"a window in the house next" or "a window at the adjacent house"

Dear teachers,

Here is a sentence from an English lesson.

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 my opinion the second variant of the expression in question is more proper one.
a window in the house next door = a window at the adjacent house

As you see, here is a confirmation of my words.

Crossing happens when the close up of the window at Bernie's house pans away to…

Would you be kind enough to tell me your opinion concerning the matter in question?

Thank you for your efforts.

Regards,

V.

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."