"Buildings" in Deep Space are attached to a project.
You may have a hospital project that includes 5 or 6 different buildings.
Various Deep Space dashboards are able to refer to "Buildings" data for analysis purposes.
Generally, you should:
Create Buildings for your Project
Apply Source Files to specific Buildings (where applicable)
Use DS Command > Projects > Buildings
Allocating Your Models to Buildings
Use DS Command > Files > BIM Files >
Filter by Project and Search the Filenames:
Multi-select and use Update:
Set your Building and choose Update Now:
Create them at DS Command > FM > Sites:
Connecting Your Building to a Site
A "Site" in Deep Space can be used in FM workflows.
When viewing a Building in DS Command, you choose to allocate it to a Site as shown: