In comparison to landed property, selection of a apartment unit with good feng shui is so much more important. This is because there is very little you can do to remedy any feng shui flaws inherent after you bought the house. These are the difficulties for apartment dwellers:
1. When the kitchen is in a bad sector, you can't relocate it. The possible positions for the stove is also highly limited.
2. When there is a missing corner, you can't fix it but for a landed property, you can build a n external wall to compensate for the missing sector.
3. If the bad flying stars are all in the important parts of the house, you can do a major renovation (including the roof) and possibly change the period of your house if it is landed property but for apartments, there's no way you can do this as your unit is only a small part of the whole building. Renovating your apartment alone will not change the period.
4. When the apartment's main entrance opens to a inauspicious direction, you do not have the luxury of using an alternative entrance (unless you are Superman). You also can't relocate the main entrance since the developer (e.g. HDB) have restrictions on this.
5. Many apartment's bedroom now are designed with only one possible bed position. So you can't do much if it is your bad sleeping direction.
6. You have no control of where the toilets are located in an apartment unless you are the developer. Too bad if your wealth stars end up in the toilet.
In conclusion, for those intending to purchase a flat / apartment, consulting a Feng Shui practitioner during your house hunting is far more important then after you have bought the house.