In small buildings, don't cluster all the rooms together around each other; instead string out the rooms one after another, so that distance between each room is as great as it can be. You can do this horizontally - so that the plan becomes a thin, long rectangle; or you can do it vertically - so that the building becomes a tall narrow tower. In either case, the building can be surprisingly narrow and still work - 8, 10, and 12 feet are all quite possible.
House for One Person --> HERE HERE --> Light on Two Sides HERE --> Flow Through Rooms
The feeling of overcrowding is largely created by the mean point-to-point distances inside a building. In a small house these distances are small - as a result it is not possible to walk far inside the house nor to get away from annoying disturbances; and it is hard to get away from noise sources, even when they are in other rooms.
To reduce this effect the building should have a shape for which the mean point-to-point distance is high. (For any given shape, we may compute the mean or average distance between two randomly chosen points within the shape). The mean point-to-point distance is low in compact shapes like circles and squares, and high in those distended shapes like long thin rectangles, and branched shapes, and tall narrow towers. These shapes increase the separation between places inside the building and therefore increase the relative privacy which people are able to get within a given area.
Try Lineup Viewer