I wrote a book about stairs. It’s a step by step guide. 

if there is a crowd of people I'll go 3-4 flights. Aside from a hospital the buildings I manage are the only 2 in town that have an elevator. I ride both of them all the time to make sure they work. We also have one elevator with a wonky self leveler that people insist will make them drop out of the sky, I ride it specifically so I get less complaints when they see me "risk my life" in it. 

if there is a crowd of people I'll go 3-4 flights. Aside from a hospital the buildings I manage are the only 2 in town that have an elevator. I ride both of them all the time to make sure they work. We also have one elevator with a wonky self leveler that people insist will make them drop out of the sky, I ride it specifically so I get less complaints when they see me "risk my life" in it. 

My hotels are 4 floors each and during the construction phase we didn't have elevators until just before opening when the inspections were finalized. Going up the first three floors was fine, but I really felt it the last flight of steps.

 

True story - while the elevators were still offline we had to bring up bags of operating supplies and equipment to the rooms. These are things like coffee makers, hair dryers, bath amenities, towels, etc.

 

To ease the pain of four flights of stairs we put groups of two on each landing and ran it like a fire brigade so people had only one flight of stairs to climb at a time.

4 is my limit depending what I am hauling.  Every one of my buddies who are retiring and are downsizing are only wanting single story houses.  My wife’s sister and her husband have an elevator in their beach house retirement home and it’s nice.