waterproofing membrane, an exterior finish on the wood was unnecessary. Inside, the walls are finished with 3-foot-by-8-foot painted wood panels, reclaimed from several city buildings.

To account for variances in the sizes of the doors, some of which were significantly warped, the designers left a 0.75-inch joint between doors, filling the gaps with scrap wood painted to match. “The people from the city are good at making the right color because most of the time they work with historical buildings,” Delon says. The angled doors on the upper half of the pavilion were hung first and then trimmed in order to ensure perfect alignment.

Later this year, the pavilion will be deconstructed and moved to its new home along the Petite Ceinture, a former railway that encircles the city inside its once-fortified walls and is being reimagined as a public open space, à la the High Line. Delon hopes the structure and its repurposing of waste have left an impression on the city and people involved. “When you find ways to not waste, you find positive energy,” he says. “Two centuries ago, we’d go to the forest. Now, we go to the city. It’s a change in paradigm.”

Cyrus Cornut/Matignon