1 in 3 workers would rather have a casual dress code than an extra $5,000 in pay

THE OFFICE: "Casual Friday"

What's the value of being able to show up to work in your favorite T-shirt and jeans? For one in three workers, a cool $5,000.

At least, that's what they'd be willing to give up in salary in order to work for a company that has an informal dress code, according to a recent survey from Randstad US, an employment and recruitment agency.

From its sample of over 1,200 employees, the agency found 33% would fully quit their job or turn down an offer if they were required to follow a conservative dress code. The general population survey represented employees across all types of industries, including retail, advertising, banking and finance, government, legal services, transportation and more.

Flexible dress in the workplace has come in fashion over the years, with half of organizations reporting they allow casual attire every day, according to the Society for Human Resource Management's 2018 benefits report. That's a 6% increase from the year prior and 18% from 2014.

While the thought of casual dress policies may conjure up images of tech workers in start-up-branded hoodies, more traditional companies are loosening the ties, too.

In 2017, Goldman Sachs made headlines when it released a memo allowing its tech staffers to wear "totally casual clothing." And as of March of this year, the investment bank announced it would relax the dress code company-wide for 36,000 employees, citing "the changing nature of workplaces generally in favor of a more casual environment."

Outside of Wall Street, a relaxed policy has quickly become something workers expect from their workplace. A combined 79% of workers surveyed by Randstad US reported their current workplace dress code was either business casual, casual or non-existent.

A casual dress code isn't just good for employee satisfaction, says business mogul Richard Branson: It can boost the bottom line.

"If people got rid of unnecessary hierarchies and formalities, they would have a lot more fun and get a lot more done," he wrote on his blog. "At Virgin Management, our receptionist is Rhubi, our CEO is Josh, and I'm Richard. There are no tucked away offices, just shared working spaces. And everyone is encouraged to wear what they think will help them to work most productively — you won't find a tie in sight."

That said, ties do have their place in the professional space: 65% of workers from the Randstad US survey said they felt it was important to wear a suit to an interview, regardless of the company's dress code.

Like this story? Subscribe to CNBC Make It on YouTube!

Don't miss: Anna Wintour says this is the No. 1 mistake you should avoid when dressing for a job interview

4 rules for dressing for interview success
4 rules for dressing for interview success