Once the status symbol of anti-establishment Silicon Valley tech companies such as Google and Facebook, the open office floor plan now pervades American workplaces. According to The Washington Post, about 70% of U.S. offices have an open office floor plan.

Supporters say open floor plans provide opportunities for collaboration, improve transparency, eliminate many emails and phone calls, and encourage employee relationships. Cost savings and attracting millennials are also factors for some companies.

Detractors claim that they increase distractions and decrease productivity. Some CEOs, according to The Wall Street Journal, think the open office trend has gone too far.

So what should be the primary considerations when deciding on an open office floor plan? And if your place of employment already has an open floor plan that isn't working, how can it be fixed?

Based on Gallup's recent State of the American Workplace report, here are three key concepts to keep in mind for any workplace plan:

1. Make room for human nature.

Humans are naturally territorial. From personal bubbles to "my spot" at the cafeteria table, people believe they own space. We all have a need for a space that feels like it's ours, where we have control and autonomy.

Even as trends come and go, Gallup research shows that people still want a personal space at work. According to our recent State of the American Workplace report, employees who have a personal workspace are 1.4 times more likely to be engaged at work.

That said, acceptable boundaries for that workspace are always in flux. Needing personal space doesn't require having an office or a large desk. It can be communal ("my team's area"). It can be explicit ("my name on the door") or implicit ("my chair").

But most importantly, it needs to be settled. As many organizations can attest, nothing quite taps into our primal defensiveness like telling us we need to move our "home" somewhere else. For this reason, buy-in among managers is essential for a successful office transition.

The two key lessons for leaders are these:

• Allow every employee to have a home base, even in a flexible, collaborative office. As referenced above, this can be a locker, a table or even a chair.
• Be prepared for negative reactions when you inform your employees that their home must move. Good communication and clarity can help mitigate these reactions.

2. Create flexibility through cultural norms and physical space.

Culture also plays a role in what are acceptable and unacceptable ways of working. Every office culture has nonverbal signals that say, "Do not disturb!" In a traditional office, it may mean shutting the door. In an open floor plan, it may mean putting on headphones.

In your open office floor plan, do employees have the ability to move to different places to signal that they need to be left alone? Can they make a personal phone call or have a private side conversation with a coworker when necessary? And most importantly, does everyone understand and abide by these unspoken rules?

It is impossible for an employer to satisfy every employee's needs at all times and to predict how the flow of business may change in the future. Different jobs have different work requirements, and those jobs are filled by unique people who have unique talents. If we take that seriously, there can never be a "one size fits all" solution for workspaces.

The important thing is to provide a variety of types of spaces -- big group tables, booths, comfy chairs, soundproof areas, large and small meeting rooms -- that allow employees the freedom to choose how they work best.

According to our research, employees who have the ability to move to different areas at work are 1.3 times more likely to be engaged than other employees.

To establish a flexible culture, concentrate on the following:

• Consider how employees will be able to nonverbally signal, "Do not disturb."
• Give employees a mix of workspaces and the freedom to adapt throughout the workday.
• Offer remote working and flextime options if role requirements allow for them.

3. Redefine productivity.

Here, we get to the heart of the matter: productivity vs. collaboration. Opponents of open workspaces offer up studies showing that these spaces have negative effects on concentration and privacy, thus potentially affecting productivity.

However, open floor plans also create more collaboration. Ideation, brainstorming and "concepting" sessions may lead to new ways of thinking.

Collaboration may look less productive by traditional measures -- which may mean we have to discover new ways of proving the business value of collaborative environments.

Here are a couple of action items to help you begin to redefine productivity:

• Start a conversation about how your organization understands collaboration in relation to productivity.
• Increase coaching conversations with highly matrixed employees to help resolve unclear expectations and confusion about priorities.

Open office floor plans work best when decision-makers take into account the human needs of workers, the nature of the work being done and the culture of the organization itself. When done right, open offices give employees the freedom to decide how they work best and create an environment where organic brainstorming can occur.

Want more insights on today's changing workplace? Download Gallup's 2017 State of the American Workplace report.