Is grey water recycling and rain harvesting financially viable?

Conserving drinking water may become as important as conserving fuel in the future and reusing water may become the norm sooner rather than later. But is it worthwhile installing systems to recycle our water now?

Recycled rain water for the garden

Let's consider the most simple option - the humble water butt which stores rain water. A downpipe carries the water from the roofs, directly into the top of the barrel.

A water butt not conserves water for future use and, were everyone to catch and store their roof rain water, localised flooding would be minimised.

On hot summers days we use a staggering 70 per cent of the water we get through per day just to water our gardens. By using saved water, not only is it good for the environment but (for those of us on water meters) good for the pocket too. Added to which, some plants respond better to rainwater than tap water anyway!

The water butt above will store 215 litres and costs just £49.99 more info click here. The average price of water has been estimated to be around 25p per litre. So if you use water for your garden, you'll be looking at getting your money back on the investment made fairly quickly.

Recycled water for domestic use

Water tanks come in many shapes and sizes. The one above is ideal for use in the garden. But you can get much larger ones, many of which are submerged below ground. A 2,800 litre tank tank complete with pipe work connections, submersible pump and water filter will cost you around £1,000. The water saved can be recycled not just for the garden but for domestic use too - for flushing toilets and for the washing machine.

If your water is to be recycled for domestic use too, an expert will be able to advise you on the size of tank you need which will be determined by a number of factors including:
1)The areas rainfall (and how much can be captured from the roof - better with sloped roofs than flat ones)
2) Projected demands on the tanks - generally related to the number of people in the house
3) Space in which to put the tank

Generally most domestic tanks are between 2000 and 5000 litres

Water usage in the home

The average Briton uses about 130 litres worth of drinking water a day. One third of this goes down the toilet!

Water is a resource that should not be wasted and yet we all turn on the tap without thinking. The day may come that potable water is in short supply and the future generations will be incredulous at our wastefulness.

* The grey water from these machines can be recycled if filtered and cleaned for use in toilets and outside. Filtered rain water can be used to clean the plates / clothes.

As the table above shows, most of our water can be reused or can be replaced with recycled water instead. So called "grey water" from our baths, showers and sinks can also be collected by running the drainage pipes directly to the storage tank. This water is then pumped into a header tank in the house (the standard pump delivers 4,500L/Hr at 4.55 Bar), which in turn feed toilet cisterns /outside hose pipes and is reused to flush toilets or for garden irrigation.

Rain water can be used for outside use, washing machines, dishwashers and toilets. Greywater is mildly contaminated (soap, skin oils, detergents etc) and requires a degree of treatment before it can be recycled for secondary (non-potable) use, such as cleaning, toilet flushing or irrigation.

By recycling water, you will be able to reduce your water consumption by 50%. You'll still need a mains supply for personal washing, washing up and for drinking water. But the 33% used to flush toilets, 13% for laundry and 7% for outdoors will be saved.

There are many different water recycling systems on the market. Treatment systems come under two main categories - physical and chemical systems. Physical systems (commonly used in small scale systems) use filtration to clean the water.

Chemical treatment is generally used in larger systems and works in a similar way to the processes used at a sewage treatment works. Some systems use a combination of the two methods.

Other systems exist that will filter and clean the water until it is potable

Installing a system for use in an individual property can be expensive. A typical, off the shelf, single house, domestic system may cost in excess of £3,000 to purchase and then their are the running costs and installation costs on top of that. It is generally accepted that the larger the family, the more financially viable they become.

If price is the most important factor, you will need to balance the savings made against the cost of installation and maintenance. However if you are looking to create an eco-friendly house by harvesting rain water, wish to cut your domestic water bills by as much as 50% without sacrificing hygiene or comfort and want a green garden despite a hosepipe ban then a water recycling system may well be ideal for you.

Once only of interest to a small minority, green is the new black as far as self-building is concerned.

With the effects of global warming becoming increasingly apparent, more and more people are seeking greener ways to provide the energy needed to run a home.

Whether it's solar panels, heat pumps, high specification glazing or eco-friendly wool insulation in the loft space, there is little doubt that it is self-builders who are setting the standards for a greener future for the building industry and the way we live our lives.

Underfloor heating for example, has been available for years but, by and large, the self build market has been the industry's bread and butter - with large scale property developers still opting for standard, less efficient radiators.

But it's not all about saving the planet. Incorporating green ideas into a home can lead to reduced running costs and save you money in the medium to long term too. And when you come to sell your home in the future, you can guarantee that the greener it is the more attractive it will be to prospective buyers.

There is a greater sense of purpose from the government to promote green alternatives too with a stick and carrot approach in place.

Building regulations now demand far better energy efficiency while government grants are available for loft insulation right through to solar panels, heat pumps, wind turbines and other microgeneration technologies.

Self-builders are leading the way as far as greener homes are concerned and greenselfbuild.co.uk will be with you every step of the way towards a greener future for you, your family and the wider community.