A new proposal: Down goes the four-story TCF Bank building in downtown Minneapolis, up goes a mixed-use skyscraper 50 stories tall. Is it time to call in the historic-preservation brigade? It seems like every other month we lament the loss of smaller, older buildings, and wonder if we’re losing our heritage to big new developments.

This is not one of those times.

The TCF Bank building certainly sums up the 1970s. Half a block of dark brown brick. Could be a bank. Could be offices. Could be the Gerald R. Ford Mausoleum. Could have been beautiful; there’s nothing objectionable about large quantities of brick, and dark hues can project a certain earthy honesty. But so does a cow pie.

The problem with the TCF building always has been its big, dated brick arches, which looked like a classical touch done on the cheap. The top two floors are recessed behind the columns, creating a realm of shadows and gloom appropriate for the First Bank of Mordor.

The 17-story TCF Tower is not part of the proposal. Too bad. It’s the sort of building you found in abundance in suburbs in the ’70s, scaled up four times. Brick and horizontal bands of mirrored dark glass — real estate stacked up until it ends. Could be three stories, could be 30. At the fifth floor, it widens out, which makes it look like Fatty Arbuckle sitting on a footstool. (That was another hallmark of the ’70s: Buildings got wider as they rose, as if the architect had been staring at mushrooms all day.)

The TCF Tower’s slight bulge looks as if they ran the numbers, figured out what the steel structure would hold, and bumped it out for 3 percent more rentable space.

How to work around the remaining tower? That’s the problem. The portion of the TCF complex slated for demolition may be stale cake, but at least it’s a small portion. The TCF’s low height gives its neighbor, the Foshay, space to rise and command its quarter of the block. Fifty stories rising next door might wall off the Foshay, make it look penned up. On the other side, the new tower structure incorporates the TCF Tower, or comes so close that people will be able to lean out of one building and ask their neighbor if they have any Grey Poupon. It’s a challenge.

Whatever they build, it probably won’t have an empty atrium. If you’ve visited the TCF building, you know it’s not solid offices. There’s a four-story open space. At present, with TCF’s workers decamped to Plymouth, it is one of downtown’s most bereft locations — no benches, no chairs, no coffee cart beneath a colorful umbrella, no vegetation. A rectangular brick fountain is dry. A huge greenish sculpture on the wall looks like a mass of barnacles fastened to a rusting ship.

Visitors may wonder why on Earth there’s a glass box set into the wall with a picture of Gopher sports — well, once upon a time it was an aquarium. Once upon a time the fish swam and the fountain ploshed and noonday workers had lunch in the big brown barn. But even then it was too dark, despite the skylight above; you just can’t pile up that much brown brick without making you feel like you’re inside an unwashed coffeepot.

Perhaps it worked when brown and beige were the popular hues for corduroy suits and Qiana shirts, but it dated quickly, and unlike other spaces downtown whose styles fell out of favor, nothing was done. But at least you could sit there on a quiet afternoon and woolgather awhile before heading back into the Skyway Habitrail.

The new tower will add to the skyline, but it won’t define it. Apparently, architects and developers who want to build higher than the IDS are regarded as dangerous maniacs, as the tale of the 80-story proposal on Nicollet seems to suggest.

At least the building will incorporate housing, a hotel and offices — something Minneapolis hasn’t yet seen in a tall tower. It’s a cosmopolitan concept that adds more life to downtown. Unlike a mirrored shaft that empties out its citizenry at 5 p.m., it’ll have residents both permanent and transient.

Will you go there? Will anyone be welcome? Depends. It would be nice if the new tower had an atrium with TCF’s size, and Foshay’s elegant hues and motifs. The TCF’s interior spaces may not be perfect, but it was still a place to go on a cold downtown day. Even the dullest building may give you reason to mourn its demise.