The Sideyard, like the Thin House, must be at least twice as deep as it is wide. But the Sideyard must also orient most if not all of its openings to one side or the other, leaving the other side mostly blank so as to preserve privacy in its neighbor’s side yard.
Windows are OK, if they’re high on the wall or obscured. The Charleston Single House was the original Sideyard house type. In Charleston, not invading your the privacy of your neighbor’s garden is known as “North Side Manners” because the gardens were always on the south side of the houses so they would be used. Nobody crosses the long band of shadow found on the north side to go outside, even if they’re going out to sit in the shade. The important thing with the Sideyard House is to turn the side yard into inhabitable outdoor rooms.