Opening the 1,000th restaurant location is a milestone fewer than 40 limited-service restaurant brands have achieved, and Firehouse Subs CEO Don Fox is well aware that with the new Rowland Heights, California, location—Firehouse’s 1,000th—his company has joined an elite club.

But Fox also isn’t surprised; expansion has always been the only way forward.

“Growth is key for the people in your concept, and your success first and foremost depends on your people,” Fox says. “So growth is very, very important for the vitality of the organization itself.”

Firehouse Subs expects to finish the year with about 1,050 restaurants as it continues to expand across the U.S. and Puerto Rico and into Canada, Mexico, and the Bahamas. It’s also beginning a foray into nontraditional sites like military bases, college campuses, and airports, including its hometown Jacksonville International Airport in Florida.

Brand awareness, distribution, and supply chain were just some of the obstacles the fast-casual restaurant had to overcome while expanding across the U.S. and internationally.

But throughout this whole process, Fox kept one thing in mind.

“As CEO, my most important mission is to protect the underlying culture of the brand,” he says. “Make sure everyone you bring on board embraces it and lives it.”

Fox’s philosophy is simple. The core values and beliefs a company defines will feed a strong culture, and with a strong culture comes great success. With success comes growth, which then gives employees more opportunities to grow within the company. This cycle of success is exactly what has propelled Firehouse Subs forward from its launch in 1994 until today.

“So many things can go wrong from one to 1,000,” Fox says. “If all it took was money just to build out a brand, I could have 3,000 restaurants right now. But it’s about the people that have to be engaged with your brand and operate it.”

Fox cites Firehouse Subs’ diligent franchisee screening process as its biggest differentiator in the industry. No franchisee is hired without interviewing with Fox, the founders, and the CFO. From there, the candidate must spend at least one week with an area representative in an effort to better understand if the opportunity is a career fit. The area representative then has the final approval on whether a perfect match has been made.

This is the exact discipline that many brands are lacking, and it can be their undoing, Fox says. In addition, many companies begin selling franchises too early, which Fox strongly advises against. While debt is a growing pain every business must face, brands should avoid putting themselves in a financial position that results in making “deals out of desperation.”

Firehouse Subs hasn’t had to take on any unqualified franchise partners or purchase subpar real estate opportunities due to financial strain. The company has been debt free for many years thanks to its founders’ frugal practices. The first restaurant opened in Jacksonville, Florida, in 1994 by brothers and former firefighters Chris and Robin Sorensen. But it wasn’t until 2001—seven years later—that the brothers began franchising.

“When you don’t have to make decisions based on financial needs, you can make decisions based on merit and the long-term proposition,” Fox says. “You’ve got to keep your brand in a position of strength.”

When new quick-service restaurant concepts focus internally for a few years, they’ll gain a better understanding of both the brand and the franchise opportunity they’re selling, Fox adds. For Firehouse Subs, a big part of the brand is the Firehouse Subs Public Safety Foundation, which provides funding to organizations like local firehouses for things such as equipment, education, and disaster relief support. In honor of the 1,000th restaurant, the founders donated $1 million to support the 1,000 Automated External Defibrillator (AED) Gift Campaign.

“Every restaurant we open is a chance to touch another community and establish another relationship with another police and fire department,” Fox adds. “Every time we open a new restaurant, it gives us an opportunity to save more lives.”

As the brand has grown, so has the nonprofit foundation. Over $20 million in lifesaving equipment has been donated to public safety entities by Firehouse Subs. And it doesn’t stop there. Fox says the company is well on its way toward its ultimate goal of developing 2,500 restaurants across the U.S.

“We have even bigger and better days ahead,” he says.