The marketing materials for SoNo, a new "creative office space" being developed at Fifth and Spring Garden, depict a millennial's workday paradise. Softly colored renderings show handsome folks grabbing lunch from food trucks, dropping off bikes at a sleek storage room, and lounging around the amphitheater in a dramatic skylighted lobby. In the evenings, employees gather near a roof-deck fire pit to watch the sun set over the Center City skyline. Market Street's towers look like they're down the street.

Hoping to lure tenants with an urban sensibility to this offbeat location - the former Destination Maternity warehouse - SoNo's developers have prepared maps pinpointing the hippest restaurants and night spots in Northern Liberties, along with the estimated walk times. It's five minutes to the Spring Garden El station, 10 to the Piazza.

The question is, will anyone working at SoNo ever bother to make the trek?

The answer depends on whether the developers, Alliance Partners HSP, can find a way to overcome SoNo's unfortunate suburban template. Alliance may be marketing SoNo's snazzy offices to a bike-riding, backpack-toting urban crowd, but it is designing them for a very different constituency: the car-oriented commuter.

The $60 million project is named SoNo, as in "South of Northern Liberties," because Alliance is hoping to trade on the tantalizing proximity to that lively residential and nightlife enclave. Yet their building exists in a no-man's-land of one-story warehouses, parking lots, and drive-throughs, sandwiched among the Vine Street Expressway, I-95, and a battered stretch of Spring Garden Street.

You can find plenty of workspaces in desolate urban landscapes around Philadelphia. The wreckage is even part of the attraction.

The problem is that Alliance will keep the immense, eight-acre site in much the same state it found it. Rather than build a new, dense development on the site, it plans to reuse Destination Maternity's warehouse, a windowless brick box the size of three football fields. Employees will enter the offices from the sprawling 400-car parking lot on the south end of the building, much as they might at a typical, low-slung suburban business park.

Though Alliance intends to cut a few windows into the warehouse's brick walls and the roof, don't expect any new doors, not even on Spring Garden, a once grand boulevard the city has been prepping for a comeback.

So, no, this project probably won't transform Spring Garden Street.

Alliance's Richard R. Previdi, who is managing the office conversion, acknowledges the disconnect between reality and the image SoNo wants to project.

But even in its auto-centric form, he insists SoNo can be a catalyst to help open up the neighborhood. "We know what we have," he says. "We know it's important."

The goal is to attract four to seven companies to the building, dividing the space to suit their needs. The current design, by Seattle's ZGF Architects, is sized to house a thousand workers.

Even if just a small percentage of them venture off the SoNo reservation and into Northern Liberties, Previdi argues, the office development could help transform dreary Spring Garden Street. The design elements we associate with walkable urban places, like doors and ground-floor uses, can come later, he says.

Certainly, SoNo will be no worse than the Destination Maternity warehouse, where workers have sorted and packed clothing since the mid-'80s.

The Spring Garden corridor was once a neighborhood of elegant homes and stately institutions, like the German Society Building at the corner of Sixth Street. But in the 1960s, as I-95 pushed into the heart of Center City and engineers drew up plans for I-676, Philadelphia planners decided to clear-cut a three-block-deep swath of land between Vine and Spring Garden Streets for a new distribution and manufacturing district.

The idea was to leverage the highway access to compete with the suburbs, but it never quite worked, said Gary J. Jastrzab, now the city's chief planner. The Callowhill Corridor, as it was called, was such a dead zone it eventually was infiltrated by concert venues, such as the Electric Factory, and nightclubs. It was an attractive place because there were no neighbors to bother.

The idea of an industrial district just north of Center City may have made sense in the '60s because both Northern Liberties and Old City were still manufacturing districts. But as those neighborhoods have evolved into highly desirable residential areas, the Callowhill Corridor has become a vast canyon separating the two.

Convinced that the underpopulated manufacturing belt "can be a city again," Jastrzab says his office is working on a major rezoning that would allow dense, mixed-used development along Spring Garden. Just this week, City Council agreed to rezone Finnegan's Wake, the cavernous bar at Third and Spring Garden, for a five-story office building.

Alliance could have asked for a similar upzoning, but preferred to work with the existing building. Previdi estimates the company will take an additional two years to convert the one-story warehouse into offices.

Alliance will follow the now-familiar playbook for creative office space. ZGF, which designed the Science Center's latest buildings at 38th and Market, plans to use a mix of reclaimed and new luxe materials to create a smart, high-design space. The one addition to the old warehouse is a five-story amenity tower that will feature a "healthy-food" cafe that will be open to the public. At the same time, the developers chose not to install green features, like solar panels or a planted roof, even though it means paying a penalty for failing to meet the Water Department's storm-water-management requirements.

"We realize the whole world is becoming more urban," Previdi concedes.

It's just that SoNo isn't quite ready to join in.