Healthy Buildings Should Become the Baseline, Not a Premium Upgrade

Joseph Allen defines a healthy building by first describing its opposite. In his account, the unhealthy version is not an edge case: it is the default operating model for much of the built environment.

A sick building, Allen said, is one where a respiratory virus can move through a room so efficiently that one infected person might infect 80% of the people present. A healthy building uses better ventilation to reduce that risk by 70% or more. A sick building uses a weak filter that captures roughly 20% of airborne particles; a healthy one uses a filter that captures roughly 80%. A sick building traps heat during a heat wave and fails to shed it at night; a healthy one manages thermal conditions through better materials and efficient cooling. A sick building lets carbon dioxide levels rise above 1,000 parts per million; a healthy one keeps them below 800 parts per million, a threshold Allen tied to research on ventilation, indoor air quality, and cognitive performance.

He put chemical exposure in the same frame. “Forever chemicals,” a term Blythe Adamson noted Allen coined, are used in products such as nonstick pans and stain-repellent carpets. Allen said 98% of people have these chemicals in their bodies, and connected them to testicular cancer and weight gain in women. A sick building assumes those chemicals are necessary and uses them broadly. A healthy building chooses better materials and reduces the chemicals in the indoor environment.

The central claim was blunt.

Allen traced that default to a change in ventilation standards. He contrasted Florence Nightingale’s 150-year-old emphasis on “cleanliness and fresh air from open windows” with what happened in the 1970s energy crisis, when buildings were sealed to save energy. In his telling, the air supply was “choked off,” contaminants accumulated indoors, and the “sick building era” began.

Earlier health-based ventilation codes, he said, were cut by half or more. The governing logic shifted from controlling respiratory pathogens and pollutants to controlling odor. The practical standard became whether the next person entering a space would leave because it smelled like body odor. Allen emphasized that this odor-control basis applies broadly: homes, offices, coffee shops, airplanes, and even airplanes.

Adamson framed the stakes at the start: people spend about 90% of their time indoors, in homes, offices, schools, hospitals, and other buildings, and most assume those spaces are at least safe. Allen’s answer was that the assumption is too generous. Buildings are not neutral containers for life; they can increase or reduce infection, air-pollution exposure, heat risk, chemical exposure, and cognitive burden.

The public-health stakes were clearest in schools, dormitories, mental health facilities, homes, and other places where vulnerable people spend long periods and often have little choice.

Rachel Hodgdon connected her career to her mother’s experience working for a local school district for 22 years. Many of the buildings, she said, were sick buildings. In one case, her mother walked into a portable classroom — the district called them “learning cottages” — and suddenly could not breathe. Hodgdon described such classrooms as often lacking active ventilation, using poor-quality off-gassing materials, and containing mold. Her mother told the teacher something was wrong; the teacher, relieved, brought her to the principal because she had already been trying to get attention for weeks. Testing found the classroom was covered in mold. When the school reviewed attendance records for that classroom, Hodgdon said the problem was “through the roof.” The school was then moved up the renovation list.

That experience fed into Hodgdon’s earlier work at the U.S. Green Building Council’s Center for Green Schools. The original mission there was to create buildings better for the planet through LEED. Along the way, she said, the organization saw that many strategies reducing environmental impact also benefited human health. Teachers told her their “2:30 headache” disappeared after moving into LEED schools. Students told her they used to have asthma attacks Monday through Friday until they moved into a new school.

Diana Araoz-Fraser chose mental health facilities when asked which building type she would redesign from the ground up with health as a priority. They still often do not meet a minimum standard of care or spatial quality, she said, even though people may live in them. She called for more investment and research, and said she would like to work on a state-of-the-art facility that could be a candidate for WELL accreditation.

Her personal answer was college dorms. Her daughter had recently graduated from college, and Araoz-Fraser remembered the cough her daughter could not get rid of after her first year. It made her “sick to my stomach,” she said, because she knew what was happening. New showcase dorms exist, but she argued the baseline should rise so that every college dorm is a healthy building for students.

