Indoor stair dimensions
When you build an indoor staircase, you will need to comply with your local regulations and building codes.
Stair measurements
We will start with the treads. They will need to be no less than 11 inches in width to allow proper foot hold.
The total distance from the bottom and the top of the stairs doesn’t need to exceed 12 feet. Landings must not be smaller than 36 inches in width. There is no regulation for the number of stairs.
Balusters and railings
The gap between the balusters should not exceed 4 inches for safety reasons. Also there should be one baluster or rail for every stair tread. The measurements for the height can differ from area to area so check the local codes.