Re: "a window in the house next" or "a window at the adjacent house"
I don't quite understand your question, but here's my take:
When you walked down the path you passed a window in the house next door and you tried to look ahead of you to avoid looking through the window and seeing what was going on.
In AmE, it would be more natural to say "When you walked down the path, you passed the house next door and you tried to avoid looking through the [picture] window and seeing what was going on."
"Picture" in this case is optional and/or implied; in many suburban houses, there is a large window on the front facade of the house facing the street or sidewalk; this is referred to as a "picture window."