Using this free, and plentiful, resource at home is good for the planet and your wallet. Nigel Griffiths discusses the essentials

Need to know:

Integrating some kind of rainwater harvesting system into a self build or renovation project has been growing in popularity for years, not only for the economical benefits, but also the ecological impact. But how can you maximise yield, reduce your demand for mains water and still achieve those all important financial savings?

To start you must understand the basics. As the name suggests the practice centres on the gathering and use of rainwater in the home instead of a mains supply. You can use it to flush toilets, run the washing machine and irrigate the garden. In most cases, the primary collection system is the roof – most already have a way to accumulate this thanks to guttering and downpipes, which can be used to convey water to a reserve. Although the exposed tops of buildings are not perfectly clean, they do not have all the contaminants that are present at ground level, and foreign bodies such as leaves can easily be removed.

In terms of storage, tanks can be situated above or below ground, but the former will require protection from freezing and may need to be disguised in some way as they are often unsightly. In order to use the water, it needs to be pumped from the unit, either directly to the points of use in the property or to a secondary header tank located elsewhere in the home, usually in the loft.