Target Center had become the elder statesman among Twin Cities sporting venues, with the 1990 building lagging in the competition to land concerts and other shows.

Target Field opened across the street in 2010. U.S. Bank Stadium opened less than one year ago on the other end of downtown Minneapolis. Xcel Energy Center in St. Paul got a major renovation, and even the Golden Gophers have a new outdoor football stadium.

But when the new Minnesota Timberwolves season opens in three months, Target Center will look as rejuvenated as the team’s new roster.

On Monday in a hard-hat walk-through for media, the concourse buzzed with some of the 300-plus workers completing a $140 million transformation that cracks the building open inside and out.

Timberwolves chief strategy officer Ted Johnson said the atrium on the northeast corner, a five-story glass facade that used to be a wall of gray concrete, will be a signature element of the renovation. The main concourse was widened and windows added with views of the city skyline and streets on the outside and the court on the inside.

A major goal of the renovation is to make the place more enticing and comfortable to fans, performers and producers. Johnson said not a single surface in the building will go untouched.

Seats are all new, replacing ones installed in 2004 in a limited renovation. Some fans already have seen the inside because their seats were displaced by some changes. Johnson, however, said that’s a small number of fans and that the configuration and capacity of the building remain the same: about 19,000 for basketball.

The bathrooms have all been redone and refinished. The biggest difference: no more troughs in the men’s rooms.

Behind-the-scenes changes are big as well.

To entice major events, the building went from one loading dock to three — an important upgrade for shows that roll 20 trucks’ worth of gear into town for a show.

A new ice floor was put under the court, at a cost of $1 million. The old floor leaked coolant.

The pros will get better digs, too, because the locker rooms have been renovated. The Timberwolves had one of the smallest locker rooms in the NBA. Their space has been doubled.

And the Lynx will now have the nicest locker room in the WNBA “by far,” Johnson said.

The higher-end suites and club seats were completed last year.

Even people who don’t go in the building will notice some of the work done this offseason.

The exterior will now be brown with new metal panels that from a distance appear to be wood and blend with the brick neighbors as well as Target Field’s natural stone and wood elements. The neighbor to the east, Block E, remains gray and steel.

Johnson said the new color allows Target Center to bridge the different styles of its eastern and western neighbors, connecting the Warehouse District and the entertainment-theater district.

As with all of the other stadiums, taxpayers are helping to redo Target Center with $74 million in sales taxes. Team owner Glen Taylor, who also owns the Star Tribune, is paying $58 million. Building operator AEG paid almost $6 million.