I think this is the front of the house, not the back. The drive comes across the grounds, rather than round the end of the house, and I doubt the back of a house would have an ornamental fence like that.
I appreciate that some of the house looks rather plain, but if you look closely, you'll see that the window tracery at the left hand end is different from that at the plainer right hand end, which indicates that it wasn't all built at the same time. The line of the windows also indicates that the rooms will have progressively higher ceilings going from right to left.
I suspect that the oldest part of the house is to the right, then it's been gradually extended towards the left, possibly in 4 or more stages. Finally, as the owner got richer or wanted to make more of a statement, the left hand end was built with its bay windows.