Change the project standard that determines the specific parameters used for calculating and reporting building part data.
Buildingbook Extension panel 
(Calculation Settings).
The current project standard displays at the top of the Calculation Settings dialog.
An additional warning prompt displays to ensure you want to make the specified changes or not. If you change the project standard, all existing Buildingbook data is removed from the project (with the exception of assigned materials if selected in the Change Buildingbook Standard dialog).