Don Dethlefs, CEO of Denver-based Sink Combs Dethlefs, mentions more-stringent seismic requirements in California as adding to the costs of stadiums there (and in Las Vegas and a few other locales), as well as factors that influence costs on a case-by-case basis.
Target Field in Minneapolis, for example, was "wedged in by viaducts on a very tight site," he
notes, while even a new Vikings stadium located on available land next to the Metrodome will require a phased demolition and construction that will surely add to costs there.
Added to which, Dethlefs
says, "Even the spaces around the buildings are getting more lavish; people are spending way more on plazas and other finished outdoor spaces.
"It's the most expensive place to build," Dethlefs
Were you to add up all the costs associated with each of these elements, it probably still wouldn't explain the final cost of most of the stadiums mentioned here - with the possible exception of Cowboys Stadium. ("You see where they spent the money in Dallas," says Dethlefs