Just as a matter of passing interest . . . . . . about our embassy buildings abroad
The State Dept has a strategy in place to sell our older center city properties for new properties outside the most expensive (and vulnerable) city center locations. The older embassies would be far too costly to retrofit for the latest security needs, to say nothing of lacking the appropriate blast setbacks from the closest point of uncontrolled approach by a car or truck bomb.
The financial reasoning, which has thus far shown to be viable, is that the center city properties have significant value, which allows the new property to be acquired, often with a lot left over. The cost of a new structure that meets current standards is almost always less than the cost to retrofit an outdated building. The net net of the strategy is that we get a new building, at a more secure site, for the same or even less money than a retrofit.
I'd say that's a pretty good deal.
This policy goes back to GWBush. Of course there has been ongoing fine tuning, but that's the genesis of it all.