Residential buildings require a different pitch. Allen said he changes the value proposition by sector: for businesses, cognitive performance and productivity; for schools, air quality’s impact on reading and math scores; for homes, rest, recovery, and sleep. A person spends a third of life in “one little box on this planet,” the bedroom, so that air needs to be healthy. The strategies to improve it, he argued, are not especially difficult.

Hodgdon said demand for healthy residential design has surged since the pandemic. IWBI opened a pilot for WELL for residential certification, applicable to multifamily and single-family homes. The organization expected 3,000 residences to enroll; 30,000 enrolled, followed by 15,000 more in another pilot. For Hodgdon, the scale shows that the pandemic made people viscerally aware of how much the home affects health and productivity.

Consumer demand in residential may outpace codes, she said, but the bottleneck is training. Builders and residential architects are often not trained to implement healthy-home strategies. Hodgdon said her own family paid for that learning curve when building a home, and IWBI developed a Healthy Homes course with the American Society of Interior Designers to teach the basics, not merely how to obtain certification. The strategies are often easy to do once professionals know to do them; the missing piece is making them visible.

Adamson put the analogy in infrastructure terms: society figured out clean water infrastructure more than a century ago; the question now is whether it can do the same for indoor air.

The pandemic forced workplaces, schools, theaters, and other public spaces to confront problems that healthcare design had already made routine: infection control, circulation, flexibility, cleanability, and the measurable relationship between space and outcomes.

Diana Araoz-Fraser said hospital design starts with code requirements but does not stop there. Healthcare design also uses evidence-based design, which she described as designing from measurable outcomes. That discipline meant hospitals had a vocabulary and set of practices ready when other sectors suddenly needed to think about infection and flow.

Flexibility is central because hospitals may be built for 70 years while the technology inside them changes. Araoz-Fraser called flexibility and adaptability a form of “future-proofing.” During the pandemic, those design habits could be transferred to workplaces and other environments: assessing projects, changing the flow of people, separating sick or potentially sick entrants from staff, and thinking through what she called “on-stage and off-stage” movement.

Infection control was the recurring design driver. Araoz-Fraser said there is “not one day” in her work when she does not discuss it with clients. The design questions become practical: how fast can a space be cleaned, how well can it be cleaned, and what will be used to clean it? That logic leads to decluttering and simplifying space. The goal is not to make the building feel clinical, but to make the user experience work while removing unnecessary surfaces, obstacles, and operational complications.

A well-planned hospital should have clear wayfinding; patients, families, staff, and visitors should be able to enter and understand where to go. The space should support staff working behind the scenes and still feel calm for patients and families. If it works well, people may not consciously notice why.

Safety broadened the discussion beyond air. Conversations about health and violence happen every day in healthcare design, Araoz-Fraser said, particularly around emergency departments, which she called among the most vulnerable spaces in a hospital. The entrance experience, sightlines, staff protection, and de-escalation all become health issues.

She also emphasized neurodivergence, lighting, privacy, and acoustics. Some users may need brighter light; others need a more private or subdued setting. Acoustics matter because noise can aggravate distress and make de-escalation harder. In behavioral health and emergency settings especially, design choices can either increase or reduce conflict.

The nurse station became her example of subtle design influencing outcomes. Araoz-Fraser said she had researched nurse stations and the tension between decentralized stations closer to patients and the need for core team interaction among physicians, nurse practitioners, nurses, and others. The design should increase time spent with patients and improve the patient experience. Good design, in her account, is not decoration; it is a way to allocate attention, reduce friction, and support clinical work.

The corporate argument for healthy buildings rests on a different denominator. Energy and facilities costs matter, but Rachel Hodgdon argued that the larger business lever is the workforce: recruitment, retention, perceived productivity, health, engagement, and the daily experience of returning to the office.

At Citibank’s WELL Platinum and LEED Platinum headquarters in New York City, Hodgdon said the head of facilities described the building as “one giant recruitment engine.” In a market where competitors can offer similar compensation and benefits, the building becomes a differentiator. She made a similar point about JP Morgan’s new headquarters, noting its air quality and the decision to place health and well-being amenities on one of the top floors with the best views, rather than reserving those views for executive suites.

