It's been well-known since at least the time when Peopleware was first published (so at least several decades) that open-plan office designs don't actually save

It's been well-known since at least the time when Peopleware was first published (so at least several decades) that open-plan office designs don't actually save money. Not even in dense urban areas. Not even over short time periods like 1 year. In order to believe that they do, you essentially have to have such an unrealistically hyperbolic discount function that you believe marginal productivity of your workers is nearly worthless compared to the up-front costs of the real estate.