Cost of Installing Rainwater Harvesting System

Written-by

Richard Burdett

Reviewed-by

Richard Burdett

Updated on

Aug 06, 2023

Cost of Installing Rainwater Harvesting System

Calculating the cost of a setting up a rainwater harvesting system can be difficult as it depends on a range of factors apart from the initial outlay for the tank and pump system. If you are retrofitting to an old build this can also include:

• The cost of putting in the new conduit or piping to feed utilities like the toilet or washing machine.
• Shaping water collection from your roof with new guttering that feeds into your rainwater harvesting tank.
• Excavating the area outside your property if you are planning to have the water tank underground.

Installing a Water Meter is Free

Before you begin then you will need to have a water meter installed if you are going to get a return on investment on your utility bill. This is normally done for free when you contact your provider and can offer substantial savings in itself if you have a small family or low water usage already.

Cost of Domestic Rainwater Harvesting Systems

The cost of equipment for a rainwater harvesting system can vary between £2-3,000 for an average sized family home. As a rough guide we outline the cost for a number of systems below:

• The simplest type of rainwater harvesting is the water butt which is a free standing container that can be easily hooked up to a drainage system to collect runoff. These vary from about £70-80 for a 200 litre container to around £350 for a 1,000 litre system. They do not plug into any piping system and are generally used to provide water for the garden.
• A slightly more hi-tech kind of water butt is one that has a water pump installed. A 700 litre capacity system which includes filters can cost around £750 and allows you to make simple connections for a range of home uses.
• According to the UK Rainwater Harvesting Association the cost of an average, fully functioning domestic system will be between £2,000 and £3,000 excluding the price of installation. Other things that will also affect the overall cost is the amount of piping you will have to put in and the conversion of your roof to collect water. Most domestic situations suit a pump feed system rather than a gravity feed one.

Find out about the different types of rainwater harvesting here.
 

Cost of Installing RHS in your Home

The cost of installing a rainwater harvesting system is also going to depend on a number of factors, most notably whether you are going to have it above ground or below.
You need to take account of the amount of excavation needed if you are going to bury your system in the garden and this can add an extra £1-£2,000 to your installation. You can explore our database of installers in your area to compare prices.

Cost of Installing a Commercial Rainwater Harvesting System

Again, the cost of installing for commercial premises depends on the size and complexity of the system being put in, but rainwater harvesting on this scale can also present a quicker return on investment for many businesses. A system of comparable size to a domestic RHS will normally cost about the same, including the physical installation.

Commercial concerns can, however, find greater benefits by installing larger rainwater harvesting systems that provide excellent returns on investment, often within just a couple of years. As a guide, The National Trust recently installed two 4,800 litre tanks at Calke Abbey in Derbyshire. The cost, excluding VAT, including all pipes and relaying of turf was just under £12,000 and is primarily being used for watering the extensive gardens.

Other Ways to Save Water

Whilst installing a rainwater harvesting system to reduce your mains usage has a number of advantages, you can also save a lot of money and reduce costs by taking a more holistic approach to your daily consumption. These can include:

• Install a low flush toilet or put a plastic bottle filled with water into your cistern (reducing the amount of water it fills with). An average flush of a toilet uses around 13 litres of water each time you pull that handle.
• When you brush your teeth, don’t leave the water running. It sounds like a simple thing to do but many people waste water by letting the tap run for a whole two minutes while they polish those dentures.
• Buy a water efficient washing machine or dishwasher and only use when there is a full load, using the economy setting.
• If you have dripping taps then make the effort to buy new washers and mend them – it may not seem a lot but over a year can make you savings.
   

Simple changes to your daily routine can make a big difference to your water usage. That’s one of the reasons we recommend having a water meter installed, even if you have a larger size family, as it forces you to concentrate on the resources you use.