Cigarettes built Winston-Salem, North Carolina, just as much as bricks and mortar. By 1916, four decades after an entrepreneurial 20-something named R. J. Reynolds established a tobacco venture there, his company imported so much Turkish tobacco and French rolling papers for its blended varieties that the city became the eighth-largest port of entry in the United Sates—despite being 200 miles inland.

The metropolis is still known as Camel City for its hit brand of smokes, though the cluster of factories that once produced them by the billions is now evolving into spaces for biotech startups, research institutions, and creative firms. TPG Architecture recently breathed fresh (and nicotine-free) air into the third floor of one of these 1920s-era buildings for the advertising agency MullenLowe. Rather than conceal what remained of the building’s gritty industrial past, the New York–based architects worked with its brawny, poured-in-place-concrete structure and peeling surfaces to foster a flexible and creative workplace for an office of 185 people—without the feel of the oft-replicated techie playground.

“A lot of the advertising firms I work for want to be the next Google, with different themed spaces and different colors,” says Carly Jacobson, the lead project designer. Jacobson, who also completed MullenLowe’s Boston office in 2009, continues, “This building had an overwhelming number of assets, so our approach was to make it feel as if we didn’t touch anything.”

To accomplish this, the architects inserted a series of three sleek, geometric volumes within the existing structure. This “box within a box” scheme breaks down the L-shaped, 37,500-square-foot floor office by creating spaces for meetings, while still maintaining open, non-hierarchical work areas.

From a glazed atrium, visitors enter a reception area at the crook of the L. It is a cool respite from the Carolina humidity, all exposed concrete and subdued colors. Here, behind the reception desk, Jacobson and her team located the first box, a freestanding T-shaped volume containing a boardroom and three smaller meeting spaces. “They have these intersecting relationships, as if they are puncturing each other,” explains Jacobson, pointing to where an 11-foot, 6-inch-tall drywall volume collides with 10-foot-tall one clad in plywood. The boxes seem to have been slid into the space like ships into a bottle, allowing for just 1 foot of clearance between some of the columns and as little as 2½ feet below the ceiling slab.

Inside the main conference room, inviting finishes provide a counterbalance to the raw industrial surroundings: slate-colored walls are juxtaposed with white acoustical ceiling panels and tawny birch.Neutral-hued modern furnishings echo existing colors in the factory’s walls and columns. Glazed openings in the boxes allow views directly to the factory’s new perimeter windows, while a hefty 10-foot-tall sliding panel opens the boardroom to the reception area for company meetings and celebrations.

The boxes also solve another challenge: how to unify the creative and business sides of the agency. MullenLowe Winston-Salem president Taylor Bryant says ruefully, “Agencies are composed of diverse people—and those people are not necessarily drawn to work together.”

The placement of the independent containers creates natural neighborhoods for different disciplines. Open-plan workspaces with long rows of shared desks for employees on the business side surround another T-shaped set of conference rooms on the south end of the building. (“They sit here because it’s the more private space,” Jacobson explains.) The creative team abuts a smaller volume on the north side. This end of the office includes amenities that the company’s previous space—a converted bank—lacked, including a 30-person screening room with stadium seating, a photo studio, a sound booth, a printing room, and several editing suites. In these dedicated spaces, MullenLowe can seamlessly develop campaigns for clients ranging from Hanes to a local microbrewery.

Both ends of the office are punctuated by social spaces that include a coffee bar and lounge, a daylight-filled corner “town hall,” and a kitchen. The design team also placed high work tables (hemmed by perforated screens that cleverly double as pinup boards) near the windows to facilitate impromptu meetings and to allow staff members to have a change of scene from their desks.

“We felt the old space was sucking the energy out of people, because everyone was in their own little world,” says Bryant of the former office’s cubicle configuration. “Now you see three people have spun their chairs around. They wouldn’t necessarily call it a meeting, but they are sharing ideas.”

By Bryant’s metric, meetings abounded on a recent afternoon this summer: a group gathered in the lounge to play a round of pool, while others chatted over their microwaved lunches. A full-time barista (brought in from Krankies, a neighborhood coffee shop) made caffeinated beverages for a line of employees. Across the office in the printing room, an employee displayed a freshly inked poster for a staff Tiki party.

They are blissfully oblivious of the subtle particulars that went into creating their industrial-chic habitat. Jacobson and her team, for instance, carefully oriented ductwork over the conference room boxes and rows of desks to emphasize both the volume of the architectural insertions, and to create strong perspectival lines across the work floor. As a finishing touch, the painted concrete columns were lightly sandblasted and sealed to reveal nearly a century’s worth of chipped layers; the effect is something like an abstract expressionist painting. Even with the new additions and new program, the soul of the original Camel City factory still burns bright.