Twin Cities Public Television's 25-year-old headquarters and studio building in downtown St. Paul has always had a pretty low profile despite being the nerve center of a highly visible media operation.

Its only real public-facing presence has been a small lobby off its skyway-level entrance. And even that was on a quiet spoke of the city's enclosed walkway system.

But much has changed since its construction in 1989. Lowertown has emerged as a full-fledged cultural phenomenon, the Green Line light rail now runs right by its front door, and the nearby Union Depot has been transformed into a transportation and community hub.

This fall, after 12 years of planning and dreaming, TPT finally began renovations that will transform the dated interior of its 105,000-square-foot headquarters, opening it up to the public and tapping the new creative energy and traffic of the surrounding Lowertown neighborhood.

"Years ago, we were kind of anticipating the revival and renaissance of Lowertown, and so we began planning for this," TPT President and CEO Jim Pagliarini said during a tour of the renovations this week. "What it represents, really, is the tangible evidence of a new covenant we've committed to with our nonprofit partners. For us, it's about openness, collaboration and community."

In all, the renovation work will cost about $20 million, with $11 million of the total coming out of a $40 million capital fundraising campaign led by General Mills Inc. CEO Ken Powell and retired Best Buy Co. Inc. CEO Brad Anderson. The other $9 million is from state bonding money. The renovation team is led by project architects the Cuningham Group and general contractor McGough Construction.

A 5,000-square-foot space on the building's 4th Street level — previously an underused storage area — will be transformed into TPT's new public entrance, doubling as an acoustically engineered performance space. Pagliarini said the big new room will be programmed by TPT's nonprofit partners, such as the St. Paul Chamber Orchestra and the Schubert Club, and will mostly cater to downtown lunchtime audiences.

"The idea is to try to really make this as accessible as possible, and my vision is that people bring their brown-bag lunches, hear something nice, and really feel good about being a part of this community as well as about TPT," Pagliarini said.

The new space could also be used by TPT itself to host viewing parties for new shows, a season premiere of "Downton Abbey" for instance, or for other public functions.

The other main aspect of the project is to rehab TPT's 65,000 square feet of office space, which has necessitated a move for employees into temporary quarters in a neighboring building until the project is completed next fall. While that has caused some consternation for workers, the need to replace the 1980s cubicle-and-narrow-hallway style of office design with a modern layout was overwhelming, Cuningham architect Eric Lagerquist said while standing in the middle of what is now a huge open space flooded with sunlight.

"There are some great windows in these offices, but the natural light was always blocked by the first row of cubicles," he said. "We're tapping the trend toward open, digitally connected, collaborative work spaces with this office redesign. Before, there were really no connections between people, who were separated into boxes."

Don Jacobson is a freelance writer in St. Paul and former editor of the Minnesota Real Estate Journal.