When concatenating varying properties, there may be the instance when some of those properties don't exist. There needs to be a way to test for this.
E.g. Properties:
1. Wall Type (available for "Partition Wall" & "Solid Wall" classifications)
2. Core Type (available for "Solid Wall" classification)
3. Wall Code: CONCAT(Wall Type, "| ", ISERR(Core Type, ""))
