It was, at first, an ordinary Philadelphia development story.

When Southern Land Co. made its second foray into Philadelphia in 2015, the Nashville-based developer had a big idea: It would purchase the last developable swath in Rittenhouse Square, 1907-1915 Walnut St., and build a glass skyscraper there. To achieve its vision, the company said, it would demolish three historic buildings and replace them with ground-floor retail. On top, 425 apartment and condo units would occupy a 599-foot tower — making it the tallest residential-only building in Philadelphia's skyline. Underground, plentiful parking could be accessed from a less-busy Sansom Street.

Southern Land — which at the time was finishing its first Philadelphia project, across town in University City — believed the planned development at 1907-1915 Walnut St., would be transformative for the Rittenhouse Square neighborhood.

There was one problem: Their plan wasn't the kind of transformation residents were seeking.

According to complaints in 2015, the proposed all-glass tower was out of place with the neighborhood's centuries-old architecture. Residents questioned why the historic buildings on the 1900 block of Sansom Street — the Rittenhouse Coffee Shop, the Oliver H. Bair Funeral Home, and the Warwick apartments — had to be razed. The garage on Sansom Street, some thought, would derail efforts to make the corridor more walkable. Many, meanwhile, simply took issue with the building's size.

If Southern Land were a different developer, and if Rittenhouse Square any other Philadelphia neighborhood, this story likely would have ended the way countless others have: Both sides dig in, threats are made, a century-old building comes down, perhaps, or lawsuits are filed. Most times in Philadelphia, both residents and developer leave embittered and exhausted, neither getting what they want.

Rittenhouse Square residents knew that game firsthand, even at this site. In the late 1990s, the neighborhood vehemently opposed a plan by the Philadelphia Parking Authority and Moreland Investments to build a movie theater, a Stephen Starr restaurant, and a nine-story parking garage on the site — and won. They had the connections and resources to fight again for the 14,280-square-foot swath, which had sat vacant for years after a 1994 fire.

Still, Rittenhouse Square neighbors chose a different tactic when Southern Land bought the land in 2015 for $30 million — one that they had tested just a few months before. Rather than working against the development company, residents wondered, could they actually work with it? So, they dropped their pitchforks and took up handshakes, abandoned their lawyers and brought in architects.

Turns out, it worked.

Rather than using the traditional registered community organization process, the neighbors formed a "stakeholders committee" to negotiate with Southern Land. To join, businesses, homeowners associations, and even individuals could buy "shares" for $1,000 each, which would allow a vote on the final project design.

In the end, the committee amassed $21,000 — a sum that Southern Land matched. They used the money to hire local architects to advocate for residents.

It was a daunting prospect for Southern Land, which had faced little resistance when it proposed 3601 Market, a luxury apartment tower in University City, only a few years before.

"I thought, 'This will be really rough,'" said Tim Downey, the CEO of Southern Land. "We have 10 different community groups that are going to be meeting with us at one time and everyone will have a different opinion. It was scary. I really didn't know what to expect."

"But when [they] called me and said, 'Here at this group, we don't lawyer up, we architect up,' I thought, 'That's pretty unique.'" Downey continued. "And from that moment on, I worried a bit less."

The strategy had worked once before, at 19th and Chestnut Streets, where Pearl Properties had planned to build a tall tower where the 1920s-era Boyd Theater once stood. Using their stakeholders committee, residents hired local architect Cecil Baker to negotiate a different approach. Ultimately, the tower was shortened and the design improved. The 24-story apartment tower, dubbed the Harper, is currently under construction.

"It became a model to take up with [Southern Land]," said Rick Gross, who founded and spearheaded the committees for both projects. "And we are looking at it as a template with development going forward."

Across economically diverse Philadelphia, the poorest big city in America, convincing residents that they should buy into having a seat at the table — literally — would likely be a tough sell outside of Rittenhouse. Still, Gross said, it was an effective strategy with Southern Land. In initial meetings, the company stressed it wanted to create something "extraordinary," Downey said, and build a tower tall enough to provide a financial return. The stakeholders wanted improved architecture, a different parking entrance, and the historic buildings saved. Most notably, the committee told Southern Land, they wanted some affordable housing.

In the end, Southern Land decided it could save two of the historic buildings entirely — the Warwick apartments and the Rittenhouse Coffee Shop — and could even incorporate them into the project. Consulting with Cecil Baker and John Randolph, local architects hired by the stakeholders, Southern Land changed the design of the building, giving its Walnut Street entrance a look that better blended with the neighborhood, plus a more dynamic tower design. They moved the underground garage onto 20th Street, saving Sansom and Moravian Streets from heavy traffic.

Plus, Southern Land said, it would include affordable housing, in exchange for a density bonus.

"There is a real workforce housing crisis in this country for people who work so hard for the city or the police or as waiters and cooks in these nice areas, but can't afford to live in them," Downey said. "To include them in the development … it makes the community more diverse and more interesting."

Southern Land plans to put eight workforce housing units in its tower, which will stand at 599 feet — still keeping it as the tallest residential-only tower in the city. An additional 30 units will be available as affordable housing in the now-vacant Warwick apartments on Sansom Street. According to Downey, Southern Land will either develop and manage the Warwick apartments itself, or give Project Home, a Philadelphia nonprofit, $4 million to do so. Details on that arrangement, Downey said, are still being worked out.

Southern Land's workforce housing will be available to residents earning 60 to 80 percent of area median income, or $36,708 to $48,944 for a single person.

"At the end of the day, this project is better because we have an affordable component," said City Council President Darrell Clarke, whose district includes Rittenhouse Square.

"And one thing that stands out is that this is self-subsidized,'" he said, calling it a "template" for affordability in privately developed housing.

As for the rest of the project, Southern Land's tower will stand 48 stories tall and include 74 condominiums on floors 27 through 48, with 177 market-rate apartments below. The 26th floor will have a posh amenity floor for condo owners only, featuring a pool, sauna, and fitness center, among other attractions. Renters and condo owners will share other amenities in the development.

The condo portion of the tower — called the Laurel — will have unobstructed views and ultra-luxury finishes, such as marble walls in the bathroom, said Brian Emmons, Southern Land's development manager in Philadelphia. Each unit is expected to sell for more than $2 million.

So far, the company has received 12 deposits, with agreements of sale ranging from $2.5 million and $6.5 million. The tower's two 9,100-square-foot, full-floor penthouses remain available, and are currently designated as raw space.

The tower's estimated completion is 2021.

"The most important thing that we are working on right now is finding good commercial anchor tenants that are going to be appropriate for the building and add value," Emmons said. "Being the last building on the square, it's so important that we do this right, and we are being very careful and very conscious of that."