Orientation and proportion in Indian traditional domestic architecture

From ancient times, the traditional architectural practice ‘Vastusastra’ is rigidly followed and practised in many parts of the Indian sub-continent and has a unique position in Indian architecture. In Indian traditional domestic architecture, a hand calculator table and an index number system are used for finding the proportion and orientation of the building. The mathematical and logical background of this traditional practice, which is not known at present, is investigated in this paper. The study reveals that there is a strong and complex mathematical background behind this traditional architectural practice.