While not new, since the concept was already described by Christopher Alexander in its architectural theories, it only gathered some traction in programming due to the publication of Design Patterns: Elements of Reusable Object-Oriented Software book in October 1994 by Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides, known as the Gang of Four (GoF), that identifies and describes 23 classic software design patterns.
Use a calculator to calculate the stair riser length or the number of steps you'll need. Divide the height from the first floor to the top of the second floor by a predetermined height of your choice for the riser. The typical height of a riser is 6 or 7 inches (15 to 17.5 cm).
For the safety reasons and for the comfort of usage, stair measurements are recommended to follow some guidelines: The run length should be 9 inches (23 cm) or longer for enough foot space. The riser height should be 8.25 inches (21cm) or lower. The nosing protrusion length should be 1.25 inches (3.2 cm) or lower to prevent tripping on the nosing. The headroom is recommended to be 6 feet and 8 inches (203 cm) or higher. The stair width is recommended to be 35 inches (89cm) or longer. The height of the handrail, measured from the nose of the tread, is recommended to be between 34 and 38 inches (86 to 97 cm). The comfortable size of handrail diameter is between 1.25 and 2.68 inches (3.2 to 6.8 cm).