Example one property I saw became a bank and a dentist office side by side with national tenants.Just like any asset class some tenants will not make it for projects.

I would think 500 units and 2 years if the units are wide range of ages (hardscape lasts a long time (30 years for asphalt, cement maybe 60 years) but is expensive, ditto foundations) could suffice. 

Especially if said landlord is a doctor or a dentist with millions in other assets?

Bi level ground cement treatment system.

There's the obvious such as: choosing a good location, conducting a title search,  and making sure you don't go over your set price; however, I was looking for best practices on avoiding duds properties (e.g. properties with folks who won't move out, or properties where the previous occupants put cement down the drains, etc.). 

If insulation grants are available, you may find it cheaper to tear off the siding, insulate and re-side with something from vinyl siding to shakes or fiber-cement boards.

I am on the 2nd (porcelain) tile floor in my own kitchen over 20 years, and even with 3/4 subfloor, cement board, high strength thinset with flex agent, there are still about 6 or 7 hairline cracked tiles from where something heavy has been dropped on them - errant can, hot pot, milk jar, etc.

I’m sure tourism will be back but this experience has just further cemented some things that we already were thinking about.

Fyi There's very very nice cement paint where you throw sprinkle flakes.

You might talk to family, friends, doctors, dentists, local business people, etc.