The Pa Kua can be used for any shape of a home or room as long as it remains proportionately the same. When you have extensions or missing areas you need to consider how happy you are with the aspect of your life missing from the Pa Kua. If you are not satisfied consider placing cures to include the missing area and concentrate on the other areas of your home which relate to that issue.
If your home include the yard you can look at ways of building something in the yard to make a visual link between the missing space and your home. If circumstances allow it you may consider an extension or conservatory. Other options that are also more than satisfactory include placing an outside lamp, a large water feature, raised planting beds with large colorful plants or a tree that at the point marks the corner of the missing section. If you do not have a yard the appropriate cures include using large mirrors in the areas next to the missing section in order to suggest expansion and provide an illusion of completion period five-element cures or also important here in order to enhance missing elements you would have had, where the Pa Kua are represented completely.
One method for replacing a missing area and enjoying its associated luck is to illuminate the corresponding area of the yard. As you do that you will be completing that section of the Pa Kua.