Global ambition: ‘Reinventing the DNA of the built environment’

Imagine a small house whose exterior is covered with planters full of ripe radishes, carrots, and lettuce. Indoors, another wall of plants stretches floor to ceiling. Their microbe-rich roots capture harmful air pollutants. If you touch the plants, beneficial microbes cross to you, possibly prompting a subtle shift of your own microbiome toward better health.

The house captures rainwater, purifying it on-site with solar energy. The entire structure is made of flaked-wood slabs that are strong enough to replace steel. Unlike steel, though, these slabs sequester carbon. The building can be taken apart, the slabs re-used elsewhere, or their carbon released to other organisms that keep it from re-entering the atmosphere. 

Houses like these may become commonplace — even urgently necessary — as the world’s resources grow scarcer, the planet warms, and the climate weirds. So the Yale Center for Ecosystems in Architecture (Yale CEA), a transdisciplinary research enterprise based in the School of Architecture, is rethinking global sustainability for the 21st century. 

By combining novel science and technology with vernacular building principles, center researchers aim to enable a truly sustainable built environment, one that that not only provides shelter but also fosters healthy ecosystems and even bends the CO2 curve.

“Our [current] infrastructural model is bankrupt. It's doesn't work. It's neither resilient nor life-supporting,” says Anna Dyson, the Hines Professor of Sustainable Architectural Design, who also holds appointments in the schools of Architecture, Environment, and Nursing. “What we seek to do is partner with [emerging economies] to forge a 21st-century way of resiliently coexisting with nonhuman living ecosystems and supplying our requirements for energy, water, and materials sustainably.”

Founded three years ago by Dyson, Yale CEA brings together faculty, research scientists, and Ph.D. students from multiple schools, alongside industrial collaborators; collectively, their affiliations include the Yale schools of Architecture, the Environment, Medicine, Nursing, Public Health, Management, Engineering, Arts and Sciences, and Law. 

Instead of a traditional approach that sends raw building materials on a linear journey through consumption and waste, Yale CEA faculty instead train students to work with natural systems, so that resources, energy, and life flow into, within, around, and away from a building. Everything is multifunctional; nothing is wasted. A system that captures sunlight to reduce indoor lighting needs, for instance, may also use the warmth to heat and purify water. A wall supports a microfarm, whose ecoystems are designed to interact with human beings and promote health. Building materials keep carbon out of the atmosphere while providing structural support. Such buildings are largely self-sufficient, yet they constantly interact with their occupants and their surroundings in ways that aim to leave both better off.

“We go all the way into the lab and work alongside physicists, material scientists, and engineers to look at how we can manipulate energy and material flows in different ways, and how we can satisfy multiple technical, functional, aesthetic, and cultural criteria simultaneously,” Dyson says. “If we can do that, we can deliver systems that have a lot of value to society, and we can start to move towards on-site net zero energy, water, et cetera in a real way.”

“I tell students all the time, ‘You are so lucky to be entering the field right now, because architecture has blown wide open,’” says Alan Organschi, an architect, senior critic at the School of Architecture, and principal of the New Haven firm Gray Organschi Architecture. “It’s no longer sitting at a desk and drawing skyscrapers or houses. It's thinking systemically about what we consume and where it's going to go at the end of its life.

“Suddenly [students are] able to see buildings, not as permanent objects in the landscape, but as technological objects that litter the landscape [and] that must be accounted for. That's an educational paradigm shift.”

Material advances

This shift comes not a moment too soon. Globally, buildings account for 40% of global energy use and 25% of water consumption, according to the United Nations Environment Programme (UNEP). The built environment already accounts for one-third of greenhouse gas emissions, the UNEP estimates, even as urbanization accelerates all over the world.

But we could be designing to remedy the situation. 

Water purification, for example, is a crucial function a building could play. Dyson and Jaehong Kim, the Henry P. Becton Sr. Professor and chair of Chemical & Environmental Engineering, are developing a solar water disinfection window unit that could provide clean drinking water and safe disinfectant products like hydrogen peroxide to people who otherwise lack safe access to both. In addition, this unit can provide power and hot water, as well as reduce indoor glare and heat gain inside the household. 

Mandi Pretorius, a Ph.D. student who is working with Dyson and Kim on solar disinfection, points out that the new ways of thinking are in some ways premodern: “less [about] centrality and authority and control and more about distributed decentralized processes,” such as water treatment that doesn’t depend on municipal facilities. 

Then, too, there’s what we build with. New building materials may not only be lighter and more renewable than steel and concrete but also could remove carbon from the atmosphere and safely store it, Organschi says.

