Rapid population growth in Nairobi has created a strain on the available water sources for use in homes. This has led to water shortages in residential set-ups such as multi-storey residential buildings. The reuse of grey water offers a solution to this problem by minimizing the supply and demand deficit of water, owing to the fact that a significant amount of grey water is produced every day from residential houses in Nairobi. The successful implementation of any grey water treatment system depends largely on its characteristics in regards to its pollutant strength. This study evaluated the physical and chemical characteristics of grey water namely, turbidity, pH, suspended solids, BOD and COD. They were analysed for grey water samples from households in a residential building in Madaraka Estate, Nairobi. The characteristics of grey water vary from household to household depending on the household practices, products used, the number of residents in the building among other factors. The pH for kitchen sources were found to be lower than bathroom sources and can be attributed to fats and oils as well as food particles present in kitchen grey water. The relatively higher values of pH for bathroom grey water sources can be attributed to the alkalinity of the detergent and soaps used. The study also assessed the use of alum as a treatment agent for domestic grey water treatment. It was determined that the concentration of alum required to clear turbidity of domestic grey water was uneconomical. A case study of a greywater treatment system used in Nairobi known as Klaermax Air Waste Water Treatment System was also assessed. The case study demonstrated that the treatment system is viable and cost efficient in the long run. The major difficulty in treating grey water is the variability in the quality over short time spans. The COD, BOD and other nutrient concentrations in the sampled grey water present values which indicate that further treatment is necessary before reuse. The study showed that the grey waste water produced from the houses is easily biodegradable.