So at the time they were built, if they had specific stairway width etc.. they should be all set since they were made before new regulations were introduced 

Hi @Rudy Manna:Generally stairways to an attic don't meet building codes for the attic to be livable space.

The house need to replace roof, siding, and outside stair way have some damage.

You'll have to pay electric for the common areas, there may be holes or marks in the stairway walls that no one will fess up to, insurance will be higher too.Good luck and let us know how it goes!

The guy I went with did an excellent job - essentially, he tore out all the OSB, tore out the ceiling, tore out the carpet on the stairway down to the basement, etc.

We will call the second floor tenanats and make sure they are not smoking in the hallways or stairways. 

@Franchesca Ramaker,It's not locality specific, though you'll need to research the landlord / tenant laws and building codes in your area.In general, if the units are "sub-metered" - each unit has its own water, gas and/or electric meter, then each tenant pays their own and there should be a common area meter in some cases for stairway lights, outdoor lights, lobby / vestibule heat, common laundry, etc.Where I'm living now, I pay my own gas and electric, and water / sewer / refuse are included in the rent.

I had to replace a 2nd floor window that had been there for 100 years... modify all the stairways and deck railings... hard wire smoke detectors and on and on...

If I can see a door and back stairway work, that will help. 

.• Floors, stairways, and railings in good repair.In addition to these requirements, each rental unit must have all of the following:• A working toilet, wash basin, and bathtub or shower.