Compass School of Feng Shui is concerned with how the building or apartment is engaging with the environment from the perspective of Gua Qi (卦氣). With this, there are some Master advocating the 3 realms (三才): Heaven Qi is to face (向), Earth Qi is to ride (乘) and Human Qi is to take in (納); creating confusion to the learners.
By removing the this 3 realms (三才) analysis, essentially there is only sitting and facing. Therefore, when dealing with sitting the practitioner aims for riding the Qi flow. And, when it comes to facing the practitioner is concern with taking in the Qi.
• To “ride” (坐/乘氣)
• To “face” (向/納氣)
The 8 Mansion Method (八宅明鏡) typically uses sitting to determine Fu Wei, and to calculate the locations of the eight wandering Qi through Yao line changes.
The Flying Stars (玄空飛星) tends to use the facing direction to calculate the location of the flying stars.
While in the theory of Yang House 3 Needs (陽宅三要) would use the front door as its Fu Wei (付位), to calculate the locations of the eight wandering Qi. This method is extremely useful for those property which need to install front and back doors.
Lastly in Xuan Kong Da Gua (玄空大卦), it embraces both facing and sitting (which aims at both riding and facing); in the aspect of Sitting, Mountain, Facing and Water (龍山向水) and aims at creating certain combination of formula to match the house with the residents.
“formulas without forms is the equivalent of drinking soup with a fork”