Shrieking shack

[sophiamcl]

I just posted, but forgot to mention something. As you are all 
probably aware, a slew of pictures from PoA has recently surfaced. 
(for instance at http://www.hpana.com)
Among them are a picture from the Shrieking Shack set. It looks great-
-like the interior of a fancy villa that has become delapidated. 
However, this look to me is uncanonical. I thought the house was 
built specifically for Remus arrival to Hogwarts, which would mean 
there's no other story to it than that Remus used to transform there--
no need for fancy furnishings, like a grand piano... On the other 
hand, I may be wrong, maybe Howgarts just bought an existing house 
for the purpose--does anyone know the answer? (Lent my copy of PoA to 
a neighbor, so can't check it.)