In plumbing water systems (PWSs), there are two main layouts for water pipe networks (WPNs)
within buildings: branched and looped layouts. The aim of this study is to introduce an approach for
improving the performance of PWSs using looped water pipe networks within buildings. This
approach is applied to a case study of branched configuration that is firstly changed to a looped
configuration with the same pipe diameters, secondly to a looped configuration with the same
discharge and velocity, and thirdly to the same branched configuration with double the pipe
diameters. All cases were analyzed for cost and hydraulic reliability in terms of resilience index,
minimum surplus head, failure index and demand node’s flow path. EPANET software was used for
hydraulic analysis of all cases. It is concluded from this study that replacing branched configuration of
PWSs by looped configuration improves the hydraulic reliability and minimizes the costs of the PWSs.