When Tristan Le Lous and his brothers Briac and Guirec bought Bordeaux third-growth Château Cantenac-Brown in Margaux this past December, they fulfilled a long-cherished dream to own a top wine estate. They'd grown up in Burgundy, their grandfather's cellar generously stocked. "We've always been passionate about wine in my family," said Tristan Le Lous.
They are also passionate about sustainability, terroir and being part of a greener future. So when they made plans for a new cellar they decided to combine an environmental approach with modernity and design. "I've been interested in ecologically responsible buildings and architecture for a long time," said Le Lous, 40, a father of two who holds degrees in molecular genetics, agronomy and business.
His quest led him straight to French architect Philippe Madec, a champion of eco-friendly building who was made an Officer of the Legion of Honor for his work in sustainability. Madec, who co-authored "Manifesto for a Happy Frugality," promotes combining sustainability with design to reflect an evolving idea of what is modern and beautiful. "The new generation understands this," Madec told Wine Spectator. "We have to imagine there will be a new aesthetic."
Madec answered the Cantenac-Brown team's challenge to build green with a unique design for a modern, carbon-neutral winemaking facility, its vault built with raw earth, an ancient method of packed dirt, and compressed stabilized earth blocks (CSEB) capable of supporting a roof. It is believed to be the only load-bearing project of this kind in the world, putting it at the vanguard of green building choices.
"We are doing something that is really rare," said Madec, who has advocated for sustainable architecture since the 1980s. This project, he said, came down to three key points. "For the building, we are not using cement. We are going to build a vault with CSEB. And we are using the temperature of the ground to cool the cellar."
The choice of materials is integral to the overall environmental footprint of the build. "I only use earth, wood and stone," said Madec. "It's a long debate, but reinforced concrete is one of the worst materials on earth and one of the reasons for climate disorder. Air travel contributes 2 percent of greenhouse gases and the production of reinforced concrete contributes 7 to 9 percent."
The dimensions of the build combined with the needs for producing fine wine also influenced the choice in materials, such as the need to keep the cellar cool. "Philippe proposed terra cotta bricks at first, but the thermal inertia was not as good as the raw earth construction," said Le Lous. If they'd chosen the terra cotta, they would have had to reduce the space by lowering the ceiling or use air-conditioning to maintain the perfect temperature for wine.
An important factor in calculating for temperature control inside the cellar was the use of a climatic well, a geothermal air-to-ground heat exchanger. "Below the surface, around [13 feet] in depth, the temperature is constant, and it is [55° to 57° F]—perfect for wine. So we take the air cooled by the ground, and when it enters the winery, it has the good temperature," explained Madec. "Because the winery is made with earth, there is good inertia and the temperature will be stabilized."
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They've also chosen to integrate the new cellar within an existing building, a decision that dramatically lowers the impact of the build on the planet. "Forty percent of emissions in the world come from construction," said Madec. "And 60 percent of the garbage is from construction—that's why we're using the existing buildings. We will preserve the character of the estate, and there will be no reconstruction, no throwing away."
The existing walls will be insulated using organic straw and CSEB. The wood used will be untreated and sourced locally in the region. The roof will incorporate rain water catchment, and gray water will be recycled. Solar panels will make the winery energy-positive.
"We've paid the highest respect to the environment, using the most advanced techniques at the moment, in terms of sustainable design, in order to preserve the terroir while continuing to adapt and push forward agricultural methods," said José Sanfins, longtime general manager and winemaker.
Inside the cellar, Sanfins will have all the usual bells and whistles—gravity-flow vinification and a small army of vats matched to plot sizes for precision blending. They plan to break ground in April and finish in time for the 2023 harvest. Le Lous estimates the initial cost to be 10 percent more expensive than a traditional concrete build, but they'll save money down the road as they won't need air-conditioning.
Le Lous and Sanfins told Wine Spectator that the cellar project is part of their overall vision for the 220-acre estate, a green ethos that embraces the vineyards, the new cellar, and the estate's historic biodiversity. When Scotsman John Lewis Brown created the estate in 1806, he planted an arboretum. Today the forest covers 70 acres.
"We want to maintain and develop the collection of trees and create again the garden as it was planned initially," said Le Lous. "Our sequoia is 200 years old and [131 feet tall]."
And in a wink to Lewis Brown, they've imported 30 Scottish sheep to maintain the park, eschewing lawn mowers. "Of course we've taken precautions to make sure the sheep don't eat the vines," said Le Lous.