> The only time the government lets the free market step in is when they're fresh out of stupid ideas.

True. I wonder what those stupid ideas will be this time.

I really don't know. It depends on the structure. A local mall near me has suffered from vacancies. A few years back a giant Macy's box structure went vacant. A major hospital repurposed the building as medical facilities. I can't envision each usage, but I expect the "free market"  will find entrepreneurs who will figure it out.  The only time the government lets the free market step in is when they're fresh out of stupid ideas. 

siggy47

What's your best guess as to how this plays out?

Undisciplined

econ

Get Ready for Weaker Growth and Higher Inflation. The Consensus Was Wrong.

Regarding the 1890 building, we are keeping it commercial. Retail on the ground floor, walk up offices in the second floor, and a radio station on the third floor. 
Regarding the big office buildings, I don't know. Plumbing would be a huge issue. Think of all the bathrooms. Also, the walls are plaster, which makes electrical improvements a nightmare. 