Model data that applies to internal surfaces and openings is generally not available at zone level. This helps to avoid ambiguity when different settings are made in adjacent zones.
To understand why this is the case, consider a partition between zones A and B. If "partition type 1" is selected as the Internal partitions model data in zone A, and "partition type 2" is selected in zone B, the inheritance rules indicate that the shared partition could either inherit from zone A ("partition type 1") or from zone B ("partition type 2"). DesignBuilder prevents any such uncertainties from entering into the modelling process by hiding the Internal partitions setting at zone level.
Surface level Internal partitions model data settings are instead inherited from block level, however note that settings for inter-block partition surfaces are inherited from the building level for similar reasons.
These same rules apply to the following model data settings:
All data under Internal windows header
All data under Doors > Internal header
All data under Vents > Internal header
The general rule is that if you need to apply different settings for internal partitions, glazing or any other data listed above in different parts of the model (i.e. you can't just make a building level setting to apply the same change across the whole building), then it is best to make changes at surface level. In this case the change is automatically applied to the corresponding surface on the other side so there can be no ambiguity.
Tip: If you find that the above rules are slowing down your modelling process because you need to apply multiple different settings to internal surfaces or openings across your model, then you should consider using the Model data grid tool to speed up the process by making changes to multiple surfaces at once.