[mthd]

older office buildings, with their smaller lease depths and higher perimeter to area ratios tend to be better candidates for this.

However, as noted above in certain markets even big modern office towers are worth transforming. Here in San Francisco the former AAA headquarters at 100 Van Ness is being converted to +\- 450 condos at a cost of $200M or more. new skin, new elevators, core, etc.

we'll probably see more of this in the future as urban cores drift back to being more fully mixed use, but it will always vary with cycles in the market. Sometimes office is hot when residential is not, sometimes vice versa, sometimes they're both hot....