Hodgdon said many WELL customers see double-digit improvements in retention, health and well-being, and perceived productivity, and described WELL as the most studied building certification through third-party peer-reviewed research. For the largest customers, she said, recruitment and retention are often the biggest drivers of participation.

The Big Four example sharpened the point. A workplace and well-being leader at one of the firms told Hodgdon that retention was one of the organization’s most important metrics, not because it was good, but because the firm cared whether it was better than the other three. If he could improve retention by one percent, he told her, he would be a hero. Hodgdon said organizations implementing the WELL roadmap see improvements greater than that.

Allen supplied the pro forma version. With Harvard Business School professor John Macomber, he said, he estimated bottom-line benefits to companies “on the order of 10%,” based on reduced sickness absence, fewer asthma attacks, fewer doctor visits, and improved cognitive performance. He also described research estimating a $6,000 to $7,000 per person per year benefit from indoor air quality improvements. When he presented that estimate to a JP Morgan executive years earlier, Allen said the executive replied that even if the math were wrong by two orders of magnitude, the investment would still be worth making. Allen said the executive was right — and that the math was not wrong.

Hodgdon framed the economic logic as a shift in what building owners count. The green building movement, she said, often made its financial case around the roughly 1% of annual expenditures spent on facilities, energy, and utilities. But companies spend about 90% of their costs on people. If buildings can affect the health, productivity, and retention of those people, the leverage is much larger.

Healthy buildings also differ from many workplace wellness programs. Programs often require workers to opt in, and the people who opt in may already be among the healthiest in the workforce. Better air quality, acoustics, lighting, and water do not require opt-in. They are passively delivered to everyone who enters.

Physical amenities alone do not work. Hodgdon recalled speaking with Google’s head of mindfulness, who said people congratulated him for getting meditation rooms into offices even though the rooms were often empty. Without supportive employee programs, training, and a culture that allows people to use those spaces, the design does not achieve its intended effect. WELL, she said, deliberately combines physical environment measures with organizational policies, benefits, amenities, and programs.

Joseph Allen called JP Morgan’s new headquarters “the beginning of the end of the sick building era” because it demonstrated, in his view, that a major building could be designed around health-based ventilation and filtration rather than the odor-control baseline.

He said he worked with architect Lord Norman Foster and JP Morgan executives who valued employee health. The building brings in twice as much fresh outdoor air as conventional standards, uses triple filtration with what Allen described as “the world’s best filters,” monitors air quality in real time, and uses healthier materials, good lighting, and good acoustics. The design did not, in his words, “cut corners when it comes to health.”

The significance was partly the resistance. Allen said engineering firms told him a decade earlier that the proposed ventilation rates could not be done. JP Morgan executives insisted they had to be done. Once the client made health non-negotiable, the engineering firms found a way.

Allen later saw some of the same engineering firms selling the service for other buildings. That, for him, is how the market moves: one high-profile project establishes a new standard, firms learn how to deliver it, competitors feel pressure, and the ecosystem begins to change. The aspiration is not only better headquarters for JP Morgan and Citibank, but a pathway toward “healthy buildings for all.”

He also cited feedback from the building itself. The air quality monitoring, he said, objectively shows improvement, and teams report that people like being in the space and feel better there. The prior building was good, he said, but this one is extraordinary.

The larger lesson was about what had been treated as impossible. Public health, Allen said, has not been the North Star for building design and operations. JP Morgan showed that it could be.

Healthy buildings and energy-efficient buildings are often described as if gains for one require losses for the other. Hodgdon, Araoz-Fraser, and Allen each rejected that tradeoff.

Rachel Hodgdon described the conflict as a myth propagated in part by market-transformation leaders who had become “protectors of the status quo.” When she moved from green building to healthy buildings, some warned that focusing on health would undermine progress on efficiency. Her claim was that the evidence and practice point in the opposite direction.

