Back when this rumor came out, I did a pretty comprehensive analysis of the zoning (for my own knowledge), but I have no idea where it's at to reference. From what I remember, the zoning for the current Columbia site would allow for the stadium, however they do it (renovation/new), because they are a University. My assumption would be that the University actually owns the stadium with the team holding an XX-year operating lease (and the team pays for all construction), and because of that arrangement, the neighborhood wouldn't necessarily have any firepower to push back (University's are highly untouchable with how they program their land use).