Water supply in a building is one of the most essential components of building design and maintenance, as it ensures the availability of clean and adequate water for various domestic, commercial, and industrial purposes. Proper water supply systems are critical not only for the comfort and convenience of occupants but also for hygiene, sanitation, fire safety, and overall building functionality. The planning and implementation of water supply systems in buildings involve a combination of civil, mechanical, and sometimes electrical engineering considerations to ensure efficient delivery and conservation of water. A building’s water supply system typically begins with the source of water, which may be a municipal water supply, borewell, river, lake, or rainwater harvesting system. The quality and quantity of water at the source must meet the required standards for potable use. Municipal water supply is commonly treated and provided at a standard pressure, whereas borewell or other sources often require additional filtration and pumping arrangements to make the water suitable for use within the building. The selection of the source also depends on availability, cost, reliability, and sustainability of the water supply in the region. Once the source is identified, the next consideration is the storage and distribution system within the building. Storage tanks, often categorized into overhead tanks and underground tanks, are essential components. Underground tanks store water from the main supply or wells and act as a reservoir to meet sudden demands or interruptions in supply. Overhead tanks, typically placed at a higher level such as the terrace, provide the necessary pressure for distributing water throughout the building via gravity. Proper sizing