A former HVAC warehouse in Denver finds new life as an event space, coworking spot, and food truck park—all rolled into one.

Improper City interior

[Photo: Courtesy of OZ Architecture]

Like Denver itself, Improper City is a work-hard, play-hard kind of spot—one that includes coworking space but also a 36-tap bar, coffee shop, and food truck patio while also sharing a roof with a climbing gym. Located in River North, aka RiNo—a former industrial hub that has transformed into a thriving arts district, craft brewing mecca, and landing pad for quirky, high-rise–averse companies—the project is classic adaptive reuse, as the former HVAC warehouse transformed to fit the neighborhood’s new reality with some much-needed social space.

“It provides open space and a gathering space,” says Becky Stone, of OZ Architecture, which designed Improper City and its headquarters. “It’s a pretty dense area that has been redeveloping, but there’s not a lot of spaces where people can gather. There weren’t a lot of park spaces where all these [industrial sites] were built. So just to have a place where people can go sit and have a coffee or hear music has been pretty wildly successful.”

Improper City exterior shot

[Photo: Courtesy of OZ Architecture]

Like most post-industrial conversions, the project was rich with as-is character, notably in the well-kept concrete floors, but also required some interventions: The roof had to be redone to meet energy requirements, and structural X-bracing was installed to meet shear and racking requirements. Perhaps the most unusual intervention was zoning-related. Improper City’s interior bar/coworking area is separated from its food truck patio by a public alleyway.

“They essentially had to privatize the alley in order to have a liquor license that would cross that public right of way,” Stone says, adding that it took nearly a year for the city to come around to the idea. But ultimately, when OZ put its plan to the Denver Board of Adjustments, the body approved it unanimously. They also had to work around some outdated zoning regulations related to food trucks.

The project is not drastically dissimilar from the owners’ Rayback Collective, a food truck park-meets-music venue in Boulder. Though with Improper City under the same structure as its bouldering gym neighbor, Movement Climbing + Fitness, the space allows for unique collaboration possibilities. “If you wanted to have an event in the climbing area and be served by Improper, you can make it kind of free-flow,” Stone says. “It’s pretty flexible.”

And the nightly transition from working space to leisure destination goes smoothly, too, especially now that the patio has opened. “We have a lot of people working on their laptops outside on our picnic tables in the afternoon, which just lends to having a beer, which leads to texting your friends,” says Lexie Roberts, Improper City’s event manager. The overall result has been a multi-use success, hosting everything from blockchain promotional events and live music to knitting group meetups and seasonal beer releases.

Improper City lighting design

[Photo: Courtesy of OZ Architecture]

Lighting Design

The site had attractive ceiling trusses intact, but OZ Architecture added skylights since the former warehouse was short on daylight. Much of the lighting design was propelled by the needs of the bouldering gym clientele next door. “It was important at the gym for the light to be diffuse from above and not shining in bright,” Stone says. “We handled the whole building in a similar way, even though it was sort of driven by what the climbers would want in terms of lighting.”

Improper City open plan

[Photo: Courtesy of OZ Architecture]

An Open Plan

While high real estate costs in RiNo would prompt many buyers to maximize their square footage by building up, Improper City ownership wanted to keep things open with a xeriscape-style patio space, where food trucks and visitors could gather. “Most developers would have tried to build five stories and capture every inch they could,” Stone says. “I think that’s the most sustainable thing they did.”

Improper City bar

[Photo: Courtesy of OZ Architecture]

The Bar

A quote above the bar references travel writer Rose Kingsley, who once wrote of a then-nascent Denver, “It was as if the angels were carrying a city to a proper place and accidentally dropped it here.” (Improper City derived its name from the quote also.) Also on display is the project’s unique approach to wood cladding and use of subway-style tiles for the bar wall finish—key design features from the outset.

Improper City stadium seating

[Photo: Courtesy of OZ Architecture]

Stadium-style Seating

This seating is slightly recessed from the open space, providing an optimal spot for the coworking crowd to work privately or hold small meetings. (There’s no fee to use the space for remote working.) Beyond the bar is a mezzanine, which helps separate uses if needed. On a recent May weekend, for instance, Improper City held a silent auction upstairs and a silent disco downstairs, Roberts says. “I also hosted my son’s first birthday party in the mezzanine with about 30 friends and their kids, so it can be very versatile,” adds co-owner Hank Grant.

Reflected ceiling plan

[Drawing: Courtesy of OZ Architecture]


Learn more about Improper City and see more gb&d commercial architecture stories.