What it does
To zone a house before it is built.
Any land, plot, flat or large project, whatever its carpet area, is divided into four concentric parts: the outer pishach bhoomi (pishach veethi), then the manushya bhoomi, then the dev bhoomi, and the brahm bhoomi at the centre. Each part has its own nature and decides what may be built or kept there.
The outermost band of a plot, the pishach bhoomi, is the seat of the 32 lokpals and bears the noise of the road. It is where the boundary wall and its gate, servant quarters, guards and pets belong, where flags are hoisted and where shilanyas (foundation stone laying) is done.
Nothing valuable or sacred should sit on the pishach bhoomi: never a tijori, court case or other important papers, a child's study table, a bed set directly against the wall, or a deity and home temple. Leaving even a 2 to 3 inch gap from the wall keeps an item off the pishach band.
On plots of up to about 1000 sq ft (60 to 90 gaj), simply building the wall on the outer band ends the pishach dosh, because the pishach devtas are content with a little space. On plots of up to about 1500 sq ft, leaving the pishach portion open or walling it also satisfies them.
Each of the 32 devtas of the outer band has its own tree. Planting that tree at the devta's place, on the pishach bhoomi or along the boundary wall, makes the lokpal stable; it connects with cosmic energy and feeds energy to the pishach, manushya, dev and brahm bhoomi.
The manushya bhoomi, the second band inward, takes the main door, windows, kitchen, bedrooms, dining room, puja room and stairs. No shilanyas, boring or pit should be made in it, and above all not at the corners of its transition with the pishach bhoomi, where the shishu pishach and pishacha points lie.
The dev bhoomi, the third band inward, can take everything the household needs, from the main door, windows and kitchen to bedrooms, dining, puja room and stairs. It is the best place for the puja room, the safe, a study room, a meditation room and all important documents, because this land is covered with divine qualities and makes work succeed.
The brahm bhoomi at the centre suits a courtyard (aangan), tulsi worship, an area open to the sky, a living area and a place for yoga or meditation.