Rainwater and Greywater Harvesting

At 21 Degrees, we are passionate about creating homes that are not only comfortable and healthy, but also truly sustainable. A common question we encounter from clients embarking on their self-build or renovation journey is how to best manage water consumption. Naturally, rainwater and greywater harvesting systems come into the conversation.

These technologies promise to reduce our reliance on mains water by recycling the water we use or capturing the rain that falls on our homes. But are they always the most effective solution from a financial and environmental standpoint? Let's explore the details.

Understanding Water Harvesting Systems

First, it's helpful to distinguish between the two main types of systems:

• Rainwater Harvesting: This involves collecting the rainwater that lands on your roof and storing it in a tank. This water is then typically used for non-potable purposes such as flushing toilets, watering the garden, or for the washing machine.
• Greywater Recycling: This system takes the used water from your baths, showers, and sinks (known as greywater), filters it, and re-uses it for tasks like toilet flushing.

The Environmental Balance: A Considered Approach

While capturing and reusing water seems like an obvious environmental win, the reality is more nuanced. For many private domestic projects, the overall environmental impact of installing and running these systems can unfortunately outweigh the benefits of the water being saved.

This is because the systems themselves have an environmental footprint. The production of the tanks, pipes, and filters requires raw materials and energy. Furthermore, the pumps needed to move the water consume electricity, and the systems require ongoing maintenance, which may involve a technician travelling to your property.

For this reason, the AECB Water Standard does not place a heavy emphasis on these systems for every project. It recognises that their higher cost and embodied environmental impact can make them less sustainable than simply using mains water efficiently. Our focus is always on the complete picture of sustainability, ensuring that a solution in one area doesn't create a problem in another.

When are Harvesting Systems the Right Choice?

This is not to say these systems don't have their place. In certain situations, they can be an excellent and appropriate choice:

• Large-scale projects: For commercial buildings or developments with very high water demand, the savings can justify the initial investment and environmental cost.
• Properties off the mains grid: In rural locations where a mains water connection is unavailable or unreliable, harvesting systems are a practical necessity.
• Areas with water shortages: In regions prone to drought or with specific planning requirements, these systems are a vital part of water resource management.

Our Recommendation for Your Home

At 21 Degrees, our philosophy is to provide knowledge and technology that is genuinely effective for your specific objectives and resources.

If, after careful consideration, a rainwater harvesting system is deemed appropriate for your project, we believe in using the best specialists in the field. This is why we confidently recommend the expertise of Rainharvesting Systems Ltd. Their dedicated team can provide a solution that is correctly specified and installed for maximum efficiency.

For any further guidance on designing a truly sustainable and water-efficient home, please don't hesitate to get in touch with our team.