Windows are the ideal forms of ventilation. Keeping in mind the position of the doors the windows need to be constructed too. If the door is in the East the window should be in the West. Similarly, if the door is in the North a small window should be in the South. The South direction is the direction of entertainment. If the door is in the East - North - East, the window should be in the West - North - West. Similarly, if the door is the North-North-East a small window should be in the South - South-East. The directions of the doors and windows can be easily interchanged.

The following units in a flat have a definite direction where the windows must be constructed.
I. The drawing room should have windows in the North and East.

II. The study room should have a window in the East.

III.The kitchen should have a large window in the East. The sun rays entering the kitchen is beneficial. The exhaust fan should be placed in the East or the South - South-East corner.

IV.Bedrooms should have windows in the West or North-West. Windows in the South need to be avoided and even if they are, they should be small and few in number.