Twenty years ago, the Seattle, WA-based Cascadia Green Building Council (CGBC) introduced what has become one of the most rigorous and responsive building standards in the world. At a time when beyond-code, industry-driven standards were proliferating, Jason McLennan, CEO of the CGBC, wanted to move the industry beyond the paradigm of “doing less harm” and toward doing “more good.” Rather than imagining a world that was merely a less-bad version of the one we already had, he posed a simple and profound question: “What does ‘good’ look like?”

Living Building Challenge (LBC) basics

McLennan’s “more good” took shape in the metaphor of a flower. What would a building look like if it functioned as elegantly and efficiently as a flower? How would our built environment transform if it lived entirely on the energy it could produce from the sun, gathered all the water it needed from rain and snow, created no waste that could not be reused, nourished other living things, adapted to its local climate, and stood as a thing of beauty in its own right?

The LBC has translated these questions into seven performance areas, known as the “petals of a flower”:

• Place—Responsible site selection, habitat protection and connection to community.

• Water—Collecting, treating and using water on-site while managing wastewater without conventional sewer systems where feasible.

• Energy—Producing 100 percent of a building’s energy needs from renewable sources generated on-site.

• Health and happiness—Promoting occupant well-being through daylight, fresh air, nature and healthy indoor environments.

• Materials—Using safe, responsibly sourced materials while avoiding a list of harmful chemicals known as the “Red List.”

• Equity—Creating inclusive, accessible and socially just spaces.

• Beauty—Inspiring people through thoughtful design and fostering environmental education.

The Living Building Challenge has had a significant influence on regenerative architecture and sustainable design worldwide. Although relatively few projects have achieved full certification because of its stringent requirements, many architects and developers use its principles to guide high-performance building design. It has also inspired related certifications focused on individual performance areas, such as the Zero Energy, Zero Carbon and Core Green Building programs administered today by the International Living Future Institute (ILFI), the organization that now oversees the LBC.

In this way, the Living Building Challenge represents a shift from sustainable design, which focuses on reducing negative impacts, to regenerative design: creating buildings that actively improve environmental and human health.

The Red List: Building for health

When we buy food at the grocery store, we expect it to be safe to eat. When we fill a glass with drinking water, we expect it to be clean. When we take medicine, we trust that it has been carefully tested.

But how often do we ask a much simpler question: Are the buildings we live, work and learn in made from materials that are safe for us?

Most of us rarely think about it. We notice whether a house is warm in winter or cool in summer. We admire beautiful architecture, spacious rooms and large windows. We think about the cost of construction and the amount of energy a building uses. And hidden behind the paint, beneath the flooring, above the ceiling, and inside the walls are hundreds of different materials that we never see.

For generations, many of those materials were chosen because they were inexpensive, durable, or easy to manufacture. Only later did scientists discover that some contained chemicals that could harm people or damage the environment.

History offers many examples. Asbestos was once praised as a miracle material because it resisted fire, until it was found to cause serious lung disease. Lead paint brightened homes for decades before its effects on children’s developing brains became widely understood. Other chemicals, used in plastics, insulation, adhesives and furnishings, have since been linked to cancer, hormone disruption, breathing problems or pollution that can last for generations.

The lesson is clear: A material can seem useful today and still prove harmful tomorrow.

Recognizing this challenge, the Living Building Challenge introduced what it calls the Red List—a carefully researched list of chemicals and materials that should be avoided whenever safer alternatives exist.

The name is easy to understand. Just as a traffic light tells us when to stop—provided we honor that red light—the Red List tells architects, builders, and manufacturers to stop using materials known to pose serious risks to people or the environment.

This idea reflects a simple principle: The healthiest buildings begin with healthy ingredients.

Think about preparing a family meal. Even the finest recipe cannot produce healthy food if some of the ingredients are unsafe. The same is true of buildings. Solar panels, energy-efficient windows and beautiful design are important, but they cannot fully protect the people inside if the materials themselves release harmful substances into the air they breathe.

Modern life is largely lived indoors. According to the U.S. Environmental Protection Agency, Americans spend roughly 90 percent of their time inside buildings—sleeping at home, learning at school, working in an office, or recovering in a hospital. The air around us is shaped not only by ventilation but also by the materials that surround us.

A healthy building should do more than protect us from rain, wind and cold. It should protect us from unnecessary exposure to harmful chemicals as well.

The Red List reminds us that our choices affect people we may never meet. Workers who manufacture building products deserve safe workplaces. Communities near factories deserve clean air and clean water. Future generations deserve buildings whose materials can be reused or safely returned to nature instead of becoming hazardous waste.

So the Red List asks us to think beyond the walls of a single building. Every material has a story: it comes from somewhere, is made by someone, and eventually goes somewhere when the building reaches the end of its life. Good design considers every chapter of that story.

A flower is made entirely from materials that belong in nature. Its petals nourish insects. Its leaves enrich the soil when they fall. Nothing it creates poisons the land around it. Every part contributes to the larger web of life. To design buildings that behave more like flowers, the materials from which they are built should also support life rather than threaten it.

The Red List is more than a catalogue of chemicals. It is a reminder that buildings are not simply structures of steel, concrete, glass and wood. They are places where children grow, families gather, patients heal, students learn, and communities flourish.

The buildings we create today will shape the health and well-being of generations to come. Choosing safer materials is not simply a matter of better construction. It is an act of care—for ourselves, for our neighbors, and for the planet we all share.