Editing Master Data: Asset Data 
A property or building can be assigned more than one asset. To specify the account determination, you have to identify one of the assets as leading.
If you want to access evaluations for depreciations and retirement postings of objects in the RE information system, you have to assign an asset to the objects.
Prerequisites
Customizing settings
Main Usage Types); the account determination for the debit position of lease-outs may depend on the main usage type; if no asset is assigned to the building or property, the main usage type is derived from the asset class of the leading asset according to the rule defined in Customizing
Master data of leading asset
The number of the business entity is identical to the asset number of the leading asset.
Procedure
Proceed as follows in the master data of a building or a property:
Enter your required assets in the Asset field using Multiple selection.
The dialog box Assigned assets is displayed, offering the following editing options:
The Property, Building text and Main usage type fields are automatically updated under the General Data tab depending on the asset class.