A growth spurt in green architecture

This article is part of our special Design section about innovative surfaces in architecture, interiors and products.

In the line of climate villains, architecture towers above many. According to the United Nations Environment Program, the building and construction industries are responsible for approximately 37 percent of global CO2 emissions. Three of the most commonly used building materials – concrete, steel and aluminum – generate almost a quarter of all carbon emissions.

But there is progress. The use of renewable organic materials such as wood, hemp and bamboo is expanding. Carbon-absorbing plants and trees are being integrated into architectural design on a larger scale. And even concrete is losing its stigma with the development of low-carbon variants.

Sustainability-minded architects are deploying these materials in buildings that are not only more environmentally friendly, but also look and feel different from the concrete and steel boxes of modernism.

One of the most powerful symbols of the green building revolution – at least in the public imagination – is the plant-covered high-rise. Building designs draped in vegetation can be found in the portfolios of international architects such as Jean Nouvel, Norman Foster, Lina Ghotmeh, Thomas Heatherwick And Kengo Kumamention a few.

However, no one has done more to promote these types of constructions than the Milanese architect Stefano Boeri, who created his Vertical forests.

The original Vertical Forest – a pair of residential towers with facades of around 800 trees, 5,000 shrubs and 15,000 plants – opened in Milan in 2014. Mr. Boeri has since completed a dozen more examples, most recently in Huanggang, China, and the Dutch city of Eindhoven.

“What we have done is use plants, not as decoration,” but as “a kind of biological skin,” Mr. Boeri said. The greenery provides shade and cooling, regulates humidity and absorbs carbon dioxide and pollution. It also serves as a habitat for birds and insects and creates a direct connection between residents and nature.

The buildings are “always evolving and changing with the seasons,” says Mr. Boeri, who has upcoming projects – some entire villages – in various stages of development in locations including Cairo, Dubai and the Mexican resort Cancún.

Some critics have dismissed the Vertical Forest concept as greenwashing or eco-bling, arguing that the environmental benefits are offset by the carbon-intensive concrete and steel needed to support the weight of the trees and plants. Mr Boeri said studies by engineering firm Arup show CO2 emissions increased by just 1 percent as a result of the construction of the Vertical Forest buildings. He added that his company now typically uses precast concrete panels and is considering building with wood where necessary to reduce its carbon footprint.

Mr Boeri acknowledged the limited environmental impact of individual buildings, but emphasized the importance of connecting biodiversity ‘hotspots’ with a network of other green systems. He imagines that there could “certainly” be forest towns in the future.

A metropolis that is taking steps in that direction is Singapore. Policies aimed at bringing nature into Singapore’s city center have produced a cityscape punctuated by green-filled buildings, including some from local firm WOHA.

WOHA’s best-known designs include the recently completed Pan Pacific Orchard hotel, with its expansive garden terraces filled with plantings, and the Oasia Hotel Downtown, a 30-story tower surrounded by a red mesh grid interwoven with nearly two dozen species of creeping plants. vines.

“The permeable residential facade is part of the passive strategies we implemented to cool the building, reduce energy consumption and create a relaxing biocentric space,” said Wong Mun Summ, co-founder of WOHA. Studies have shown that the exterior is up to 68 degrees Fahrenheit cooler than nearby glass-walled structures, he said. If scaled up enough, infusions of greenery could help repair the so-called urban heat islands created by vast expanses of asphalt, concrete, glass and steel.

The heat island effect is a common problem in Asia’s megacities, where rapid development has erased many traces of nature. In Chengdu, China, which is now adding park spaces and encouraging urban greenery, Winy Maas, one of the founders of MVRDV in Rotterdam, is working on a 150-meter office tower with terraced gardens running all the way down from a wooded roof. to the ground.

“This is one of the first tall towers with an outdoor space that is walkable and interconnected,” he said of the design, which includes a sculptural metal mesh fence around the plantings to mitigate potentially damaging rain and wind. “At 500 feet, the wind can dry them out or kill them.”

