Perhaps this has been discussed before, but anyway: is merely the image of a room or a structure (think Creo Imaginem spell) sufficient to cast a spell with T: Room or T: Structure, respectively, that affects those within? (or T: Road, come to think of it).
For example, Magus Macrono, is accosted by some bandits. He has a Creo Imaginem spell that creates a very good image of a castle (for all 5 senses), including interiors, working fireplace, etc, and he has a ReMe spell that targets those people inside a structure to make them lose consciousness, an InMe spell to detect minds in a structure...a bunch of such spells (lets say he has Restrictions on Targets to justify this, or Special Circumstances, or a focus somewhere, or xyz). After hastily casting his "Wizard's Humble Abode" spell (and creating breathing space for himself!), can he then proceed with the rest of his T: Room or T: Structure suite more leisurely, taking the illusory castle's interiors as completely above board boundaries for Hermetic magic?
That question is tricky! My first thought was to say no, because when you create the image of something you don't actually create that something, in the sense that you couldn't poke a hole in that imaginem castle with a PeTe spell (nor affect the perfectly created image of a guy with Corpus magic). But then I realized it's just not the same to affect the image, targeting it with another spell, than to use that spell to make the target parameter of another one work.
Then the problem becomes equivalent to create a circle with Im to use it as a base for a D:Ring or T:Circle spell, and the corebook allows that:
So I'd say yes. I wouldn't even require the illusion to have 5 senses to allow that, I'd say vision would be just enough (actually pretty much required to identify the ilusion as the target for the following spells), and it would be recomended to add the touch sense if only because if your bandits figure that they can cross the castle walls after trying to touch one they will probably run out of your next spell's reach quite soon.