How to make my floor to "HOST" the chairs (see attached)?

[bim3d]

I have a "dished" floor, created as an In-place-sweep. When I try the "Pick Host" command to make it the "host" of my chairs, the floor appears as "none pick-able". It seems that Revit only allow me to pick a regular floor to be a host, but not the "In-place kind.

How can I make my floating chairs "grounded"? Notice that my Floor is slopped radially. Any suggestion is greatly appreciated.

[Mr Spot]

I believe if you change the category of you chairs to a site based family and set the appropriate options in family category and parameters (can't remember exactly what they off hand) and reload your chairs they will be able to host to the floor.

HTH.