Carlo Ratti, an Italian architect and director of the Massachusetts Institute of Technology’s Senseable City Lab, who has been chosen to curate the 2025 Venice Architecture Biennale, takes the green-clad high-rise in a different direction. A few years ago in Shenzhen, China, he unveiled a proposal for what he described as the world’s first “agricultural scraper.”

Called the Jian Mu Tower, the 51-story building will be enveloped by a vertical hydroponic farm. Mr. Ratti estimates that his plan could generate enough revenue to feed 40,000 people annually. His studio in Turin is working on prototype modules for the facade.

“At this critical moment, what we architects do is more important than ever,” Mr. Ratti said. “Every kilowatt hour of solar energy, every unit of CO2-neutral home and every calorie of sustainably produced vegetables will be multiplied throughout history.”

Another tool for achieving zero-carbon buildings is one of the oldest and most common building materials: wood. Valued for storing carbon dioxide and keeping it out of the atmosphere for decades, if not centuries, wood is now widely processed into so-called mass timber components, made with compressed, fire-resistant layers.

Among the wooden buildings completed by the New York-based Bjarke Ingels Group, also known as BIG, is a new production facility for the Norwegian furniture company Vestre – “the most environmentally friendly factory in the world,” as Mr. Ingels, who described Danish it – in a forest near Magnor, Norway.

The star-shaped building is covered with a green roof and solar panels that improve energy efficiency. “It’s quite a striking factory to work in because of the warmth and texture of all the wood,” said the architect. He noted that the locally sourced wood even had an attractive smell.

Jeanne Gang is another architect with an affinity for wood. Her Chicago-based company, Studio Gang, just completed an academic building and student housing for Kresge College in Santa Cruz, California. The gently curving wood-frame residential structures are nestled within the densely wooded grounds and their textured wooden exteriors reflect the surrounding redwood trees. Ms. Gang described the material choices as “an ecological and poetic response to Kresge’s stunning environment.”

An equally evocative effect, in a very different context, is achieved in the new terminal for Kempegowda International Airport, in Bangalore, India, designed by Chicago-based Skidmore, Owings & Merrill, or SOM. The terminal is conceived as “a model for sustainable development, but also as a new experience around connecting with nature,” says SOM director Peter Lefkovits. The terminal is notable for the use of specially designed bamboo, which clads the columns and is layered in latticework over the entire surface. ceiling. The design also incorporates hanging plants, lush green walls and water features.

“The idea was to create a building that felt almost like a garden pavilion, with the openness and qualities of filtered light,” said Mr Lefkovits. This was the first time his 88-year-old company used bamboo, a highly sustainable and renewable material due to its rapid growth.

Architects are also turning to other natural, carbon-capturing materials, such as hemp, flax and seaweed. Henning Larsen, an international company based in Copenhagen, recently used thatch to create the very first thatched facade for a new primary school in southern Denmark.

The choice of thatched roofs, which gives the building’s exterior a slightly rough, organic texture, is inspired by the local tradition of using wheat as cladding, says Jakob Stromann-Andersen, who manages Henning Larsen.‘S sustainability and innovation team. Everything about the horseshoe-shaped building’s design, he added, was intended to “strengthen the connections between the classroom and nature,” including a walkable green roof that slopes downward and blends into the landscape at both ends.

Organic fibers are also processed into composites such as hemp concrete or mixed into bioresin panels that are durable enough for building facades. These types of materials are seen as essential in the race towards more sustainable buildings, along with recycled bricks and low-carbon concrete, both of which are increasingly used. Researchers are also experimenting with adding carbon-absorbing algae to concrete to achieve mixtures with net-zero or even negative emissions.

“We cannot simply rely on natural materials, because there is simply not enough wood and bamboo to build the entire stock of buildings we need,” said Yasemin Kologlu, head of SOM’s Climate Action Group. “We cannot continue to build in the way we are doing now, but there is no silver bullet. To get there, it has to be a culmination of perhaps more than thirty different strategies.”