@Heaven_s_Thunder_Ham, fair interpratation.
Do you hold the same in regards to requisites for instant transportation spells?
Humm. This is both RAW and weird. Clearly the rule was written by someone who never thought a Room could be able to cast a spell.
I might be misremembering (away from my books), but I seem to recall that the aforementioned effect (Convenient Storehouse, from MoH) uses R:Personal.
Anyway, seems like a nice place for a houserule.