In reply to message posted by Robert Stephen Morton:
Zisi. In Queensland Australia, & I believe the rest as well we must have 5m head or fifty kilopascals thats about 5-6lb at any tap outlet with all taps on. We must pipe size the system to atain that output.
Same HERE at the uper most floors 6-8 PSI at the “faucet ” tap but many flushometers will not work under 35 PSI
The Code I normally use says the city is responsible to get water to the basement.
Reason being the water system here is gravity fed and many buildings are well over 47 stories heigh so the city will not be responsible for getting water this height.
But lucky we have foreign trained mechanics Like Canada to install the proper sized pumps and piping systems.