**columns”**.

**columns, shear walls** and **composite elements**.

**Columns** are defined the rectangular elements in which the larger dimension
of their cross-section is less than 4 times the smaller dimension
e.g. 400/400, 400/600, 250/900, etc. (dimensions in mm).

**Shear walls** are defined the rectangular elements with a length to thickness ratio greater or equal to 4 e.g. cross-sections 1000/250, 1500/300.

**Composite elements** are defined the elements composed of one or more rectangular elements, at least one of which must be a shear wall. Generally speaking and due to the fact that the two ends of each shear wall are locally reinforced as columns, a wall could be characterized as a composite element. For example a wall with an ”L” cross-section 1200/1000/250/250, or an ”L” cross-section 1200/700/250/250, elevator cores with or without flanges, double elevator cores with a slope on one side etc are composite elements.