You can take a look at realtor websites and see what's for rent in the area you're buying and have an idea.Also keep in mind, the non-separated utility meters (water, heat, yard maint) is paid for by the landlord in MF. 

There was no plumbing (stolen), outdated electrical, no heat/AC, unfinished attic and a bad layout.

The first house has oil heat.

Some upgrades, such as replacing windows with double-glazed windows are essential to lower their heating bills and ensuring that tenants have enough to live on and pay the rent.

All new electrical/plumbing/furnace/water heating and some roof repairs.

Especially because all tenants wait until the last minute so all the HVAC contractors end up with a 2 week wait list where tenants have no AC or heat depending on season.

Whose paying for the heat? 

When those spaces are properly permitted to be living space, they then appear as 'finished' spaces and are reflected in the 'heated' or 'living' square footage. 

As Chris added, fire escape, AC/heat ducting. 

Atleast that way she’s heating the house for me