For the first time since the COVID-19 pandemic universalized remote work, more than half of Fortune 100 employees in traditionally office-bound, desk jobs are fully back in the office, according to a Jones Lang LaSalle Inc. (JLL) report.

Office attendance in April and May was up 1.3% when compared to the same period last year. Further, the most desirable buildings are reaching record prices. “Trophy buildings across Miami, New York City, San Francisco, and other markets captured all-time high rents,” JLL noted. According to Bloomberg, new construction is asking US$92.38 per square foot—the highest on record.

Hybrid schedules, which two years ago were offered to 78% of desk workers at the 100 largest U.S. companies by revenue, are now available to just 41% of them. Moreover, Fortune 100 employees required to have full-time office attendance has jumped to 54% from 5%.

At the same time, with vacancies hovering above 22%, developers are pulling older buildings off the market. JLL reported national office inventory declined by 700,000 square feet last quarter, as demolitions and conversions—mainly to residential, industrial, or mixed-use developments—outpaced new construction.

The return of employees helps justify costly office leases in premium buildings. Among the 10 largest Fortune 100 employers, JLL found that seven now require at least four days a week in-person, while the other three demand full-time attendance. According to the report, the average in-office requirement of the Fortune 100 rose to 3.8 days per week in the second quarter of 2025, up from 2.6 days in the second quarter of 2023.

Office mandates haven’t been without their ups and downs for big employers, several of which had to regroup after running out of space for all of their returning workers.

The Advanced Research Projects Agency for Health (ARPA-H), an agency within the U.S. Department of Health and Human Services (HHS), named the research and development teams receiving awards from the Building Resilient Environments for Air and Total Health (BREATHE) program.

BREATHE aims to advance the next generation of smart and healthy buildings by developing integrated systems that provide continuous measurement and risk assessment of indoor air quality (IAQ) and deploy real-time interventions, such as enhanced ventilation or disinfection, to mitigate airborne threats to human health.

Poor IAQ exacerbates chronic diseases, such as asthma and allergies, and is a leading cause of preventable respiratory illnesses, including the flu. Rather than only treating illness after it occurs, BREATHE aims to create healthier indoor environments that prevent disease, improve productivity, and enhance quality of life for everyone.

“BREATHE will revolutionize public health by greatly advancing our ability to detect and address indoor air quality threats like never before,” said Jason Roos, Ph.D., ARPA-H acting director. “ARPA-H’s investment has the potential to bring about the next generation of smart buildings, making sure indoor air is always clean and healthy.”

The agency’s initial total commitment to these teams is up to US$156 million during the next five years.  Other Transactions Agreements (not procurement contracts, grants, or cooperative agreements) vary in funding amount per awardee and are contingent upon each team meeting aggressive and accelerated milestones.

“Today, most buildings can’t see what’s in their air, allowing harmful allergens and pathogens to circulate unnoticed,” said BREATHE Program Manager Jessica Green, Ph.D. “BREATHE innovators are closing the gap, so buildings actively protect occupants instead of amplifying risk.”

BREATHE’s teams are led by:

• Mayo Clinic, Rochester, Minnesota, which is developing a biosensor based on microfluidic droplet CRISPR technology. The team will apply cutting-edge technologies, such as agent-based models and digital twin models, to assess the risk of people contracting illnesses indoors. The team will demonstrate its technology in emergency departments at the Mayo Clinic in Minnesota, Arizona, and Florida.
• Poppy Health Inc., Winter Park, Florida, which is developing an amplification-free genetic sensor that sends a tiny electrical signal when it detects a target microbe in the air, allowing buildings to respond accordingly.  The team will demonstrate their technology in 60 U.S. schools to protect children and staff from getting sick indoors.
• SafeTraces Inc., Pleasanton, California, which is developing a novel microarray qPCR biosensor that utilizes a unique positional printing method to detect a broad spectrum of microbes. The team will develop software that triggers a new operating mode for buildings when risk levels are high, including deploying their technology in Defense Health Administration Medical Centers to protect vulnerable patients from airborne illnesses.
• Virginia Tech, Blacksburg, Virginia, which is developing a new biosensor that enables real-time, ultrasensitive detection of specific pathogens and allergens using nanobody-based technology. The project will also deliver software that translates data from the biosensor, building, community, and environment into respiratory risk, as well as tools to optimize proven interventions that reduce bioaerosol concentrations and maintain healthy conditions. The team will demonstrate their technology across multiple daycare centers.

For more information on BREATHE, visit the program page.