In the UK, rain is one thing we never seem to run short of. Yet most homes allow thousands of litres to disappear straight into the drains every year.
Rainwater harvesting changes that. It captures rainfall from your roof and stores it for practical use around the home — not just in the garden, but across a much wider range of everyday tasks.
If you're planning sustainable upgrades, landscaping improvements or a full renovation, water storage deserves serious consideration.
Why Rainwater Harvesting Makes Sense in Britain?
The UK has consistent annual rainfall across most regions. Even during drier summers, the rest of the year usually provides more than enough water to keep a storage tank topped up.
At the same time, water treatment and pumping require energy. Every litre of mains water carries both a financial and environmental cost.
Collecting rainwater reduces demand on the grid while giving homeowners more control over how water is used.
What Can Harvested Rainwater Actually Be Used For?
Most people think of watering plants — and yes, that’s the obvious starting point. But the real value goes much further.
Rainwater can be used for:
- Garden irrigation
- Washing patios, driveways and tools
- Cleaning bikes and cars
- Filling ponds or water features
- Supplying outdoor taps
- Flushing toilets (with proper system setup)
- Feeding washing machines in non-potable systems
- Backup water supply during restrictions
Toilets alone account for a significant portion of household water use. Using harvested rainwater for flushing can noticeably reduce mains consumption over time.
For larger properties or renovations, integrated pumped systems allow rainwater to supply multiple non-drinking uses inside the home.
Choosing the Right Rainwater Tank
Different homes require different solutions. Build Greener offers several tank types designed for UK properties and varying space constraints.
Slimline Rainwater Harvesting Tanks
Slimline tanks are ideal for terraced houses or compact gardens. Their narrow footprint allows installation along walls, fences or tight side passages.
They are durable, rust-proof and designed to cope with British weather conditions. Despite their modest size, they provide reliable storage for irrigation, cleaning and general outdoor use.
For many homeowners, this is the easiest entry point into sustainable water storage.
Underground Rainwater Tanks
For larger homes or renovation projects, underground tanks unlock far greater potential.
Because they are buried below ground, they preserve garden aesthetics while offering substantial storage capacity. This makes them suitable for supplying toilets, washing machines and multiple external outlets when connected to pump systems.
They also contribute to improved surface water management. During heavy rainfall, stored water reduces pressure on local drainage systems.
Installation is particularly straightforward when landscaping, extensions or driveway works are already planned.
Static Horizontal Water Tanks
Static horizontal tanks offer a practical middle ground.
They provide high-capacity storage without requiring excavation. Positioned along boundaries, under decking or in larger yards, they create a stable reservoir for:
- Large gardens
- Allotments
- Vehicle washing
- Outdoor utility supply
- Pump-fed systems
For properties with higher water demand but limited ability to dig underground, these tanks offer flexibility without compromise.
Environmental Benefits
Rainwater harvesting reduces reliance on treated drinking water for tasks that don’t require it.
Less demand means less energy used in water processing and distribution. Over time, that lowers your household’s environmental footprint.
Capturing rainfall also helps moderate stormwater runoff. In urban areas especially, reducing the immediate flow into drains can ease pressure during intense downpours.
When combined with sustainable insulation, permeable landscaping and natural building materials, rainwater harvesting strengthens your home’s overall resilience.
Financial & Practical Benefits
The savings accumulate gradually rather than dramatically. Yet over years of ownership, reduced water usage becomes noticeable.
More importantly, stored water provides flexibility. During hosepipe restrictions, you retain access to your own supply.
For households investing in long-term eco renovation, this isn’t just about cutting bills. It’s about building a more self-sufficient home.
When Is the Best Time to Install?
Rainwater tanks can be retrofitted at almost any stage.
However, installation is easiest during:
- Garden redesign
- Extension works
- Driveway replacement
- Drainage upgrades
Coordinating projects reduces disruption and ensures the system integrates properly with your home layout.
FAQs
What can harvested rainwater be used for in UK homes?
It can be used for garden watering, cleaning, toilet flushing, washing machines and other non-drinking purposes when installed correctly.
Can rainwater tanks supply toilets and washing machines?
Yes, with appropriate filtration and pump systems, harvested rainwater can supply non-potable indoor uses.
Are underground rainwater tanks better than above-ground tanks?
They offer larger capacity and preserve garden space, but installation is more involved.
Do Build Greener rainwater tanks suit UK weather conditions?
Yes, they are designed to withstand British climate conditions and long-term outdoor exposure.
Does Build Greener deliver across the UK?
We currently only ship to mainland UK. To enquire about shipping to a different destination, please contact us.