# Wall Determines Implementation

Since this is the recommended workflow, it should be examined and described in greater detail. It is more flexible and, depending on the preparation level of the pre-run file, faster than the old method. However, it is crucial that the pre-run file is prepared accordingly.

Necessary settings in the HRB pre-run file:

* In the pre-run file one can, via 2.1, *Wall composition* also define an execution. This should be done to ensure that the dynamic preview within the HRB editor functions. Here one can enter fixed values that approximately correspond to the later layer thicknesses. When populating a wall, the layer thickness set here no longer plays a role, since the layer thickness of the populated wall is adopted.
* For the thicknesses of all materials, use system variables that indicate the thickness of the layers rather than user variables. For example, the studs of layer 0 receive the thickness "Lp0" and a panel of layer -1 the thickness "Lm1". This informs the HRB interpreter that, for the component thickness, it should take the thickness of the corresponding layer of the populated wall.

Another helpful point is the basic layer structure of the HRB pre-run file. As an example, the supplied pre-run file A\_Dietrichs\_HRB14 is used. Here, for instance, a plaster layer was defined for layer -7, while a counter battens layer was defined for layer -5 and formwork for layer -6. In a wall you would never have formwork and plaster at the same time. If in the entered wall layer -7 has a thickness of 0.0, no plaster panel will be generated. However, if layers -5 and -6 have a thickness greater than 0.0, then the counter battens and the formwork will be generated. Thus, in the pre-run file you can provide various layers and control whether the respective panel is generated by the thicknesses of the layers of the populated wall. For this reason, the supplied wall executions also repeatedly include layers with a thickness of 0.0.

It is therefore advisable to consider in advance which layers you might need and how these could/should be distributed across the wall.