For years, he explains, the “standard sustainability story” has held that most buildings’ life-cycle energy consumption occurs during the years when they are in active use. That has led to an emphasis on creating efficient, well-insulated structures. 

But up-front resources and construction — the steps that take place before anyone ever steps into the building — account for a substantial share of emissions, Organschi has found. So it’s crucial to take that “embodied carbon” stage into account.

Steel and concrete, for instance, are resource-intensive. But a promising alternative is engineered wood products. With wood harvested from sustainably managed forests where soil health and high biodiversity are maintained, we could store vast amounts of carbon in our buildings. Humanity’s very homes could serve as a collective global carbon sink. Another type of construction materials that can safely tie up carbon in buildings is made of waste from agricultural products. These relationships undergird what is called a circular material economy.

As a bonus, interiors made with wood products rather than mineral derivatives like drywall can buffer moisture and heat levels and may even support human health — effects that Organschi is studying with collaborators from Yale School of Public Health and others. 

Living indoors

The health effects of the indoor environment are a central CEA concern.

“We're reinventing the DNA of the built environment,” Dyson says — and, with grants to study the genetic material of indoor microorganisms, she means it literally. 

Humanity has spent most of its history outdoors, she points out, a situation that changed comparatively recently. 

“With indoor environments, we're cutting ourselves off from a biodiverse ecosystem within which we co-evolved,” Dyson says.

That’s something architecture Ph.D. candidate Phoebe Mankiewicz ’24 is working to understand. 

Trained as a biologist, Mankiewicz calls herself Yale CEA’s “green sheep.” She is investigating how bacteria in the roots of indoor plants might affect indoor air quality. The right mix of plants and microbes could reduce air pollutants, regulate humidity and temperature, and influence human health by colonizing our bodies, releasing beneficial compounds into the air, or calming our nervous systems.

Such complex territory remains barely explored by biologists, let alone architects, according to Mankiewicz. With experience in traditional science labs, she is designing experiments with different light levels and plant growth media, such as nutrient-rich liquids or potting mixes, at Yale School of the Environment. Working with the School of Public Health faculty member Krystal Pollitt, Mankiewicz will measure how these plant systems interact with indoor pollutants, like formaldehyde emitted by carpeting.

“In no other program would I be allowed to look at biology and plant ecology, physiology and soil science, and air quality chemistry all together,” said Mankiewicz. “I wouldn't get to measure all of these variables, which are so inherently interconnected.”

Understanding how people’s bodies react to a space can help architects build for better health. Yale CEA’s Socioecological Visual Analytics (SEVA) tool collects data from sensors monitoring the indoor environment, such as carbon dioxide levels, and physiologic measures like heart rate, explains a center co-founder Mohamed Aly Etman, a research scientist at the School of Architecture. He uses SEVA with Yale School of Medicine researchers to better understand how to design healthful interiors.

A place to call home

In 2018, the School of Architecture, Yale CEA, and Gray Organschi Architecture showcased their ideas with a prototype “tiny house” in New York City on United Nations (UN) Plaza, one that powers itself as well as nourishing its residents. Built by JIG DesignBuild, Organschi’s construction company, of sustainable materials, the 22-square-meter Ecological Living Module (ELM) generated solar energy and captured daylight to replace electric light through a novel system that uses less than 1% of the toxic, non-renewable semi-conductor materials found in conventional solar panels. The little building, designed by Gray Organschi Architecture, also harvested and purified rainwater and remediated its own indoor air, while graywater irrigated a micro-farm attached to the outer walls.

Such near self-sufficiency is crucial, for example, for refugees living in cities that prohibit them from accessing local infrastructure. But it’s also key in places that lack pre-existing infrastructure altogether. Yale CEA aims next to partner with UNEP to build an ELM in a town in Guatemala, one of many impoverished communities that are being devastated by emigration. There, the solar-water disinfection and farm walls could demonstrate novel methods to provide residents with safe drinking water and a nutrient-rich diet.

The approach to the building is replicable, if not necessarily its materials or final form, Etman said. Those details will vary depending on where in the world it’s built. In his home country, Egypt, for example, such a house could harvest more solar energy — an abundant resource there — and it would also have to accommodate a larger family, in keeping with cultural norms in that region.

Projects like this allow for the kind of urban and ecosystemic testing and experimentation that large commercial buildings in developed cities don’t, Dyson said. Yale CEA continues to collaborate with the United Nations.

“The built environment process is conservative and risk-averse. The components often depend on each other, so it's hard to make the kind of wholesale change we need for a sustainable future,” she says. “But small-scale demonstrations permit us to show entirely new systemic models and could lead to radical change by showing what future cities could be.”