I'm creating a procedural building and therefore I made some digital assets like window, balcony, etc. and they all have some parameters. For the actual building I want variable list of parameters, like the point list in the add sop, so I can add/delete different floors with different properties. Is there a way to achieve this?

thanks

Not in Houdini 8. However, Houdini 9 now has multiparms. Create a folder and switch its mode to multiparm.

haven't checked out the multiparams yet but maybe some of it could be done with copy-stamping and custom point attributes?