The Lillian Marrero Library's Grecian columns and bright white limestone stand out on the corner of Sixth Street and Lehigh Avenue, in one of the poorer zip codes in the city, dotted with vacant and crumbling rowhouses.

A $6 million renovation will expand the historic building, due to reopen in the fall, and transform it into more of a community space. An all-glass extension will allow neighbors to see directly into the building, as a way of connecting it to the neighborhood.

"This is Sixth and Lehigh. People living in this neighborhood are good people and they struggle every day to make their way in the world," Mayor Kenney said after touring the construction site Friday. "To have something as beautiful as this, as accessible as this, and as educational and mind-expanding as this, is a wonderful thing for people to have in their neighborhood."

The library is one of four Free Library branches currently undergoing major renovations that predate the mayor's Rebuild initiative. Branches in Tacony, Mount Airy, and Logan are also under construction. Kenney said the upgrades preview what's to come with Rebuild, a program targeting 150 to 200 parks, libraries, and recreation centers across the city.

"Every neighborhood in our city matters and every neighborhood in our city should have facilities like this for their children," Kenney said.

The Rebuild projects will be funded with a bond financed through the sweetened-beverage tax. The tax, which passed in June, received renewed scrutiny this week from beverage company employees, who said their wages have taken a serious hit.

Kenney dismissed those complaints outside the library.

"I don't know if that's accurate or not," Kenney said. "Most of what the soda industry put out during the soda-tax campaign was specious and wrong. ... All I know is there are almost 2,000 kids today who are getting a pre-K experience that will lift them out of poverty."

When the Lehigh Avenue branch, designed by architect George Hewitt, opened in 1906, it was the largest public library in the state and one of three in the city funded by Andrew Carnegie. Within the first few days of its opening, the shelves of children's books were nearly barren due to popularity, according to library archives.

One hundred years later, the reimagined space will focus less on books and more on public spaces.

The redone library will include a corner for children and another for teens, an expanded computer lab, and spaces for tutoring, mentoring, and meetings.

A central living room will consist of chairs and tables for people to sit, read, and study, said Jim Keller, the project designer.

Outside, a front lawn will feature a platform and small amphitheater for poetry reading, children's story time, and outdoor space.

The library was named after Lillian Marrero, a community activist and librarian at the branch, who died in 2005.

The structural problems with the 100-year-old building mimic issues in branches citywide, Free Library director Siobhan Reardon said.

"In this particular building, the roof leaks and the gutters are inside the building, so whenever there was a leak, you could see it coming down the walls. And the boiler was ancient," Reardon said. "Now, this whole building is going to be completely fixed so that we should never close here, and it's just a gift back to the public, who deserve to have this space."