Before you start measuring, it's important to understand the goal. A staircase is not a flexible component that can be adjusted on site – it's a precisely manufactured, rigid component. However, the space it's installed in is almost never perfect: walls are often not exactly vertical and angles are rarely exactly 90°.
Your task is to capture this reality exactly. Every deviation, even just one centimeter, massively affects the later installation and the precise fit of the staircase. We need your measurements to construct the staircase precisely for this imperfect space, because it cannot simply be "squeezed in" later.
The measurement therefore always begins with analyzing the space. Imagine projecting the outline of the stair opening from above exactly vertically onto the floor of the lower level. This creates an "ideal box". Your measurements reveal how much the real walls deviate from this ideal box. These deviations flow directly into our construction and determine the perfect fit.