Indoor Air Quality: The Key to Healthier Buildings

I’ve started touring colleges with my daughters and peeking into the dorms. Other families are asking about the meal plan, the roommate matching, and the library hours. Nobody asks what is in the air of the room where their kid will sleep for the next nine months.

I had not thought to ask either, until this June, when I moderated a panel on healthy buildings at Aspen Ideas Health and closed by asking which type of building this country should redesign next with health as the priority. Diana Araoz-Fraser, who has spent 20 years designing hospitals for HKS Architects, did not hesitate: college dorms. Her own daughter came home from freshman year with a cough she could not shake. Diana, who designs healthy buildings for a living, knew exactly what was happening.

This post is about the growing number of conversations I’m having in the private marketplace with developers, building owners, commercial tenants, and employers. It is also for the investors behind them. If you put money into buildings, or into technologies that clean the air inside them, and you want to know whether the numbers actually work, I wrote this for you. That question is what cost-effectiveness models are built to answer, and it is the math I do for a living.

Most American buildings are designed to control odor but not to protect health. Building codes set a very low bar. They tell you the least you can legally do. The misunderstanding i observe is about what the return on investment can be for going well beyond it. I have argued for years that clean indoor air is a classic market failure because it’s a good that benefits everyone and that almost no one has an incentive to pay for. This year, for the first time, I am watching serious money move against that failure, and I want to walk through what I am seeing.

A $500 million investment in the air

The most fascinating development in this space right now is Intercept, a $500 million philanthropic fund launched in June 2026 with a goal that sounds crazy. They aim to radically reduce the burden of respiratory infections, and eventually eliminate them. The premise is simple. Respiratory viruses kill about a million people a year and cost roughly $600 billion annually, and even healthy people lose 15 to 25 days a year, around 5 percent of their lives, to being sick or caring for someone who is.

What Intercept is funding

The Intercept fund is going to deploy $500 million in grants and investments across two complementary tracks. The first is broad-spectrum preventatives: shots, sprays, or pills designed to block many respiratory viruses at once, with a goal of advancing at least two products through Phase 2 trials and a target of preventing 75 percent of symptomatic infections. The second is the one that belongs in this post: air cleaning technologies. Filtration, far-UVC light, and antimicrobial vapors, engineered to cut infectious aerosols in indoor spaces by more than 75 percent, at a cost low enough to reach more than half of the transmission-relevant rooms where we actually live and work.

The theory of change is textbook catalytic capital to de-risk the technologies far enough that commercial markets take them the rest of the way, and line up a customer advisory board and regulatory pathway in parallel. It is the same logic that built clean water infrastructure, applied to air.

Why would Stripe, Anthropic, and OpenAI pay for this?

Now, the part I keep turning over. The backers are Stripe, Anthropic, the OpenAI Foundation, Flu Lab, Bill Gates, and a group of traders from Jane Street, with the effort led by Stripe’s Nan Ransohoff. I have spent years arguing that under-investment in clean indoor air is a market failure, and philanthropy stepping in where markets fail is exactly what the textbook prescribes. Still, I will be honest: I do not fully understand why these particular companies want to make an investment this large, right now.

Maybe it is exactly what it looks like, a group of institutions with money and ambition picking a tractable global problem. Maybe they ran the same math I run and concluded that a world with fewer sick days is worth half a billion dollars to the broader economy they operate in. Or maybe there is a strategic angle I am not seeing yet. I am thrilled they are doing it, I hope it pays off, and I am watching closely for what I might be missing. If you understand the play better than I do, I would genuinely love to talk.

We spend 90 percent of our time indoors. Nine out of ten breaths you take are indoor air.

Joe Allen

Research on the returns

If Intercept is the new capital, the evidence base is already here. A good summary of research is found in the International Well Building Institute (IWBI) special report, Investing in Health Pays Back.

