Solidworks routing piping in a building

Hello 

On solidworks I want to create a 3D building with pipes that goes through core drilling and changes direction right after.

I don't know if I'm doing it right?

I created a room for the building and then save 

I open an assembly then insert my building, pipe library and slide the tube 

I manage to constrain the pipe but I can't go back to the tube with an elbow?


assemblage_batiment.sldasm

See this link https://www.youtube.com/watch?v=GL0cL7MxCqA

Creation of piping library

via the right settings

@+

 

I followed the tutorial, I manage to make the parts and the measurements in the library and create a family of parts with automatic routing

but I can't draw a pipe and constrain it, whereas in an assembly  without the building yes

I don't understand?