The average person in the US spends roughly 90% of their life indoors, according to Harvard researchers Joseph Allen and John Macomber, authors of Healthy Buildings: How Indoor Spaces Can Make You Sick―or Keep You Well. It’s a statistic that took on new weight over the past few years of Covid, as we collectively reconsidered the mental and physical health implications of our built environment—and one that feels especially salient right now, as more employees are returning to office buildings and employers are rethinking what those buildings look like.

To better understand what workplaces can do to make their physical spaces more conducive to worker health, we reached out to Allen, an associate professor of exposure-assessment science at the Harvard School of Public Health. Here are excerpts from our conversation, lightly edited for space and clarity:

What is a healthy building?

It’s thinking about places that we spend all of our time in—offices, homes, schools—and how they can be designed and operated in such a way that they are optimized for human health and performance. For the past 40 years, we’ve done the opposite. We’ve designed our buildings without a health-first mindset, and that’s the reason we’ve been in what’s known as the ‘sick building’ era for the past 40 years. We’re in buildings that underperform. You walk into them and you don’t feel alert, it’s not comfortable, you can’t think straight. You get a headache and sometimes worse. That’s largely because public health hasn’t had a seat at that table when we think about the design standards around buildings. The idea of the healthy building is, let’s flip that script. Let’s move from the sick building era into the era where buildings are designed for people.

A lot of times we think of health in these different domains: I’m thinking about Covid and that’s infectious disease, or I’m thinking about productivity, or I’m thinking about mental health and wellbeing. It’s all related. Health is not just the absence and disease. It’s about thriving, flourishing. My interest is demonstrating that the building plays a central role in all of that, because we spend so much time in these places and we haven’t leveraged all the great science that’s out there in terms of how to do better with our buildings.

We did a series of studies we call the CogFX effects study that looks at how indoor air quality influences cognitive function, the influence of air quality on decision-making and performance, things like strategic thinking. How do you respond during a crisis? How do you search out and utilize information? What we find is that controlling for all other factors—Did you just have coffee? What’s your baseline cognitive function?—the air quality matters as well. The results are really striking, because when we model this out in terms of the economic impacts, we estimate that the cost to achieve these healthier building ventilation standards is in the order of tens of dollars per person per year. And the benefits are in the order of $6,000 to $7,000 per person per year.

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In your book, you wrote about the building as a human-resources tool. What does that mean in practice?

I’ll say it this way. When I got my appointment at Harvard, one of the things I negotiated on was my office. I know the place where I work is going to influence my health. I have a great office. I’m looking out over a tree line. I selected this. I ‘interviewed’ my building.

People interview their office for all sorts of things: Where am I going to work? Does it look good? Is it interesting? Is it a cubicle? These healthy buildings become a strategy for recruitment and retention. And then when you have the people there, you’re ensuring their performance is optimized. We talk about this in the book, where we look at Glassdoor and people are talking about the building. ‘It’s too hot in here. I can’t concentrate. The air quality’s bad. This feels like being on a virus-infected cruise ship.’ Great talent you’re trying to recruit is going to see that. But if your building’s performing, then you would see the positive attributes. The pandemic has made it so that healthy buildings are table stakes. You do have people asking about it, and if you don’t have an answer, you’re going to get caught.

What does it mean for employees to ‘interview’ their building?

During the interview, people are interested in the values of the organization: ‘What do you do on sustainability? What are you doing for climate? What are you doing for equity, diversity, inclusion?’ You could ask, ‘What do you do on healthy building strategies? Have you enhanced ventilation?’ And without having to be technical, you’ll learn a lot just from that answer. If they stare at you blankly, there’s your answer. A good organization’s going to say, ‘Yeah, we have a great diversity, equity, and inclusion plan. We are committed to green buildings and energy efficiency. Here’s what we do on climate. We’ve enhanced all the ventilation. We have great filtration. We have green cleaning products. We’re really integrated in this healthy buildings, green buildings space.’ You don’t need to know anything more than that to know that the organization has prioritized your health in the right way. You don’t have to ask, ‘Are you hitting 30 cfm per person?’ or ‘What grade filter do you have?’ Just ask the question and see the answer you get back.

What should workplaces be doing and thinking about at this point regarding Covid, especially as a lot of organizations are rethinking their office designs?

First and foremost, you have to recognize how this virus and other respiratory viruses spread. They’re spread through the air. Respiratory air cells travel beyond six feet. That means the building matters. So if you start from that, how it’s spread, then the rest flows naturally. If you want to prevent the buildup of respiratory particles, you have to pull it out of the building with good ventilation or clean it out of the air with filtration. So organizations should be thinking about beyond the current minimums, because the current minimums of ventilation filtration are not designed for health.

The standard for ventilation right now is called the standard for acceptable indoor air quality. The problem with the name ‘acceptable’ is, it’s a minimum. The typical filter that’s used is designed to protect equipment, not people. We need filters that are designed to protect people. We need ventilation standards that are designed for the health of people, and that hasn’t been the case. This isn’t hard, it’s not expensive. It’s not the case that only shiny new buildings can do this work. Any building can be a healthy building. So I’d focus right there, because the strategies are going to be good for influenza, coronavirus, whatever hits us next, RSV. It’s going to be good for managing outdoor air pollution. It’s good for filtration against pollen and other allergens, protection against wildfire smoke. So you shouldn’t think of these strategies as Covid strategies. They’re just general public-health strategies that keep your employees healthy, keep them from getting sick, and also help them perform their best in your space.

When you take the CogFX study—which we’ve done in a lab, we’ve done in buildings across the US, and we’ve done replicated in buildings around the world with the same results—you see that indoor air quality becomes a worker productivity issue. Think about the business case for healthy buildings. On an individual level, breathing better air is better for cognitive function and performance, and in our book, we roll that up into what that means for business. What we find is if you make these improvements, it leads to reductions in absenteeism, better cognitive function, and leads to 10% gains to the bottom line. Our colleagues down the road at MIT did a study showing that healthy buildings commanded higher rents per square foot. You could take that to another level. There have been studies looking at the macroeconomic benefits: over $20 billion in benefits to the US economy with improvements to indoor air quality. So whether you look at an individual level, a business level, an investor level, owner level, a societal level, there’s a business case to be made.

I’m a public-health professor, so I’m interested in people’s health as the ultimate goal, but it’s also just good business.

Read a full transcript of our conversation, including Allen’s thoughts on setting ventilation targets and how the healthy-buildings movement and the green-buildings movement align.

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