In these blue sky sketches I originally thought of building a full size house that would be divided into themed rooms. The sketches below show a more scaled down approach to the shop. I wanted something that felt like Diagon Alley.
The color studies above are for a different approach to the building. Logistically speaking a small gothic cottage would be enough space to house the store. One of the obstacles with the earlier concepts is the size. A massive shop would cost a lot but also would be very difficult to fill with handmade art items. So the downsizing allowed for the art to populate the store thoroughly and allowed for the cost of the build to be lower and more attainable.
The sketches above are for some iconic elements that would be seen inside the cottage. The fireplace is inspired by the monstrous designs from Disney's The Haunted Mansion and would be present at both fireplaces inside. Hanging a above could be either a mirror or painting that changes or reveals some secret. The grandfather clock in the middle pulls from the mansion as well. On the end Madame Iris would be a custom built fortune teller machine. It would give out fortunes and on the rare occasion a coupon to the shop.
The layout of the shop would include a small half bath, closet for storage, checkout desk, entrance foyer, and two separate retail spots. The two spots would allow for different themes but also help give a sense that this could've been an actual cottage at one point.
Here is the final color option I decided on. I wanted something that could appear to be all one color in contrast to the interior lighting but also during the day have some differences in color.