Poor sanitation and poor-quality water supplies can lead to many diseases and illnesses. Good sanitation and plumbing systems within buildings are therefore essential and a key element of a buildings’ design. Within a typical building, the water services can generally be divided up into incoming (fresh) water supplies, and outgoing (waste) water systems. In this section, we will discuss how these systems are designed and installed within buildings, and how they are typically maintained. Plumbing systems on this website will focus only on the systems installed within a building and the immediate vicinity, and not larger-scale systems (such as utility-owned sewers and water processing plants etc.).
A potable (drinkable) domestic cold-water supply usually enters a building via an independent below-grade utility-owned main supply. Water is pressurized by the utility provider and supplied through pipework before being distributed around the building. Water can be distributed under the utility supplied pressure or boosted within the building by a booster pump system. To provide hot water for washing and bathing purposes, the domestic cold-water supply is split. The separated supply is then heated, usually by gas or electric water heaters where it is distributed as an independent hot-water feed to sanitary fittings within the building.
Within buildings, gas supplies are often provided for heating and cooking purposes. Gas supplies usually enter the building below grade through steel pipework, and the pipework connects into a meter before being distributed through the building via steel or copper pipework. As with water supplies, gas services are pressurized by the utility supplier which is sufficient for most buildings; however, in larger buildings and where large gas appliances are used, the gas service can be boosted via electronic pump systems which pressurize and regulate the gas supply.
Waste water is generated within a building from plumbing fixtures in bathrooms and kitchen fittings. Water is removed from a building via pipes which connect into municipally owned sewage systems, where it is then treated before being released back into natural waterways. Waste drainage runs are designed to discharge water based on gravity, although pumped systems are also utilized in buildings, if required. Stormwater (rain) is collected from a building via drainage runs which usually connect at site boundaries into municipal drainage runs, although in some buildings stormwater is collected in retention or detention systems before being discharged. As buildings become more energy efficient waste water can often be utilized. Greywater (also spelled graywater) systems collect non-harmful waste water from building systems, which can then be used for applications in a building where the water is not needed for cooking, drinking, or bathing purposes. An example of this may be the collection of water from bathroom sinks to flush toilets, or collection and storage of stormwater off a roof to irrigate a garden.