Vastu shastra (vasthu shastra) means science of architecture and construction. Found in Indian subcontinent, these survive as manuals on design, layout, measurements, ground preparation, space arrangement, spatial geometry and other aspects of architecture. Vastu sastras incorporate traditional Hindu and in some cases Buddhist beliefs. The designs are based on integrating architecture with nature and ancient Indian beliefs utilizing perfect geometric patterns (yantra), symmetry and directional alignments. Ancient Vastu Sastras discuss design of Mandir (temples), and include chapters on the principles, design and layout of houses, towns, cities, gardens, roads, water works, shops and other public necessities.While most Vastu shastras describe rules of construction and architecture, a few include chapters on astrology and rituals recommended for buildings. There are many principles in Vaastu Shastra. To mention a few which involve certain mathematical calculations, Maana is used for proportional relationships in a building and Aayaadi specifies conditions for maximum well being and benefits for the residents of a building. In Indian architecture, the dwelling is itself a shrine. A home is called Manushyalaya, literally, "Human Temple". It is not merely a shelter for human beings in which to rest and eat. The concept behind house design is the same as for temple design, so sacred and spiritual are the two spaces.