If you want "crease edges"
Separate the faces wanted!
Select all - Subdivide - disable Keep corners !


Accept also the "open faces"


If your volume don't want subdivide ! Subdivide the problematic faces before!


You can take only some faces but "Join" them before subdivide! (Shell if wanted! ;)








All renders with the funny Real Time very easy free SimlabComposer Lite (Maxi 1920 *1080)