The returns, by stakeholder

The findings that matter most for a private-market audience, pulled from the report’s executive snapshot:

• For employers: a high-performance healthy building yields a net present value of $21,172 per employee, or $115 per square foot over 10 years, counting only productivity, retention, and well-being. Higher ventilation rates alone increase productivity by $6,500 to $7,500 per person per year, and enhanced indoor environmental quality improves cognitive function by 61 to 101 percent.
• For owners and developers: certified healthy buildings rent for 4.4 to 7.7 percent more than comparable non-certified buildings nearby, and the premium holds at 4 to 6 percent even after controlling for green certifications, building characteristics, and submarkets. Spaces with health-focused attributes also sign leases more than a year longer.
• For tenants weighing the upgrade: every dollar spent on workplace wellness saves $3.27 in medical costs, and each additional liter per second of ventilation per person cuts illness-based absenteeism by 1 to 1.5 percent.
• For the economy: the report cites estimates that investing in employee health could create nearly $12 trillion in global economic value, and that raising minimum ventilation in U.S. offices from 8 to 15 liters per second would generate $38 billion in annual economic benefits.

File it under talent, not facilities

The biggest returns usually come from the increased productivity of people. A typical company spends about 90 percent of its costs on its workforce and roughly 1 percent on energy and facilities, and the healthy buildings case goes after the 90, not the 1. That is why I think the private market has this investment miscategorized. It gets filed under facilities, where the returns look small, when it belongs under talent and productivity, where the returns are an order of magnitude larger.

More of us should be building the models

Here is what concerns me as a health economist: the field is still running on averages. A productivity gain from one study, a rent premium from another, a 10 percent estimate across companies in general. Averages start conversations. They do not close deals on specific buildings.

What a defensible model includes

What owners and investors need next is asset-level math with economic models that take one specific building and produce a defensible return on investment for it. A good model resolves the productivity gains, the absenteeism and healthcare savings, the retention effects, and the real estate value into a single net monetary benefit for the asset. Critically, it reports that benefit separately for the building owner and for the business occupying the building, then combines them, because the split incentive is exactly where these investments stall. The owner pays for the ventilation upgrade while the tenant captures the productivity gain, and until each party sees the value in their own terms, both hesitate.

From published averages to your own building’s data

The models should not stop at the literature, either. The next step is the field: swap the published placeholder inputs for a building’s own measured air quality and occupant data, so a chief financial officer can see the return on their own portfolio instead of an average from someone else’s. Investors, building owners, and occupants each deserve an answer to the same three questions: who benefits, by how much, and what does it cost them. That is a math modeling problem, and it is a solvable one.

A panel that brings it all together

The dorm story at the top came from Healthy Buildings for Healthy Lives at Aspen Ideas Health. Dr. Céline Gounder was scheduled to moderate but was called away by a family emergency and she asked me to fill her shoes. That put me on stage with three people who work on this problem at three different altitudes: Joe Allen brings the academic science, Diana Araoz-Fraser brings the architectural design, and Rachel Hodgdon, president and CEO of IWBI, brings the market with a WELL standard that now covers more than 6.5 billion square feet across 130 countries.

The sick building is the default

Joe gave an example of how a sick building lets one infected person spread a respiratory virus to most of a room, contrasting with a healthy building that cuts that risk by 70 percent or more with better ventilation. A sick building uses a filter that catches 20 percent of airborne particles while a healthy building catches 80 percent. A sick building lets carbon dioxide drift past 1,000 parts per million, where decision-making measurably degrades; a healthy building holds it under 800. In every single pair, the sick building is the default.

When Joe presented his cognitive function findings to executives at JPMorgan Chase while advising on their new headquarters, one of them told him that even if the math were wrong by two orders of magnitude, the investment would still be worth it. Joe replied “you’re right, and also the math isn’t wrong.” That building now brings in twice as much fresh outdoor air as code requires, triple filtered, monitored in real time, and it does so as an all-electric skyscraper on renewable energy, which should retire the myth that health and energy efficiency are at odds. Honeywell has found the opposite: a 15 percent additional efficiency gain when you optimize for both. Rachel shared the demand side, where the head of facilities at Citibank calls their WELL Platinum headquarters one giant recruitment engine.

Can an AI data center be a healthy building?

The audience question that has stayed with me asked, “can an AI data center be built as a healthy building?” Joe’s team at Harvard has modeled every data center in Virginia, including the roughly 200 proposed ones, translating energy demand into power plant emissions and then into asthma attacks, missed school days, and premature deaths in the surrounding community. Modest design changes cut that energy demand by about 7 percent, with a measurable health benefit for the neighbors.

