The average home uses around 250 000 l of water a year, but owners can significantly cut down on the amount drawn from the mains – and on their municipal water bills – by installing tanks to harvest rainwater from their roofs.

And these don’t have to be the massive and often unsightly installations of the past, says Berry Everitt, chief executive of the Chas Everitt International property group.

“Rainwater tanks come in many materials, shapes and sizes these days and can even be located underground with the water being pumped to home or garden piping. There are also ‘flat’ models that fit neatly against outside walls or can be incorporated into boundary fences.”

What is more, he says, you can use rainwater for much more than just watering your garden, even if you would prefer not to drink it. In fact, to really get the most out of having a tank, you need to have it connected by a plumber to the parts of the house that use the most water – the laundry, the kitchen and the bathrooms.

A washing machine, for instance, uses around 100 l a load, and a dishwasher up to 35 l a load, so using (free) rainwater for these functions would soon add up to a significant saving. Toilets use between 6 l and 11 l a flush, and a bath takes around 150 l and even a water-efficient shower around 9 l a minute.

Writing in the Property Signposts newsletter, Everitt says that if you do want to be able to drink the water from your tank, you will need to install various filters and may need to treat the water first. A professional installer in your area should be able to give you the details – and more important - will be able to work out how much rainwater runoff you are likely to get from your roof and what size tank or pump you need.

“Meanwhile, as well as lower water bills, you will have the satisfaction of knowing that you are doing your bit to reduce the physical impact of stormwater on drainage infrastructure, reduce contaminants in waterways and reduce the demand for increasingly scarce potable water from treatment plants.”