Rainwater Harvesting Typologies for UK Houses: A Multi Criteria Analysis of System Configurations

Academic research and technological innovation associated with rainwater harvesting (RWH) systems in the UK has seen a shift of emphasis in recent years. Traditional design approaches use whole life cost assessments that prioritise financial savings associated with the provision of an alternative water supply. However, researchers and practitioners are increasingly recognising broader benefits associated with rainwater reuse, such as stormwater attenuation benefits. This paper identifies and describes a set of novel RWH system configurations that have potential for deployment in UK houses. Conceptual schematics are provided to define these innovations alongside traditional configurations. Discussion of the drivers supporting these configurations illustrates the opportunities for RWH deployment in a wide range of settings. A quantitative multi criteria analysis was used to evaluate and score the configurations under a range of emerging criteria. The work identifies several RWH system configurations that can outperform traditional ones in terms of specified cost and benefits. Selection of a specific RWH technology is shown to be highly dependent on user priorities. It is proposed that the system configurations highlighted could enable RWH to be cost-effectively installed in a broad set of contexts that have experienced minimal exploitation to date.