The exterior appearance of Hogwarts castle has a unique and easily recognisable look. This article is about the incredible detailed model of the castel, that has been used for every film in the series.
While most of it stays the same over the series, there are changes between the movies. Most obvious are the changes between the second and the third movie (a bell tower, a bridge, and more is added). These changes can (maybe) be rationalised by the explanation that in the first parts no scene is taking place near the areas added in later parts.
Is it theoretically possible, that Hogwarts Castle never changed it's exterior appearance during the movie series?
I'm not asking about behind the scenes material, as I'm sure they have made changes there. I'm wondering about the audiences point of view. Example: Throughout the series we see Hogwarts from a lot of different angles. Let's say in part 4 a new tower appears. The absence of this tower in older movies can be explained by it beeing hidden behind a wall. In this case there was no "real" change. The tower could have existed before, we've just never had a chance to see it.