The Eight Mansions method of Feng Shui is part of the San Yuan school. It is one of the simplest and easiest to master methods of classical Feng Shui. Eight Mansions is known in Chinese as Ba Zhai (literally, "Eight Houses"). It is one of the oldest internal Feng Shui methods.
The Eight Mansions system provides a long-term, stable approach to classical Feng Shui. This is in contrast to the Flying Stars Feng Shui system, which is more dynamic and thus requires perpetual changes. Because of this stability, the Eight Mansions system is well-suited for house planning and building layout purposes.
The basic idea behind Eight Mansions Feng Shui is that every house can be classified into one of eight types. The goal is to match the resident(s) to the most suitable residence.
Note: Eight Mansions is an internal Feng Shui method, and is thus not suitable for assessing landforms.
Reference sources for the Eight Mansions system include classics like Eight Mansions Guiding Mirror (Ba Zhai Ming Jing), Yang House Three Essentials (Yang Zhai San Yau), Golden Star Classics (Jin Guang Dou Lin Jing), and Yellow Emperor House Classics (Huang Di Zhai Jing).
The Eight Mansions system uses the Life Gua and the House Gua in its application. The Life Gua is used to categorize the residents into groups based on their personal Gua (Trigrams). The House Gua classifies houses into groups based on the house's Gua.
The Eight Mansions system refers to eight different types of Qi, known as the Eight Wandering Stars.
At more advanced levels, Eight Mansions uses a method called Star and Palace Relationship (Xing Gong Sheng Ke), which uses the Five Phases to analyze the interaction between the Wandering Stars and the Palaces they occupy. Other advanced methods include Greater Wandering Years (Da You Nian) and Lesser Wandering Years (Xiao You Nian).
Always remember that forms override formulas. Thus, negative external forms can have negative impacts upon the Wandering Stars in a particular sector. The outcomes of the affliction will depend upon the Star being afflicted.