2756
Generally, a stair lift can be installed professionally for about $3500 for a standard lift, on a straight set of stairs and only a single flight. Turns and non-standard stair configuration will increase the price substantially.
a ladder or a flight of stair
Flight of stairs and Fleet of ships.
4 feet
12-17
A flight of stairs in it's entirety is a staircase
stair and stare
A hand truck with a stair climber built in.
It is one word "staircase" (open flight of stairs, usually with rails).
Please clarify what exactly you want to calculate.
A monobeam stair is a stairway that is supported underneath by a single beam. This single beam, or monobeam stair works the same as any other stair that has two stringers, one up each side, on which the treads are laid and the risers are attached. The monobeam construction can add an element of "freedom" to the stairs, and it is easier to create the illusion that the stairs are "floating in air" if the whole project is done in a clever way. Got a link to a picture of a monobeam stairway, if ya want it. And there are more on the web....