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).
The terms run and rise refer to the measurements for each individual stair. The ideal slope is 30-35 degrees. As a rule of thumb, if you use a 7-inch rise and 11-inch run for each step, that slope should be simple to maintain. Most codes require a 3-foot passage width, but you can make them wider. The parts of the stairs you walk on are called treads, while risers take their name from the rise measurement.