Vastu recommends regular shapes which are balanced and symmetrical. As a general rule square and rectangular plots which have all the angles at 900 are considered appropriate.
Plots in which all the aides are equal and at an angle of 900 are considered the most auspicious. Vastu Purush fits best in a square plot and all his body parts are in good shape leading to all round prosperity and health.
Plots in which the opposite sides are equal and all angles are of 900 are considered very auspicious. The ideal proportion of length and breadth is 1:2. Very narrow rectangular plots are not considered auspicious as they make one feet like living in a long corridor.
Circular plots are auspicious for residential and commercial purposes provided the construction is also circular. In case the construction inside a circular plot is square or rectangular. It gives bad results. According to modem scholars, circular plots and circular construction is inauspicious, especially for residential purposes. Although we do find examples of circular Vastu like stadiums, Parliament House, minarets, Buddhist stupas, Ashoka Pillars etc. which are of architectural, historical, monumental and religious importance scattered throughout India.
Plots which are triangular in shape are considered inauspicious as they give negative energy. As for as possible, avoid purchasing a triangular site. They lead to Mental tension, defame, disputes and losses. In case you own a triangular site, it is important to rectify it such that it becomes a square or rectangular site.
Such plots are unfit for residential purposes but good for religious Vastu.
Cow-Facet / Gou-mukhi Plot
Plots which are narrow in front and broad at back are called Gou-mukhi plots and are good for residential purposes. Gou-mukhi plots are inauspicious for commercial purposes.
Lion Facet / Sher-Mukhi Plot
Plots which are broad in front and narrow at back are called Sher-mukhi plot. These plots are auspicious for commercial purposes but are inauspicious for residential purposes.
Six-sided plot with all six sides equal is called a Hexagonal plot. This type of plot is good for prosperity and growth.
All irregular shapes are considered inauspicious unanimously by all classical exponents of Vastu. These recommendations have proved to be astonishingly true even when tested by modern science and modern engineering principles. Square and Rectangular buildings score over other shapes when evaluated on various parameters like their load bearing capacity, load transfer capacity, cost of construction and space utilization within the structures is considered.
The capacity of the structure to withstand destructive powers of natural calamities like earthquakes, cyclones and other natural phenomenon depends on the suitability and strength of soil. The supreme wisdom of our sages translates into concern for suitable sub-soil conditions, proper laying of foundation and construction in regular shapes.
While we may not be able to prevent earthquakes but their impact on structures can be reduced by using right materials and balanced vastu designs wherein all elements are in harmony and interwoven to form a cosmic shield around the structure.
The square is the fundamental, essential and perfect form of Indian architecture. In a square, the panchamhabhootas are said to be in perfect balance. So a square or building of square shape, and to some extent, rectangular i.e. where length and width is in 1:2 proportion has always been considered stiff and firm, congenial and compact. It becomes stable when placed on ground and cannot be displaced or destroyed easily. It is not affected adversely by vibrations and offers a large counter force against seismic forces. Irregular shapes resulting uneven distribution of forces thereby leading buildings to collapse. It should be remembered that earthquakes themselves do not kill people, but badly constructed buildings do. In case, you own a site which is of an irregular shape, please consult a competent Vastu practitioner to rectify the site in a way so that positive results can be generated.