First of all home feng shui and religion is unrelated. So not having an altar at home does not mean that your home is bad feng shui.
Altar placement based on feng shui principles is of paramount importance because it is like inviting a “VIP” to reside in your house. For those with who are having a religion it is a form of respect to place your deity in the most honored sector & not the “leftover” space after putting your TV, sofa etc. Therefore if you intend to place your altar, your other living hall furniture becomes secondary. All the rest of home decor items have to accomodate the position of your altar.
Here is the elementary version of “do’s and don’ts” for altar placement:
1. Place it in the Living Hall unless you have a private room to spare solely for worship purposes.
2. Install your altar within the “Home Destiny Lucky Energy sector 藏风聚气的吉方”.To quote from 易經 iChing, positive energy is created when it is “activated or in motion 吉凶悔吝者, 生乎動者也”. So if unfortunately your house is limited in space or the entire living hall is within a “negative energy” zone e.g. critical illness area, then you are better off visiting the temple or church for worship.
3. The minimum height of your God sitting position must be above your shoulder. Take for instance if you your floor to ceiling height is 3 metre than your God sitting position should be 2 metre & above. One can divide your house into 地 from floor 1 metre 人 middle and 天 2 metre onwards. The principle is extracted from: 周易三才 中指“天地人”，三才之道即天道、地道、人道，立天之道曰阴与阳，立地之道日柔与刚，立人之道日仁与义.
4. Faces towards the Main Door or Window i.e. open area. If given a choice for both directions, one can redefine it by facing towards an auspicious 生旺方 direction. In period 8 is either “8” “9” or “1”.
5. Ensure that your altar is 稳 定 靠 supported by a solid wall, peaceful and it is stable
6. Place it within the House quiet location 安静 away from television, audio, electrical equipment 声杀 or router 磁电煞
7. Size of the Altar proportional to your house. Big house big altar.
8. Keep the Altar clean and bright.
9. Choose an auspicious date to “commence” the God worship e.g. shift in dates given by your feng shui master.
1. Have a fish tank above (淋头水), below (割腳水) or beside the altar. i have seen some decorations where the God is inside the koi pond, that is really bad.
2. Place it at passage way 通道-动线 e.g. corridor, walkway of the house, because worshiping God is supposed to be in a tranquil place.
3. Place it beside the Main Door (动方) or any bedroom door (人位) or any “entrance/opening” e.g. kitchen opening
4. Have any rubbish beside or under or inside the altar, it pollutes your God.
5. Suspend your Altar in mid-air, it is unrestful for your God.
6. Place it facing the toilet door 孤陰 or bedroom door or kitchen 燥陽 opening.
7. Worship to many Gods and it becomes overly crowded. Some clients mixed different religion together which in my opinion is disrespectful.
8. Place it directly opposite (180 degree) a mirror.
9. Place it at the wall where behind is the toilet (污水) or kitchen (燥火) or staircase/walkway.
10. Put it under an overhead beam 横梁. Beam that is adjoining to the edge of wall is not overhead beam.
If one can place the altar fulfilling all the conditions above, chances are you have position your altar correctly.