What was the name of the standard that first introduced fixture unit tables?

The correct answer is that the standard that first introduced fixture unit tables is BMS 65. This standard was pivotal in establishing fixture unit tables used to calculate the load generated by plumbing fixtures in a system. The fixture unit system allows for a standardized way to assess the demand on a plumbing system based on the number and type of fixtures used. This helps designers ensure that piping systems are adequately sized to handle both peak demands and typical usage scenarios.

Other standards listed, such as ASHRAE 90.1, focus on energy efficiency guidelines rather than specific plumbing fixture load calculations. The IPC (International Plumbing Code) and UPC (Uniform Plumbing Code) standards guide plumbing design practices and may reference fixture units, but they did not pioneer the concept like BMS 65 did. Understanding the historical context and application of these standards reinforces the importance of BMS 65 in the evolution of plumbing design practices, particularly relating to fixture units.