What is the minimum size of a water service line for a single-family dwelling?

The minimum size of a water service line for a single-family dwelling is 3/4 inch. This size is deemed sufficient to provide an adequate flow of water for typical residential needs, including daily activities such as bathing, cooking, and laundry. A line of this diameter can typically sustain a household’s demand without significant pressure loss, ensuring that fixtures operate effectively.

A smaller diameter line, such as 1/2 inch, may not provide adequate water volume, especially during peak usage times, which can lead to inadequate performance of various fixtures. On the other hand, a line sized at 1 inch or greater is generally reserved for larger applications or multi-family dwellings where higher water demand is expected. A 2-inch line, while it can certainly accommodate a high volume, is excessive for a standard single-family home, both in terms of cost and practicality for standard residential use. Thus, 3/4 inch stands as the most appropriate minimum size for the typical water service line in a single-family dwelling.