Before beginning to build, I try out many options for how I might lay out the scene through sketching. Whether they are drawn on paper or on my iPad, the sketches help me prototype the house without using any power tools or lumber.  I love this part of the development phase.  Below are several sketches showing the evolution of some of the ideas.

These sketches helped me come up with the final design.

As you can see, I explored several options along the way—everything from a Diagon Alley/Hogsmeade line of shops with the Hogwarts Express at the end to turning the whole front yard into Dumbledore’s office.

For the last few years, Grace has joined in to the ideation effort, contributing her own sketch for the house.  Can you see the different magical features from Harry Potter’s world that she incorporated into the her drawing?