The North-East is the most sacred direction, so why should the main door not be opened at E1, the pada of Shikhi devta?
Because it is the most sacred and pure place, entering there with shoes and slippers is a serious problem. Shikhi devta, who sits at E1, then produces his fire, and his anger brings agni bhay (fear of fire), a greater chance of fire breaking out in the house. So E1 should not be used for the main door, even though people commonly praise it.
Related questions
The house door falls on Parjanya (E2) and the family has more girls; why, and what can be done?
A door at Parjanya makes the house female dominated: females are more in number, more female calves are born and the first child is often a daughter, though this also depends on the fifth house of the horoscope. The remedy is to make the Om and swastik symbol taught for Shikhi at that door.
Why should a house door, kitchen or toilet not be built at Shikhi (E1), and which doors are allowed there?
Shikhi sits there and the spot holds heat and fire, so a house door at E1 can cause fire incidents and accidents. A boundary-wall gate is allowed, being in the pishach bhoomi, and so is the door of a temple or other religious building, a school or a college, because such buildings represent Jupiter and become the yogi's own home. A kitchen at Shikhi keeps health poor and brings memory loss, money problems, anger, indecision and a blocked mind, and a toilet there in the North-East stops vansh vriddhi (growth of the family line).
Can doors be opened anywhere by vastu, or must the birth chart be checked?
Check the birth chart. If the Sun in the chart is debilitated and you forcibly open an E3 or E4 door, it will be wrong and not appropriate at all.
Does the coconut kalash for Parjanya work when kept outside a door at E2?
Yes. In a flat seen on a recent visit, whose door is exactly at E2 (Parjanya), the resident keeps a water-filled kalash with a coconut on it outside the door and changes the water daily; the coconut has grown into a large plant, and the resident reported very good results for ten years without needing any planetary remedies. This is exactly the remedy prescribed for Parjanya.
How do we find N1 to N8 and the other door padas on a map?
Use the zoning chakra shown on the first day, or draw it: from the centre of the map draw the four directions 90 degrees apart and the corner directions at 45 degrees, then halve again to 22.5 degrees and once more to 11.25 degrees, which gives 32 padas (360 degrees shared by the 32 guardian devtas). Starting from E1 next to the North-East line, go round clockwise from E1 to E8, then S1 to S8, W1 to W8 and N1 to N8, on the 81-pada grid. Practise this as homework.
I learned elsewhere that in 81 pad vastu the East falls between E4 and E5. Is that right?
No. In 81 pad vastu exact East falls on E5 (Surya); East between E4 and E5 belongs to the 64 pad grid, so correct it. The reference is in Vishwakarma Prakash, with the page number given in the previous class; the Hindi translation from Sanskrit by Krishna Kumar Jugnu of Udaipur and the edition of Maharshi Abhay Katyayan give the same.