The selection of site for building construction is very important in vastu elements. Besides, congenial environment, greenery and availability of water, we should also see if the land is suitable for building construction.
As far as the flow of domestic water is concerned, it should be borne in mind and that such water should be drained out in North - East. Wells, tubewells, swimming pools etc. should all be in the North-East. The water from the toilets and bathrooms, too, should be drained out in the North-East. The North-East direction is always auspicious and suitable for water. There are sewer-systems in the cities. The Septic tanks or the flow of sewer systems should be towards North - West. The flow of rain or fresh water should be towards North - East as per vastu elements.
The direction of Fire is South-East. The Kitchen, fireplace, geysers etc. should be placed only in this direction. Alternatively these could be placed in North-West, because it is at 180 degree to South-East.
The air should enter the building from North -East. All the openings and media for air entry such as doors, windows, ventilators coolers, air-conditioners, verandahs, balconies etc. should be in these directions.
The open sky influences greatly. We can get the effect of terrestrial-energies uninterruptedly. But the buildings prove a barrier to the effects of open sky. Therefore, the importance of roofs or lawns gets emphasized, but the Vastu shastra has refrained from deliberating in detail over it, because it is related chiefly to building construction. Traditionally every house in India used to have an open space (CourtYard) in the center of the house. It provided the dwellers not only the open sky but also sunlight and cross-ventilation of air.