She cited Honeywell studies that she said found a 15% improvement in energy efficiency when human health is factored in. Her practical explanation was occupancy responsiveness: a building does not need to bring large amounts of fresh air into an empty room, nor keep lights on in unused spaces. If buildings respond to the needs of people actually present, she said, they can produce further energy gains.

Hodgdon also described her own multigenerational home with her parents as net positive, producing more energy than it uses while maintaining continuous fresh air, high-grade filtration, and warm-dim lighting designed to support circadian rhythms and sleep. Most WELL-certified spaces, she said, are also certified under some type of green building certification. Healthy buildings, in her formulation, are not a distraction from sustainability but a “second wave” that puts human health at the center.

Diana Araoz-Fraser stressed process. The health-and-energy integration has to begin early, with client buy-in and engineers in the same room. In healthcare, some requirements are non-negotiable: HEPA filtration in certain areas, pandemic preparedness, isolation capacity, and patient control. The issue is not choosing one value over the other, but modeling the design from the beginning around what must work.

Joseph Allen was more forceful. People have been fed a false notion that energy and health are in a tug-of-war, he said. The 1970s solution, as he characterized it, asked people to save energy by accepting sick indoor environments. That was unacceptable. He also said it would be irresponsible to design a healthy building that does not do right by the planet. His point was that the choice itself is often false.

JP Morgan was again his example. Critics warned that doubling the ventilation rate would “kill” the building on energy. Instead, Allen said, it is an all-electric skyscraper in New York, sourced with renewable energy, with no fossil fuels. It uses demand-controlled ventilation: air is delivered where people are present and reduced where they are not. It uses heat exchangers or heat recovery, conserving energy from heated or cooled outgoing air by transferring it to incoming air streams. These strategies, he said, are available and not prohibitively expensive.

Allen described the energy-health false tradeoff as “one of the biggest public health mistakes” of the current generation. He returned to the scale of exposure: nine out of ten breaths are indoors; a person living to 80 spends roughly 72 years inside. Designing those places only to protect against body odor, he said, is “absolutely crazy.”

The question is whether healthy buildings become ordinary or remain a premium feature in new headquarters. Diana Araoz-Fraser identified one false barrier as the belief that healthy buildings are only possible in new construction. Her work, she said, is largely retrofit. The majority of buildings are already here, so the task is to make existing spaces better.

She pointed to The Children’s Inn at NIH, where she serves on the board, as an example. The project involves a renovation and expansion of an older facility that serves children in clinical trials as a “home away from home.” The goal is to elevate the standard for everyone using and working in the building, and the project is pursuing WELL accreditation. For Araoz-Fraser, the example shows that an old facility can be upgraded thoughtfully and correctly.

Adamson added a concrete pandemic-era retrofit problem from her own work reopening Broadway theaters in New York City in 2021. She described entering historic theaters with no ventilation, dressing rooms without windows, mold, and orchestra pits full of brass instruments. It was, she said, terrifying to figure out how to do safely. The anecdote underscored why voluntary best practice may not be enough: many existing buildings were never designed for the health risks they were being asked to manage.

Joseph Allen said the goal cannot be limited to “great new shiny buildings” for elite companies. Health has to be built into standards so that ordinary buildings do not need a special plaque to be healthy. There is already consensus among leading scientists on health-based ventilation and appropriate filtration, he said. The problem is the code machinery moves slowly.

Still, Allen said momentum exists. He cited model codes and standards, legislation emerging in states and cities, and a network of indoor air quality and healthy-building researchers, scientists, and policymakers. Boston Public Schools, he said, now monitors air quality in schools; Rhode Island and other states are starting to follow. Even incremental increases in ventilation rates, in his view, would produce large benefits.

His desired end state was a kind of professional obsolescence: no need for healthy-building experts because health is simply part of the code.

The definition of a healthy building did not stop at ventilation, filtration, or workplace performance. It also included the relationship between buildings and nature, and the effects buildings impose beyond their walls.

Asked whether the healthiest future buildings would be historic classical buildings with biophilic design or glass-and-steel buildings like JP Morgan’s, Joseph Allen rejected the binary. Biophilic design, he explained, is the practice of reconnecting indoor environments with nature, drawing on E.O. Wilson’s biophilia hypothesis: humans are innately connected to nature. It is not limited to plants; it includes biomorphic shapes, patterns, natural light, and other design principles.

