The wing room cannot be higher than the main room, but it must be lower than the main room.
In the past, the main house and the wing were generally not connected together, because the roof connected together was difficult to deal with. Now the main house and the wing can be built together, but it is not an L-shaped conjoined structure.
If you are afraid of bad feng shui, you can have a wall in the middle.
The wing is a small house on the left and right sides of the main house. Partial houses are common in rural areas and villas. There are many stresses on partial houses in Feng Shui, so we must pay more attention to them.