According to vastu shastra all of floor apply influence. The internal parts of flat should be constructed according to vastu. The upper floors are less noisy since the inmates spend more time together as a family in the living room, dining room and kitchen. The energy in the upper floors should be restful and comforting. The balconies in the upper floors should be in the north, east or north-east.
Avoid bedrooms above the car porch and kitchen. The scientific reason is fumes from the kitchen and the car exhaust that rise up, can be a nuisance and not good for the health of the inmates of the bedroom. And avoid bathrooms above the bedrooms. Placing the kitchen above or below a toilet or bedroom is one of the most severe vastu defects.
Also the prayer room should not be above the kitchen sink or stove as it brings had luck and drains wealth. Normally north and east direction are considered as best directions. North facing entrance gives prosperity while east facing gives fame. Land slope towards north-east. increases knowledge, all-round prosperity, and health. Elevation in south and west are desirable.