How do we choose a direction when no planet in the chart is exalted and several planets sit in one direction?
First choose the direction of exalted planets. If none are exalted, go towards the direction where the benefic planets sit: Venus, Mercury, Moon and Jupiter are benefic, while Rahu, Ketu, Saturn, Sun and Mars are malefic. Then use the interior items, seed mantras, artifacts, statues, trees, colours and symbols, to strengthen the planets that are not exalted.
Related questions
Apart from gridding the house, should the kitchen be gridded separately?
Yes. Interior vastu means zoning each room separately with its own grid and then designing its interior accordingly.
As an interior designer, clients choose their own colours and I cannot check their planets; should I give a remedy or try to convince them?
Do not try to convince anyone. People mostly like the colours that match their own planets. If a client chooses an anti-element colour and their kundli allows it, never stop them; it will bring them benefit.
Can these planet artifacts be used even when the birth chart shows no defect?
Yes. Without a dosh they simply add energy. Nobody would refuse if God offered an exalted Jupiter, Mars or Saturn in their chart, and decorating with the items that represent such planets raises energy in the same way. Energy never becomes so much that it causes harm; how the gain is used is the person's own responsibility.
Do the directions of the kundli houses shift when the rashis or planets in them change?
No. The 4th house is always North, the 1st East, the 10th South and the 7th West, with the sub-directions between them. Like water flowing in a river, planets and rashis keep moving, but the direction a house represents stays fixed whichever planet or rashi comes into it.
Each house of the kundli has a rashi in it. Does the rashi decide the direction?
No, the rashi plays no role here. The 4th house is North, the 1st house East, the 10th house South and the 7th house West, with the sub-directions in between. Real charts are then analysed, five a day from the student group, to decide each person's interior; the key is knowing what to do for exalted planets and what for debilitated ones.
For someone with no astrology background, what does an exalted or debilitated planet mean in practice?
Learn the twelve rashis in order and the rest is simple. If the Sun is written with rashi 1, it is exalted, very powerful, and blesses the house and direction it occupies. If the Sun sits with rashi 7, it is debilitated and very weak; if that falls in the 4th house (North), building a house in that direction ruins the person. Vastu without this is incomplete, which is why even a perfect East-facing house can fail.