Besides a sufficient energy supply, concepts for accommodations require an intelligent water management. Using the example of quarters that do not have water and energy access, a dynamic simulation model is presented in which a rainwater harvesting concept is implemented and simulated over one year using MATLAB-Simulink. The aim is to minimize respectively suspend the use of fossil energy sources and to guarantee the provision of decentralized clean drinking water. Since traditional water bodies, e.g. groundwater, are increasingly polluted and depleted, utilisation of alternative sources is prudent. Especially in rural areas, where access to drinking water is scarce, rainwater is suitable for providing potable water. Besides its beneficial chemical water properties, it is easily accessed in a decentralized manner, which makes it a preferred choice in areas with sufficient precipitation. However, access to rainwater is limited by its occurrence and contamination, calling for proper storage, utilisation, and treatment strategies. For this purpose, a rainwater harvesting system, including different water and energy management systems, was modelled and implemented using the site of the Angkor Centre for Conservation of Biodiversity in Cambodia as an example. For the simulation, a precipitation generator was implemented using real historical rain event data. An appropriate rainwater treatment process was chosen, consisting of a microfiltration and a subsequent ultrafiltration unit removing bacteriological loads entirely. Both were modelled and implemented dynamically. Using the site of the Angkor Centre of Conservation of Biodiversity, a complete rainwater harvesting plant was implemented including harvest, storage, and utilization of rainwater. Further, a renewable energy management strategy is developed, using photovoltaic modules and batteries. It was shown that the cumulative runoff meets the water demand of the Angkor Centre for Conservation of Biodiversity and that the energy demand of the rainwater system as well as the site can be met by the installed photovoltaics on the existing roof area.