Zillow's CEO is warning that the future of work could create a 'two-class system' where those who come into the office are viewed as better employees

• Zillow CEO Rich Barton discussed the future of work during the company's Q4 earnings call.
• A hybrid model could create a "two-class system" that negatively impacts remote workers, he said.
• Others have echoed his concerns. GitLab's CEO called a hybrid model "the worst of both worlds."

Throughout the pandemic, the buzzy phrase in corporate America has been "hybrid model" - as in, a new way of working that involves both remote work and coming into a physical office a few days per week or month.

And while that model seems like an elegant solution for life post-coronavirus, there may be a hidden downside for employees, Zillow CEO Rich Barton warned.

During the online real estate company's fourth-quarter earnings call on Wednesday, Barton discussed how Zillow managed the shift to remote work throughout 2020 and what he's expecting for the future. While Zillow has been successful operating as a "cloud-headquartered company,"the company does plan to have some employees return to its offices, and that can present challenges, Barton said.

"We must ensure a level playing field for all team members, regardless of their physical location," Barton said. "There cannot be a two-class system - those in the room being first-class and those on the phone being second-class."

What Barton is alluding to is that idea that employees who choose to report to the office either some of the time or full-time could be viewed as more dedicated and more engaged than those who choose remote work. Over time, managers may begin to view the employees they can see working in person as more productive than those who they only see over video chat.

Other chief executives agree. Sid Sijbrandij, CEO of code-collaboration firm GitLab, described a hybrid model as "the worst of both worlds" in a piece for Wired last summer. Sijbrandij warned that remote employees won't feel included and will have a more challenging time communicating than their peers who report to the office.

Over time, employees at companies who choose the hybrid model will feel a shift from "remote-first" to "remote-allowed," he said, which creates a world where "remote employees are not penalized for working outside the office, but are also not proactively integrated into the fabric of the company."

Sijbrandij described the old, pre-COVID model of working as being one that rewards attendance rather than output and that many companies will be unable to let that go.

His solution? An entirely remote workforce. GitLab, a $2.75 billion startup, has been remote-only since it launched in 2011. It currently has about 1,280 employees in 66 countries around the world.

Read more: How to get a job at $2.75 billion code-collaboration startup GitLab, despite a nontraditional hiring process where it doesn't accept applications for specific roles

An evolution of the office

Zillow isn't the only tech-driven company considering a hybrid model of work. Google CEO Sundar Pichai has said he expects Google to adopt a hybrid approach, but was clear that the future definitely includes some in-office work.

"We firmly believe that in-person, being together, having that sense of community, is super important for whenever you have to solve hard problems, you have to create something new," he said during a video interview for Time 100 in September. "So we don't see that changing, so we don't think the future is just 100% remote or something."

Read more: Google is 'reimagining' work for the post-pandemic era, but losing its famously lavish office perks could pose a big challenge to its culture

Amazon Web Services CEO Andy Jassy, who will take over as Amazon's chief executive in the third quarter of this year, told CNBC in December that he predicts most people will adopt a hybrid work model and that he expects the future of work to be "hot offices."

"My suspicion is that a lot of these office buildings will start to evolve from being optimized for individual offices or cube space to being hot offices where you decide which day you're going to come in and then you reserve a desk," Jassy said

Travel giant Trivago and cloud computing firm VMware have also said they're adopting a hybrid model of working going forward.

Freeing us from the old rhythms

For Zillow, moving to any kind of remote work wasn't initially a natural transition.

The company has historically been anti-remote work. Zillow's Chief People Office, Dan Spaulding, told CNN's Kathryn Vasel last August that prior to the pandemic, the company viewed its growth and company culture as being defined by collaborating in-person.

"I think there was a belief, that wasn't just isolated to us, that if people weren't in the office that they were doing something else, and maybe that something else was not being focused on their role," he said.

The pandemic, he said, has been able to "free us from some of those old rhythms."

Zillow announced last July that it would allow roughly 90% of its workforce the option to work from home at least part-time on an ongoing basis. Spaulding told CNN that the company expects some people will come in a few days each month, while others will come in three or four days per week.

Zillow recognizes that "there is a balance between where people can be most effective and that balance is unique for all of us," he said. Going forward, Zillow will rely on its physical offices as a space for employees to come work who may not be able to get much done at home, as well as a collaboration space for teams.