ABSTRACT
This research is focused on the design of water supply (cold and hot) system of a three bedroom bungalow with adequate pressure. Polypropylene (PP) pipes imported from Italy and polyvinyl chloride (PVC) pipes made in Nigeria, the two most common plastic materials used for potable water supply lines were selected for the analysis and compared to find out which of them is more cost effective, provide better form fitting and higher life expectancy. The adequate flow pressure required for both pipes was found to be 20 Pa while the standard pipe size for the supply of both cold and hot water was found to be 19 mm. The average diameter of branched pipes supplying water to the three bedroom bungalow was 13 mm. For cold water supply, pipes number „1? and „2? had 34 loading units while pipes 3, 4, 5, 6 and 7 had respectively 3.5, 6.5, 4.0, 6.5 and 13.5 loading units (LU). The loading units for hot water supply to the building for pipes number „20?, „21?, „22? and „23? were respectively 4.5, 4.0, 4.5 and 11.5 LU. Pipes made of PP, though more expensive, are more durable and have higher life expectancy than the PVS ones, and are resistant to weather factors such as temperature and humidity. PP pipes are recommended to be used to run both cold and hot water supply to the building, while PVC pipes can be used to run only cold water supply to the building since they can be easily damaged.