One of the fun parts of writing fiction is the inexpensiveness of its interior design. I fit out rooms, houses, whole landscapes with no more expense than imagination, pen and ink.
Of course, the design should reveal an aspect of the character, world or atmosphere of a given scene, but it still leaves me lots of room to play.
Initially I had the London portal opening into a pantry. But really that was pretty inhospitable of the Jekyll family. Now, the portal opens into a large ground floor room with windows overlooking an English garden, window seats built in and comfortable club room furniture scattered around. There is a flagstone floor because I love the word flagstone as well as the sense of permanence such a floor conveys. The fireplace is fitted with a fake gas log and a mirror hangs above the mantel.