Reveal, you told him, you didn't show him.
The first thing is, who said he had to have a home up there. He doesn't want to live there, all he wants to do is summon on owl. And since anybody can visit, there should be no problem in simply going there and casting the spell.
Groundskeeper: Excuse me sir, but what are you doing?
Ranger: I'm summoning an animal companion.
GK: What sort of companion, sir?
Ranger: An owl.
GK: Any particular type of owl sir?
Ranger, An ordinary owl, nothing special.
GK: Carry on then, sir. I'll make sure you are not disturbed in your summoning.
The first thing is, who said he had to have a home up there. He doesn't want to live there, all he wants to do is summon on owl. And since anybody can visit, there should be no problem in simply going there and casting the spell.
Groundskeeper: Excuse me sir, but what are you doing?
Ranger: I'm summoning an animal companion.
GK: What sort of companion, sir?
Ranger: An owl.
GK: Any particular type of owl sir?
Ranger, An ordinary owl, nothing special.
GK: Carry on then, sir. I'll make sure you are not disturbed in your summoning.