The hulking block-long concrete building in the Strip wasn’t pretty, but it was iconic — the Wholey fish outlined in tiny lights grinning from the New Federal Cold Storage Building has long been a beloved part of Pittsburgh’s skyline.

Now, it looks like it’s going to be replaced by 1501 Penn, an ambitious new 23-story office building. This will add 750,000 square feet of office space to the Strip District, the hub of Pittsburgh’s booming tech sector.

The project was last before the Pittsburgh Planning Commission on Sept. 16, where the developer was urged to revise the design and return to the commission. The project even drew vocal opposition from many, including Mayor Bill Peduto, who said, “the architectural design doesn’t match the Strip District.”

After a major redesign by developer JMC Holdings and Brooklyn-based Brandon Haw Architecture, the project received unanimous approval on Tuesday from the Pittsburgh Planning Commission.

The original design was a giant glass box. While that might have fit Downtown, it drew opposition due to a perceived clash with the distinctive industrial nature of the Strip’s architecture.

Now, the massing has been broken up so that it feels less like a single, monolithic structure.

“What we thought was to create a sort of pinwheel of four quadrants with the corners just cut away very slightly, to further slender what effectively becomes four distinct volumes — four distinct towers — separated out by double-height green terraces, so that every office, user or tenant would have access to two terraces,” said architect Brandon Haw.

1501 Penn. Rendering courtesy of Brand Haw Architecture and the Pittsburgh Planning Commission.

Each terrace will be 220 square feet and planted with hardy, wind-resistant hedges to give them distinctive greenery. These also help break apart the general massing of the building.

The heights of the four quadrants of the building will range from 10 to 14 stories (atop the seven-story parking podium), stepping down in the direction of the Strip District, arranged around a central core.

Another interesting feature involves that central core.

“We see this as sort of a gently illuminated, semi-translucent beacon,” noted Haw. “It could change color with the way we light it with LED lights, for different festivals perhaps, the St. Patrick’s Day parade or whatever the occasion might be — the Steelers win, or something like that.”

“I think it would just gently glow at night. It wouldn’t be brightly lit; it wouldn’t become some sort of eyesore beacon with light pollution everywhere.”

1501 Penn. Rendering courtesy of Brand Haw Architecture and the Pittsburgh Planning Commission.

They’re going for LEED Gold environmental certification. This will include installing an “active chilled beam” system that provides better air quality than forced-air systems, along with energy-efficient lighting, reduced water consumption through low-flow fixtures and water monitoring systems, and of course, the green roof to help with stormwater retention. Energy usage is predicted to be 40% less than typical office buildings.

There will be street-level retail and a two-story bike cafe for bike commuters.

1501 Penn. Rendering courtesy of Brandon Haw Architecture and the Pittsburgh Planning Commission

The outdoor space has also undergone significant revision.

“There were issues about the project meeting the definition of urban open space,” said Kate Rakus, principal planner with the Pittsburgh Planning Commission. “Specifically, since then, in the current design, they’ve added the bleacher seating along Smallman, they’ve widened the walkway under the colonnade. And they’ve added a big mid-block accessible ramp and widened the plaza. So while staff generally still have concerns about open space under a colonnade, we are comfortable with the current design that’s meeting the definition of urban open space.”

The project could cost between $180-200 million, and the existing building could start coming down early next year. There will be structured parking for 800 cars.

“The changes that you made show that you were listening to our concerns, and that you embraced some of the limitations that those concerns might have represented and kind of turn them to amenities in the building,” said Planning Commission Chair Christine Mondor. “Whether it’s the outdoor spaces that you’ve created on the tower, or the sensitive integration of the wheelchair areas, and the steps on the ground level.”