Rachel’s answer was sharper and more honest: data centers won’t be healthy until they have to be. Given who is funding Intercept, I suspect the tech industry has been thinking about its relationship to the built environment more than the rest of us realized. That conversation should continue, and I intend to be part of it.

Studio 54 Renovation in NYC

In my consulting work with building owners and employers, my team at Infectious Economics developed math models to estimate the costs and benefits of investment in prevention in the spread of respiratory diseases. We designed and optimized interventions to improve air quality for manufacturing facilities, arenas, retail stores, restaurants, corporate offices, and my favorite, Broadway theaters.

Ten years of theater air

Roundabout Theatre Company was a client I enjoyed working with for years, and their house on West 54th Street is a building whose air I know intimately. Studio 54 has lived four lives. It opened in 1927 as an opera house, became a CBS television studio, spent its wildest years as the world’s most famous nightclub, and has been a Broadway theater since Roundabout restored it in 1998. Each life left its mark on the bones. Many of the dressing rooms sit below the ground floor, with no windows and very little ventilation.

When I was helping reopen Broadway safely in 2021, we set up extra HEPA filters and fans in different places around the theater to keep air moving and purified whenever there were threats of an outbreak. It worked, but it was a patch on a building that was never designed to breathe.

The historic building loophole

The structural problem is that Broadway’s theaters are historic landmarks, and historic buildings operate under different codes. The ventilation floor that is already too low for a modern office is grandfathered lower still for a building from the 1920s, and it shows. I will not name names, but more than one Broadway house has battled mold growing inside those windowless dressing rooms, a genuinely toxic threat to the casts and crews who spend eight shows a week breathing that air. These are workplaces. The people who fill them deserve the same air as anyone in a new office tower, and no landmark plaque changes that.

The producer’s math here is not subtle. A typical Broadway show brings in around $100,000 in ticket sales per performance. If mold makes enough of the cast sick and the understudies run out, the show is canceled and that revenue is gone for good. Preventing mold-related illness backstage is not housekeeping. It lowers the odds of a canceled performance and protects the production’s revenue, and it is exactly the kind of return a cost-effectiveness model can put a number on.

A $100 million second chance

That is why the news out of West 54th Street makes me so happy. Roundabout has launched a $120 million campaign, with roughly $100 million to remodel Studio 54 into a first-class theater. This is the first comprehensive renovation in the building’s nearly hundred-year history, led by David Rockwell and Ennead Architects. The plans restore the orchestra pit that has been buried since the television-studio conversion, rebuild the stage and sloped seating for a house of about 990, and finally address the backstage spaces where people actually work.

The approved renderings are gorgeous. A renovation like this is exactly the moment to design the air in, not bolt it on after, and I hope every historic theater is watching. Most of the buildings we will occupy in 2050 already exist today. The retrofit is where the healthy buildings movement will be won, and I would love nothing more than to see the dressing rooms of Studio 54 become the healthiest on Broadway.

Clean water took a century. Clean indoor air should not.

We figured out clean water infrastructure more than a hundred years ago. We built the treatment plants, wrote the standards, and stopped debating whether safe water was worth it. Indoor air is on the same path, but the sequence is running in reverse: this time the philanthropic capital and the private business case are arriving before the codes. If you develop, own, lease, or fill buildings with people, you do not need to wait for regulation to catch up. The science exists. The design playbook exists. The evidence base now runs 250 studies deep. What remains is the math and the will.

If you are a developer, owner, tenant, or employer trying to figure out what going beyond code would actually return for your building, or you’re an investor in technology to clean indoor air, those are the types of return on investment calculations I love to support. Email me at blythe@infectiouseconomics.com and tell me about your building.

Acknowledgements

Thank you to Joe, Diana, and Rachel for a conversation I will be drawing on for years, and to Dr. Céline Gounder for trusting me with her seat and providing the discussion guide. Blythe wrote this post with assistance from Claude Fable 5 and the YouTube transcript from the panel she moderated. Credit to Hugh Kenny for the header aerial photo of a data center in Haymarket, Virginia.