It was about thirty foot away from the house, maybe, and I sort of got it into my head that, if I climbed up that tree, I'd very likely be able to see into that room.
The room had windows so that I could see inside.  
mnli hypothesis: The room had windows so that I could see inside.   premise: It was about thirty foot away from the house, maybe, and I sort of got it into my head that, if I climbed up that tree, I'd very likely be able to see into that room.