Staircases can be indoors or outside. They can be simple, or they can be long and sweeping like in “Gone With the Wind” or tight spirals like in a lighthouse or loft. However, most staircases simply provide a way to get from one floor to another inside your house. It is fairly easy to use a measuring tape to calculate the amount of floor space you need to install this kind of simple, straight staircase in your home.
Measure from the top point of your planned staircase down to the floor along the angle you want your stairs to be. A standard domestic stairway is at a 42 degree angle, but your stairs can be steeper or less steep than that, depending on your preference, the space available and the style of your home. Make a pencil mark where your tape measure meets the floor. This is the farthest point that your stairway will come out on your floor space.
Measure from the mark you made on the floor in Step 1 to the wall that runs parallel to that mark. This is the length that your staircase will be from the front of the unit to the end of the support system.
Measure the width of the stairway. If your stairway comes down between two walls, you can measure the distance between the two walls. Otherwise, measure the width of the stairs you plan to use. This will be the width of your stairway. Multiply the width of your stairway by the length of your stairway to find the total square footage of floor space you need to install your stairway in your home.