The future of Dallas City Hall is up for debate. City leaders have said the cost of fixing up the 50-year-old building is at least $345 million. Some council members have questioned whether the city is rushing the process instead of implementing a more deliberative process to determine if the building can be fixed.

Former Dallas Mayor Tom Leppert says he thinks it’s time to sell the 50-year-old building and save taxpayers money. Leppert and former Mayor Ron Kirk wrote an op-ed in the Dallas Morning News on the matter.

Leppert told CBS News Texas in a one-on-one interview, it’s time to sell.

“I probably bring an interesting perspective to this issue,” said Leppert. As the former mayor of Dallas, he worked in the building for several years. He ran the largest building company in the nation and is currently chairman of the board of the largest building contractor in this part of the country.

“It is an old building. It’s 50 years old. It was inefficient running as an office building to start with. It has gotten more efficient over the years. In addition to that, it is all of suffering that you would expect of a 50-year-old building. It’s got old systems in it that need to be replaced, etc., etc…I can tell you that whenever you go into a building that’s 50 years old to do major renovations, the costs only go one way and that’s up. Once they start opening those walls, do the drainage, do the leak, repairs, those sorts of things. It’s going to be more expensive than they think it’s going to be. So, where you end up is spending hundreds of millions of dollars to kind of bring a building back, but it will never be particularly efficient.”

“It just becomes wasteful. To be frank with you, and especially at a time when there is so much office space downtown that can be utilized at a fraction of the cost. It just doesn’t make sense to do it.”

One of the arguments to keep the 50-year-old building is that it has historical value, and some say the city is rushing to judgement.

“It’s not fair to the taxpayers,” responded Leppert. “The taxpayers are the ones that are going to take the burden of that. For somebody to say, I really like the building, and I want it to hold. That’s simply not fair to the individuals. They’re going to put $500 million down and not get much out of it. I think in some ways it’s disingenuous.”

“In other ways, it’s selfish. I think you have to look at it as a hard economic decision, and that hard economic decision, I think, has one solution to it. I understand people, fall in love with buildings, etc., that sort of thing. But let’s be realistic. It’s a 50-year-old building. It’s not a 100-year-old building or 150-year-old building.”

Leppert’s suggestion is to use some of the vacant office space that already exists rather than build a new city hall. “I think you would have a number of property owners, developers that would be more than interested in engaging the city, in a conversation to take up that much square foot. The other thing is, keep in mind, it’s also valuable for downtown. We’ve got all of this empty space here. Empty space is good for anyone there. So, by utilizing that space, it’s actually going to increase or increase the occupancy rates in the downtown area, which I think will actually help all of downtown.”

Leppert said that there’s two different decisions to be made. One being what to do with city government and what makes sense for taxpayers. The second is what to do with the area. “Make this as a separate thing. And with the keeping in mind the most important aspect being the taxpayer.”

“I think it’s important to note, you’re working with a piece of land that I think has real value, potentially for a lot of different uses. Clearly one has been, aired and identified publicly as, one option for the downtown, the Dallas Mavericks. And that may be a terrific option.”

Leppert said that the area lends itself for a lot of opportunity. “And in that entire area you can do some special things. Clearly entertainment, all different sorts. And there’s a lot of people that are smart at this and they can come up with the ideas, but it doesn’t take a lot of imagination to think about something that could come out very special.”

More from CBS News