A glass-and-steel building can use biophilic design, and JP Morgan’s does, Allen said. Historic buildings can also do it. The relevant issue is intentionality, not architectural style. He described research using virtual reality to test the effects: his team created virtual office spaces, stressed participants with a math test, tracked heart rates, and randomized them into either a typical office space or one designed with biophilic principles. In the biophilic spaces, stress recovery was faster and cognitive test performance improved.

Rachel Hodgdon offered a real-world example from Singapore: Temasek Shophouse, a WELL Platinum social impact hub created from four historic buildings more than 100 years old. The project pursued healthy building design alongside inclusive and equitable design, with attention to air quality, biophilia, community connectivity, outdoor space, an edible garden, and rainwater harvesting cisterns that also provide shade in Singapore’s heat. The project, she said, was not done on an excessive budget. Her conclusion was that some of the healthiest buildings in the world today are historic buildings.

Data centers built for generative AI shifted the health frame from occupants to the surrounding community. Allen described Harvard’s CoBE tool, short for Co-Benefits of the Built Environment, which models how building decisions affect energy use, air-pollutant emissions, and population health. His team modeled data centers in Virginia, including the next 200 proposed. Certain changes to a data center, he said, could save about 7% of its energy use, reduce air-pollutant emissions by the same amount, reduce exposure for the local population, and generate a health benefit.

The point was partly about translation. CO2 averted can be abstract. Translating emissions reductions into health outcomes — missed school days averted, asthma attacks prevented — makes the stakes clearer and connects building decisions to community health beyond the property line.

Hodgdon made the permitting and social-license argument. The question is not whether data centers can be healthy, but whether they will be. More than half, she said, are held up in permitting by communities objecting to their siting. Communities should ask more of data centers: not just regenerative design, but community connectivity, reinvestment, opportunity, and jobs. She worried that current demand creates pressure to “jam as many of them down local throats as possible.” For WELL, she said, the possible role is less about environmental impacts and more about social license to operate. But that raises a risk: helping data centers check boxes to win permits rather than ensuring good-faith community benefit. Her judgment was that they will not be well-intentioned until they have to be.

Arcelia Mendoza asked the final question as a disability advocate and journalist: the Americans with Disabilities Act requires public places to be “somewhat accessible,” but residential homes often are not. Anyone can become disabled, have a child with a disability, or face a diagnosis or injury. Why are most homes not accessible, and what design choices or programs could support independence without forcing families into expensive renovations later?

Joseph Allen answered that the problem reflects piecemeal regulation and sector-by-sector standards. Residential codes differ from office codes, which differ from local retail or coffee shop requirements. He said his students — both public health students and architects or designers — are asked to enter spaces and think deliberately about accessibility, and the exercise opens their eyes to how often spaces are not designed that way. His answer was to fold accessibility into the same broader project of codifying healthy buildings, so lighting, acoustics, ventilation, and accessibility are not treated as disconnected specialties.

Rachel Hodgdon put the critique more sharply: when buildings are designed merely to meet code, they are “one step short of breaking the law.” ADA, she said, set an important minimum bar, but needs to evolve in light of what is now understood about accessible and equitable spaces. WELL spent two years with researchers and practitioners identifying ways to embed more equity, accessibility, and inclusivity into its standard, including residential systems. Many strategies, she said, are affordable.

The broader principle is that designing for people with more extreme or unusual needs tends to benefit everyone. Hodgdon’s example was the curb cut: designed for wheelchair accessibility, but useful to people pushing strollers, children on scooters, and people who are temporarily disabled. The same principle applies to wayfinding, future retrofit capacity in homes, and other design choices.

Diana Araoz-Fraser described this as universal design: designing for every need because no one knows who will need the space at a given time. In hospitals, homes, and other settings, that includes lighting, patient size, disabilities of many kinds, acoustics, comfort, safety, and dignity.