I thought before I continued with the characters that having a feel for the environment would help a lot. Although I've got an image in my head of a mansion in the woods, seeing it visually on page would be much better. These are a few quick sketches to do with the environment from the outside.
I used some images as reference looking at woods, and old Victorian mansion/houses as an idea for the map. These houses when researching look as if they could have many floors and be very big inside so would work well as a maze.