I have received a lot of inquiries from Australia, New Zealand, Brazil , Argentina, Venezuela, South Africa, Singapore and Malaysia. The simple question is,
"Can we practice the art of feng shui without modification
in the Southern Hemisphere and along the equator?"
The simple answer I gave out was,
"Yes. There is no need to modify the conventional technique
we employ in China. Feng Shui Principles and auditing
method remain the same in all parts of the world. Perhaps
there are two places on earth that we cannot practice this
art and these two places are the North Pole and the South
Pole. These are points of singularity (Wow, a sophisticated
mathematical term!). At the North Pole all directions are
South and at the South Pole all directions are the North.
My answer is based not on theory but practical data both by feedback from fellow practitioners and my own experience.
If we examine the fundamentals of Feng Shui, we will discover areas that cast doubt on the above experimentally based answer.
(1) The Five Elements
These need not be modified. Since they denote different forms of energy they will be the same even in other parts of the Universe.
However, we must know that the words we use to represent these energies are only the words that most satisfactorily display the behavior and character of these energies. Thus
Metal - Sharp, solitary.
Water - Liberal, spreading, nourishing.
Wood - Upwardly mobile, growing.
Fire - Radiant, hot, dissipating.
Earth - Stable, concentrating.
(2) Yin and Yang
This is a universal concept of contrasting qualities and it should not be modified.
There is a common mistake in classifying yin and yang. Some people think that mountain is strong while water is weak and thus mountain is yang and water is yin. This is not true. In Feng Shui, we emphasize on motion and stillness. Mountain is stationary while water is moving. What is stationary is yin while what is moving is yang. Therefore water should be considered yang while mountains yin when they are compared.
(3) The Ba Gua
Here I refer to King Wen's Hou Tian Ba Gua that is used in Feng Shui. This is commonly translated as "The Later Heaven Ba Gua". It is a word for word translation.
Xian = Early
Hou = Later
Tian = Heaven
but the terms "Hou Tian"and "Xian Tian" are compound terms made up of two characters and "Hou Tian" does not mean "Later Heaven".
"Xian Tian" means "Original", "Born with", "Occur naturally".
"Hou Tian" means "Later", "Acquired after birth", "Assimilated artificially"
The "Xian Tian Ba Gua" was supposed to have been discovered by Fu Xi . King Wen  modified it according to the Luo Shu and it became known as the "Hou Tian Ba Gua".
This is the center of controversy around the Southern Hemisphere issue if we consider the Ba Gua merely as an energy map.
Since the study of Feng Shui originated in China, a lot of the principles are referred to the geographical aspects in central China. It is natural to think that the Ba Gua was created with the climate in China as the basis. The heat energy mainly comes from the south and thus the Fire Palace of the Ba Gua is assigned to the south by King Wen. The eastern parts of China is more vegetated than the west where minerals may be more abundant. King Wen thus assigned the Thunder Palace to the east, Wind Palace to the south-east and these two palaces are both wood in nature. He further assigned the Marsh Palace to the west and the Heaven Palace to the north-west and these two palaces are both metal in nature. There is abundant storage of water in the form of ice in the north and it is not coincidental that the Water Palace is in the north. The remaining sectors, the north-east and south-west are assigned the Mountain Palace and Earth Palace respectively.
Now in most part of the Southern Hemisphere the heat energy mainly comes from the north while the south is the ice-clad Antarctica. Should we modify the Ba Gua?
Yes, if we consider the Ba Gua as the map of different energies from the eight directions : N, NE, E, SE, S, SW, W, NW. The fact is that it is not. The Ba Gua contains much more than that.
Before we discuss the Luo Shu, let us try to answer the question, "Should the Ba Gua be modified in different areas of the earth?"
The reason why we have four seasons is because of the altitude of the sun at different times of the year. A map may be designed to locate the different sources of energies. As we move towards the tropical area heat energy dominates throughout the year. If we move towards the north pole the water energy dominates. The same map is used but the strengths of the various energies vary. As we move to the Southern Hemisphere the situation is reversed. It is just natural to design the map in the following way.
For areas on and near the equator it is the fire energy that dominates. Fire energy comes from all directions in addition to the other energies. The fact that in the tropical areas diseases can spread more easily is because the fire energy strengthens the #2 and #5 evil stars. It is also a fact that the tropical areas are more productive because the fire energy also strengthens the #8 fortunate star. The map that describes the basic energies that come from the eight directions is actually changing with the latitude. If the Ba Gua is considered the map of energies caused by the climate of a localized area then each locality will have its own Ba Gua. There will be an infinite number of Ba Guas instead of only two, one for the north and one for the south. The Ba Gua, viewed this way, is not all that we consider in feng shui studies. In fact, it is quite minimal compared with the "Luo Shu" which is the real energy map with energies from all sources - solar, magnetic, cosmic, ....
