You could say the young proprietors of 12welve Eyes Brewing have a vision for St. Paul's Lowertown, and specifically its historic Pioneer Endicott Building.

12welve Eyes is so named because of its bespectacled trio of founders, all childhood friends from Shoreview now in their mid-20s. Like many young craft brewing entrepreneurs, they're essentially launching their first business with the beer operation.

But they have plenty of confidence it will not only succeed but add something new to the burgeoning Lowertown social scene when it opens, which is now expected to be in midsummer.

Much of that firm conviction stems from the undeniable attractiveness of 12welve Eyes' pending location at the Pioneer Endicott, a pair of 1890 office towers converted in 2012 into an apartment and retail complex. Owners Rich Pakonen and Clint Blaiser spent $45 million on the renovation.

The combination of stunningly preserved late 19th-century architecture, the convenience of the nearby Green Line light rail and the surge of new residents seeking downtown apartments with character made the Pioneer Endicott a hit. In addition to its 234 apartments, the connected buildings host a pair of retail businesses on the skyway level: Legacy Chocolates and Revival Wine, Beer and Spirits.

The final frontier in its conversion remained its sprawling basement, tens of thousands of square feet that, over decades, was cut into smaller spaces. Easily the most attractive of them was a 2,500-square-foot garden-level space, which boasts its own separate, walk-down entrance into the Endicott Building from the 4th Street sidewalk between Robert and Jackson Streets. Despite being below street level, its large windows allow in plenty of light.

That was the hook for 12welve Eyes managing partners Elliot Grosse and Karl Eicher, both 26, who say they saw in it a chance to create something they contend St. Paul currently lacks — an intimate, cozy, neighborhood-oriented craft brewery taproom.

"What we want to be first and foremost is a hub for the people who live in Lowertown, and for those who work here and in downtown St. Paul," said Grosse during a tour of the new space this week. "We want to be a comfortable place for them to hang out and enjoy a brewery that constantly rotates a selection of great small-batch beers."

He and Eicher figure the visibility of the taproom space from the street and passing light rail line will signal the presence of a new neighborhood hangout, but where things really get interesting for 12welve Eyes is the part most customers won't see: the brew room. Because of the compartmentalized nature of the basement, their five-barrel brewing system is being installed down the hall in what used to be the Endicott Building's boiler room.

The buildings' hookup to downtown St. Paul's district heating system decades ago made the old boilers unnecessary. As a result, in the most costly and unusual part of the enterprise, Grosse, Eicher and building owner Pakonen carved out a suitable space for the brew room.

This week's visit revealed a somewhat eerie, deep underground chamber with an 18-foot ceiling, which in this early stage of construction has a dirt floor in which trenches are being dug for a drainage system. Its conversion into a modern brew room will make 12welve Eyes unique in the Twin Cities, possibly in the country, Grosse said.

"With breweries, you're usually looking for contiguous spaces of at least 5,000 square feet in an industrial building, with the tasting, brewing and cooling room elements all together," he said. "But here we've got them in three separate-yet-connected spaces in the basement of a historic building. That's something unlike anything the Minnesota market has seen."

"What's also different is that because our taproom space is separate from the brewhouse, it has a low ceiling to create an intimate rather than industrial feel, and can be designed for better acoustics," Eicher added.

Don Jacobson is a freelance writer based in St. Paul. He is the former editor of the Minneapolis-St. Paul Real Estate Journal.