Halsch launched Overcon Containers to buy and sell used containers in 2015. Two years later, he started ROXBOX Containers to modify containers starting with a mobile taproom called the BeerCan. It quickly took off, and Halsch shuttered Overcon to focus on manufacturing with ROXBOX.

Subsequent to the pivot to manufacturing, ROXBOX quickly expanded from food-and-beverage-oriented modifications to offices -- like the Eldorado Climbing Walls headquarters in Louisville -- and other applications. Pricing starts around $50,000, and goes up from there.

While many manufacturers struggled after the arrival of COVID-19, ROXBOX saw its sales boom. "We basically saw our business go to another level during [the pandemic] era," says Halsch. "We've really gotten good at modular construction, and then the permitting associated with modular. It's not easy, and most clients don't understand all of the process around modular and try to liken it to traditional construction."

As volume increases, so has the breadth of work. ROXBOX has made portable ICU-level hospital rooms and on-mountain restaurants for Winter Park Resort. In 2021, the company launched the HELIOS line of solar refrigerator, freezers, and generators. ROXBOX also went into the residential market with a standardized accessory dwelling unit (ADU) and custom projects in 2021.

The focus is on larger projects, says Halsch. "Most of the stuff we're doing now is larger, permanent builds. It's multiple containers at a time where we're building out some sort of park or amenity."

"We're working with developers and restaurant owners who have multiple restaurants. They know they need this solution and they can get it built 30 to 50 percent faster by using modular construction versus traditional. That's really our biggest advantage, it's speed, and I think a lot of people are starting to recognize that in the development world and the construction world."

ROXBOX's largest project? "We're about to unveil a project we just got done with in Washington state. It was a 25-container dispensary."

Only a few companies can take on that scale of container project. "There aren't a whole lot of us in the country that are doing it at the level that we're doing, and we have a fantastic marketing department," says Halsch.

That's nicely matched by ROXBOX's ever-growing geographic footprint, he adds. "I believe we're licensed in 15 states now as a registered or a certified modular manufacturer, which essentially allows us to manufacture at our factory and then deliver to those states where the foundation's already been built and approved by the local jurisdiction."

While most competitors outsource manufacturing, ROXBOX has handled it in-house since day one. Working primarily with one-trip containers from China, the company works with outside architects and engineers as well as electricians and other subcontractors, but handles most fabrication, welding, and finish work itself.

After almost two years at a 32,000-square-foot factory in northeast Denver, ROXBOX moved manufacturing to Houston in 2023. "We've got a little over 40,000 square feet on 3.5 acres," says Halsch. "The building that we're in is not a building you can find in Denver. It's almost 50 feet tall, it's got two 25-ton overhead bridge cranes so that we can basically fly containers over each other so that we don't have to move containers to move other ones."

In Denver, ROXBOX could accommodate "maybe 12" containers in its facility, he adds. The Houston facility can fit about 40. "That was the biggest issue with our facility in Denver: low ceilings -- comparatively low at 20 feet tall -- but we couldn't have any cranes in there. We had to roll the containers around on caster wheels and things like that. That's not even a consideration here. We've got a big drive-through lane in the front of the building where the semis can drive through, we pick up the boxes with the crane, and we put them where we need to."

Proximity to Port Houston was another factor for the manufacturing move. "The container prices are anywhere from 50 to 60 percent cheaper down here, then the availability of the specialties that we utilize for some of our builds are readily available," says Halsch. "There's just a significant amount of manufacturing down here, so all the supplies are very readily available. There's a lot of welding and fabrication in Houston."

Same goes for labor: "There's a lot of people willing to work. That was one of the difficulties we were having in Colorado: finding people to come to work and do the level of quality that we require at ROXBOX."

Not that the company is abandoning the Centennial State. "We still have our headquarters and our office with sales, design, project management, estimation, and procurement in Denver," says Halsch. "A little more than half of our team is still in Denver, and we're building out our production team in Houston right now. We continue to grow this business down in Texas."

"Honestly, having the leverage of a Denver location and a Houston location, to be able to hire and do remote work, it just allows for a lot more growth from our end, and that's what's exciting for me."

After two years of 500-plus percent growth, Halsch says, "We'll probably double this year. I don't know exactly where we'll get to, but over $10 million for sure."

Challenges: "The next big challenge for us is to get the most out of the footprint that we're in," says Halsch. "When we were in Denver, we thought we had the factory and we thought we could push out as much as we could get sold in a year. That really just wasn't the case. After we started to get those higher-revenue numbers, the shop was jam-packed. I saw we could potentially get to $12 million or $13 million in revenue in Denver . . . but we could probably get close to $40 million out of this building that we're in now."

Opportunities: A more standardized product line that's easier to manufacture in higher volumes. "The next step is 'get big'," says Halsch. "We'll turn from more of a custom job shop where four or five containers are the same to where 50 or 70 or 100 containers are the same, and we just churn them out as a repetitive factory."

He continues, "Food and beverage has been a big driver of everything we do at ROXBOX, and I still see that as honestly getting deeper and deeper. We're getting more into volumetric modular where we're stacking up 10, 15, 20 containers into a single building."

Needs: About 30 more employees. Halsch wants to expand from a single production shift on weekdays to three shifts on both weekdays and weekends. "That's really the next step for us: Now that we have this facility, it's continuing to leverage the space that we have," he says.

Halsch says ROXBOX also needs development partners, noting, "That is really the biggest type of clientele right now that we're going after."