(4) The Luo Shu
The Luo Shu is the location of the nine stars at different times. A lot of people think that they are the stars in the Dipper. This is not true. There are billions of stars in the Universe. Why do these stars and not the others  affect the feng shui of a place? Besides, the Dipper cannot be seen in a lot of areas in the southern hemisphere. Does it mean that Feng Shui cannot be applied there? Ancient Chinese were fond of using the names of these stars in astrology  and it was just natural that feng shui masters used these names as well. I would rather say that the nine numbers represent nine different kinds of energies that change with time. These energies exist in the Universe and can be mapped onto a confined area defined by the relative position of the mountain and water . For houses we define the energy map by the way the house is oriented and also by the time when the house is built .
The Luo Shu was said to have been discovered by the first Emperor of the Xia Dynasty on the back of a giant turtle in the River Luo. Could it be a diagram on a space ship that visited earth at that time? This is not impossible and in fact more credible than the story of the giant turtle. Since the formula embedded in the Luo Shu magic square deals with all energies, it does not need to be modified. North is north no matter where on earth you are except perhaps on the north and south poles. In fact, the earth is only a speck of dust in the universe.
The Luo Shu Magic Square
(5) What are the Effects of Modifying the Ba Gua?
If the Ba Gua is the superficial energy map of a place taking into consideration the strengths of the five elements in the eight directions then it needs be modified with the latitude of the place under discourse, the prevailing winds and other local climatic conditions.
The Luo Shu is the energy map of a confined area defined by the positions of the mountain and the water. If the confined area is a house then it is defined by the orientation and the year of completion of the house. It does not need to be modified.
Modifying the Ba Gua affects the kind of energy from each of the eight
directions. Since the Luo Shu is not modified the location of the stars
in each direction is not changed. When we study the feng shui of a house
it is the facing stars and the mountain stars that play the most
important role. The facing star is responsible for the wealth while the
mountain star for the health of the people in the house. The time base
star is the basic energy in that location.
The basic nature of a particular corner in a house can be compatible or incompatible with the stars. This affects the capability of the stars in that area. Houses with the same star chart may differ according to the location. It does not need to go down under to feel the difference
(6) The Eight House School
This school of feng shui uses what are known as the "Eight Wandering Stars":
Four Fortunate Stars : Sheng Chi (Energizing)
Tian Yi (Heavenly Doctor)
Yan Nian (Longevity)
Fu Wei (Stability)
Four Harmful Stars : Jue Ming (Death)
Wu Gui (Five Ghosts)
Liu Sha (Six Demons)
Huo Hai (Mishap)
The location of these stars is based on formulas relating the Xian Tian Ba Gua and the Luo Shu numbers. Since we do not modify the Xian Tian Ba Gua and the Luo Shu, it should not be modified.
Common sense tells us that there are some differences between the Northern and the Southern Hemispheres. Feng Shui is common sense and of course it is more than just common sense. In the Northern Hemisphere, we like to build houses on the southern slope of a mountain and say it has good feng shui in the sense that it receives good energy. Can we do the same in the Southern Hemisphere? In the Southern Hemisphere the prevailing winds and the ocean currents are different from those in the north. We know that wind and water are the two ingredients of Feng Shui. Why then do we say that Feng Shui theories used in the north can be applied without modification in the south? Is it not arrogance? The answer is simple: The principles are unchanged. What changes are the forms (environment), not the star charts.
We must accept that there are differences and modifications are necessary. It is true that the formulas are not changed. Those areas that need be changed are the actual forms that affect the stars. We must know what are, and what are not, to be changed and why.
Feng Shui masters who pass on the art of Feng Shui in the form of writings had no experience with places other than China (Central Nation). Our hypothesis that Feng Shui can be practiced with the same methods in all parts of the world with only slight changes in the strengths of the energies from various directions is only logical deduction. It needs to be verified by experiments.
For more arguments on the same subject please read
 Fu Xi was the legendary first Emperor (B.C. 3322?)
 King Wen was the founder of the Zhou Dynasty (B.C. 1143).
 Master Lai Bu Yi (Sung Dynasty) used the 28 constellations as well.
 The nine stars bear the same name as those used in Zi Wei Dou Shu supposedly founded by Chen Bo in early Sung Dynasty.
 The method is known as "Da Xuan Kong"
 Feng Shui Correspondence Course Advanced Level by Joseph Yu.
Reference books and articles :