Why is the North called the direction of wealth and of Kuber?
Because among the four Vedas the North represents the Atharvaveda, linked with artha (wealth), and its lord is Kuber, the controller of wealth, career and opportunity.
Related questions
A relative's flat had its door at E1. After buying the adjoining flat and removing the common wall the entrance came onto N4, and soon their ancestral land was acquired for a bullet-train project and they received crores. Is this the N4 effect?
Yes, this is chhappar phaad wealth, which comes as soon as N4 opens. E3, N4 and W4 are the three vipul sampada dwar (abundant-wealth doors). Opening them virtually gives perhaps 1 percent of the actual result, so do not believe the heavy promotion of virtual doors; it is the actual opening that brings the result.
At what time does the West direction show its greatest energy?
After sunset. Its power is felt from sandhya kaal onward and increases as the night advances, which is why people do sadhana at night and worship Lakshmi at night for wealth.
Does the tijori zone also apply inside a room, and which way should the tijori face?
Keep the tijori in the zone given for it and make it face North. A room in the SW, say 12 by 15 feet, is entirely SW, not only its corner; it has four walls, so keep the tijori against the South wall and it will face North.
If the North of a flat or house is polluted, for example by a toilet, should we advise removing it, and is a pooja needed afterwards?
Yes, advise removing it: the North is Kuber's place, and keeping filth at the place of wealth is like putting dirt in the mouth, so wealth cannot grow. After any demolition do a Vastu pooja; even a short one is enough, offering 45 small pieces of gud to the 45 devtas or invoking the nine lords with Bho Indra Vastu Dev Vastu Shanti Kuru Kuru and so on for each direction, with Brahma at the centre.
My main door covers N8 and E1. However much money comes in, loans keep running, one ending as the next begins. Is this the poverty effect of the door?
Yes. N8 is the door of poverty (nirdhanta): a shortage of money persists and one keeps borrowing from others and from banks. The North-East corner padas around N8 and E1 are the doors that make a person poor, which is why the main door should not be in the Ishaan corner. Close it if that is at all possible.
The kundli chart was shown with directions. How are those directions used, and what can a kundli tell about a house?
Go by the houses, not the numbers written in them: the top house is the 1st house (East) and the 4th house is North. If the planets on the North side are strong, the North direction is very good for the person. A kundli can even reveal where a person's house is, where its door is, how many windows it has and where a nearby river, pond or temple lies, so a map of the house can be drawn without seeing it.