It's good to see you're trying something new instead of recoloring the same house over and over again.
IMO, the height and length of the mansion isn't very proportional to the backyard, it just overall seems very unbalanced and flat and compact. It's kinda awkward. I feel as if this could have used more preplanning and some measurements.
Other than that, the brickwork is very nice and detailed (albeit somewhat repetitive), and it looks pretty great overall.