Feng Shui of HDB Punggol Opal and the Flying Star Feng Shui of 4 bedroom type:- 1. This development has only two stacks that are E2 facing: stacks 637 and 639. E2 facing stacks: It is such a waste that the combined auspicious wealth stars are wasted at the "rear" of the house. This is usually where the kitchen and yard are. 2. The remainder of the stacks are either N3 or S3 facing. Under Flying stars; there is a difference between a N3 facing vs a S2 facing chart. 2.1 Here, under N3 facing;