The Sixth Street main entrance to The Curtis. Some very lucky Philadelphians will enjoy great views of Independence Square from the apartments being built on the building's east side.

Washington Square is about to get its first true 24/7 live/work/play environment with the addition of apartments to the mix of uses at The Curtis (formerly the Curtis Center), the huge (880,000-square-foot), block-long building that faces both Independence and Washington squares at Sixth and Walnut streets.

Construction is slated to begin this summer on The Residences at The Curtis, which will convert about 90,000 of those 880,000 square feet into 57 luxury apartments from the second through 11th floors on the Sixth Street side of the building.

The conversion will keep intact the grand Sixth Street lobby, with its Louis Comfort Tiffany glass mural, "Dream Garden," and preserve much of the building's original historic decor, including large windows, mahogany walls and trim, and decorative plaster medallions.

Designed by DAS Architects, The Residences at The Curtis will include a diverse mix of apartments in a variety of sizes and floor plans, ranging from studio apartments to 2,000-square-foot, two-level penthouse units with three bedrooms, three baths and rooftop terraces overlooking Independence Square.

The units will reflect the original functions their spaces once performed: those facing east will incorporate the opulent details of the Curtis Publishing Company's executive offices, while those facing south will make use of the high ceilings and large window expanses of the press room where The Ladies' Home Journal, The Saturday Evening Post and other popular magazines were printed.

“You just can’t recreate the elegance and charm of an historic building like The Curtis,” David Schultz, co-founder of DAS Architects, said in a news release. “The opportunity to combine much of the building’s original detail with more modern features will enable us to create a truly unique living experience for today’s discriminating city-dweller.”

That living experience will include the well-equipped common amenities that distinguish DAS projects. The 9,000-square-foot amenity space on the building's 11th floor will include a fitness facility, yoga studio, virtual golf, private screening room, catering kitchen, large lounge and meeting space, all overlooking The Curtis’s atrium. The firm's approach to apartment building design, which applies hospitality-industry standards to the provision of common facilities, has earned its projects several awards, including a "Property of the Year" award for The Granary at the Pennsylvania Apartment Association's 2014 Best of Apartment Living Awards. 

The Residences at the Curtis is a project of the building's joint owners, Keystone Property Group and Mack-Cali. Mack-Cali's multi-family residential division, Roseland, will manage the apartments when they are completed. The owners envision the refashioned Curtis as a "central hub" of activity for Washington Square, combining offices, residences, retail and entertainment space under one roof.