The Burrow burnt; the Burrow rebuilt

So I'm watching the last three Harry Potter films... just because. I don't particularly like them but, once in a while, I feel the need to see them again. Especially when I am re-reading the novels.

As I read The Half-Blood Prince (in French), I thought I'd throw in the Blu Ray of the movie version, which led to where I am now, with The Deathly Hallows, Part I, in the Blu Ray player, watching the opening scenes.

And it occurs to me, as it has several times before, to ask the question: if the film-makers decided to take the creative liberty in the sixth movie of introducing an all new scene in which Bellatrix, Greyback and several other Death Eaters attack and finally burn the Burrow to the ground, why is that particular domicile back at the start of the seventh film, rebuilt exactly as it was?

The Burrow was always, in novels and films, a ramshackle collection of rooms, pieced together over years and years, making no sense, comfortable almost in spite of itself. In the books, it never burned so there was no reason for Mr. and Mrs. Weasley to rebuild it into a more practical, more comfortable structure.

In the film, however, we see the Burrow completely engulfed in flames and we get a close up of Molly Weasley, standing by, helpless, as it burns to ashes.

By the time the seventh film starts, however, the Burrow is back in one piece. Exactly the same ramshackle, ill-designed piece that burned only a few months before. Why not improve it? Why not make it a more sturdy structure, bigger, better designed,with better flow, better light, better everything?

Sure, you can tell me that the Weasley's made the decision to rebuild the Burrow exactly as it was before out of a sense of history, of sentiment, of not wanting to lose their "home". But it makes no sense to me.

Is it possible the film-makers simply forgot that they burned it to the ground????