Use the Expression Editor to build expressions that evaluate properties. Enter property names directly into an expression, or select them from the Expression Elements Menu.
If you enter a property name that is not in the Property list, validation may issue a warning. However, if that property exists in your data store, the expression may still be valid when it's run. You can also view valid property values using the Values Pane. See: About the Expression Editor for more information.
Concatenate (combine) properties in the original data store to map to properties in the model.
in the Roof Height field to open the Expression Editor.