How many fixture units are assigned to a shower in a private residence?

The assignment of fixture units for a shower in a private residence is typically based on established plumbing codes, which calculate plumbing demand to ensure proper drainage and water supply. Showers are generally assigned three fixture units because of the average flow rate and usage expectations for residential bathrooms.

Fixture units serve as a standardized measure that takes into account the frequency and intensity of usage, helping to determine the sizing of plumbing systems. A shower is used frequently in most households and typically supplies water at a higher rate than other fixtures like sinks or toilets, thereby necessitating the higher allocation of three fixture units. This ensures that the plumbing infrastructure can adequately handle the demand without resulting in issues like insufficient water pressure or drainage problems.

Other options may represent different fixtures or be inaccurately low for the typical usage associated with showers, which could lead to undersized piping and inadequate water service if those numbers were used.