Multiple internal partitions on a single plane: issues and solutions
Posted by Andrew Bairstow on 29-Mar-19 10:18 AM
DesignBuilder cannot assign more than one partition construction to a single internal wall plane. This behaviour can cause issues for cases when there is more than one partition type on a single plane.
This could for example be a "heavy partition" at ground floor level aligned with a "light partition" on the first floor.

This Knowledgebase article looks at the issue and how to circumvent it using a practical example

This example deals with a fairly common scenario: Large workshop space with office in corner with a store room above.

It is not unusual that the partition between the office and warehouse is different to that between the store and warehouse and thus it will be necessary to make separate assignments for each of these (one, likely, being inherited from building or block level). A common mistake is that once the partition from "Unheated Store" side is overridden, the change will be applied to the whole partition on the Unheated Warehouse side, including the part adjacent to "Heated office" zone.
This is expected (though perhaps not ideal) behaviour.

Important notes:
1. For partitions which arise at the junction of blocks it is best to make the assignment at surface level.

2. Resetting of a partition which is shared by two blocks may not be automatically assigned to the other block as these are at the same hierarchical level. Thus it is always advisable to refresh the geometry afterwards using the Rebuild command.

To prevent any potential issues in the case where different partition constructions need to be applied to surfaces that are adjacent to a single larger surface, we suggest the following approach:

Represent building using two horizontal storey blocks

-    Create two "storey" high blocks to represent the building
-    Draw a "Hole" in the floor between bottom and upper warehouse parts
-    Merge warehouse zones using "Merge" command
Ground Floor:

First Floor:

Building level:

Since the warehouse is now created using two separate blocks, each part of the partition between workshop and office / store is treated independently.

The “Lightweight” partition can therefore be now applied only to upper “Store” zone without having any impact on the bottom part of the construction.

Please note this procedure is only necessary for cases where different partition constructions need to be applied to surfaces that are adjacent to a single larger surface.

Related articles:
EPC Convention 4.08 Modelling a zone within a zone