One City apartments in Philadelphia, PA
One City, by BLTa 2
One City, by BLTa
One City, by BLTa 1
One City, by BLTa 3
One City
One City, by BLTa 4
One City 1

One City

Philadelphia, PA

“This project returned a masterpiece to its proper prominence in a neighborhood of amazing early skyscrapers.”

In 1899, the headquarters of the United Gas Improvement Company opened at 1401 Arch. UGI founder, Peter Widener, hired the renowned firm of the Wilson Brothers to design the 14-story building a block north of City Hall. The Renaissance Revival, steel-frame structure was clad in brick and terra cotta and was one of a number of impressive office buildings erected at the time. To convert it to apartments without losing the historic character, all 1,100 original double-hung windows were refurbished. Facade renovations included new copper flashing, masonry and terracotta repointing and repair, the preservation of Samuel Yellin’s monumental cast-iron gates, and new amenity spaces on the roof. Removal of drop ceilings, vinyl flooring, and commercial carpets exposed historic coffered ceilings, marble and travertine columns, ornate plaster, and historic millwork.

This project was completed by BLTa prior to becoming a Perkins Eastman Studio.

Project Facts

  • Client:

  • Alterra Properties
  • Size:

  • 221,500 sf | 20,577 sm
  • Services:

  • Architecture
  • Project Partner:

  • Eileen Tognini, consulting interior designer
  • Markets:

  • Renovation + Historic Buildings, Residential
  • Region:

  • United States
  • Studios:

  • Philadelphia


  • 2021 Preservation Alliance Grand Jury Award