Search PlotNua
What are you looking for?
AI-generated illustration — not a real installation.
What if your garden wall could store the rain?
A slim storage wall can collect the rain from your roof and keep it for the garden, standing quietly along a boundary you already have.
AI-generated illustration — not a real installation.
The possibility
Every downpipe carries the rain from your roof straight to a drain. A few weeks later, in a dry spell, the same garden is watered from the tap.
A rainwater-storage wall keeps some of that water. It is a tall, slim tank, about the depth of a garden bench, that stands along a boundary or the side of a house and fills from the downpipe. Its face can be planted, screened or simply left as a clean, dark plane.
The idea
A water butt holds enough for a few watering cans. A storage wall is a different scale of idea: about a thousand litres in a single slim panel, and a boundary that does a job.
The familiar answer: a tank on a stand beside a downpipe, with a tap at the bottom.
A tall, slim tank designed to stand along a boundary or a façade, or as a screen in its own right.
Illustrative drawings by PlotNua, not to scale and not designs for any garden.
The idea isn’t a bigger water butt. It’s a boundary that collects the rain.
How it works
The principle is the same as any rainwater tank. What changes is the shape: the storage becomes part of the garden’s architecture.
Stored rainwater suits watering beds, pots, vegetables and young trees, and washing tools or a bike. It isn’t treated, so it isn’t for drinking or cooking, and a garden-only system has no connection to the mains supply.
A tap and a watering can need nothing more. A pump that feeds a drip line or a timer needs power: where that means new outdoor wiring, use a Registered Electrical Contractor.
The practicalities
A full storage wall is heavy, tall and close to a boundary. That’s why a full-sized one is not a simple DIY project. These are the questions to settle first.
What each point depends on is your site: the ground, the wall beside it, the drains and your neighbours.
Established
Physical facts and the rules that apply. Each item notes who should confirm it for your garden.
A litre of water weighs a kilogram, so a full 1,000-litre module weighs about a tonne, plus the tank itself, on a narrow strip of ground. That load has to be carried by a properly prepared footing, not by soil, paving or an old patio.
The base should be designed for the filled weight and your ground, by the installer or a structural engineer. Makers publish base requirements for their own tanks: follow them, and keep the paperwork.
A typical block boundary wall is designed to stand up, not to carry a tank. A storage wall should stand on its own footing, with any fixing to a wall or posts designed for the purpose.
Full, a storage wall is heavy. Empty, a panel about 2.25 metres long and 1.75 metres high is light and catches the wind like a fence panel. Anchoring and bracing should be designed for an exposed site, especially if it stands freely as a screen.
In a downpour the wall fills quickly. The overflow must go back to the existing downpipe and drain or to a suitable soakaway, never onto a neighbour’s garden, a path or a wall. Check that the gutter and downpipe are sound before connecting anything.
Irish winters are mild, but exposed taps, hoses and pumps can freeze. Many tanks have a low outlet for draining down, and many downpipe filters have a winter setting. Ask the maker what the tank itself is rated for.
Garden walls and fences around a house are generally exempted development up to 2 metres high, or 1.2 metres in front of the house, subject to conditions. Whether a storage tank counts as a wall or fence isn’t settled. If in doubt, a Section 5 declaration from your local authority gives a formal answer.
On or against a shared boundary, agree it with your neighbour before anything is built, including access for the work and for maintenance. Where the boundary wall itself is shared, it isn’t yours alone to load or alter.
Confirm individually
Practical guidance. The answers depend on your garden and the product.
For a full-sized storage wall, plan on professional installation: a landscaper or groundworker for the footing, the maker’s installation guidance for the tank and its fixings, a structural engineer where the load, the ground or the wind exposure calls for one, and a Registered Electrical Contractor for any pump wiring. Ask the maker whether its warranty depends on professional installation.
The roof area that drains to the chosen downpipe, multiplied by the rainfall in millimetres, gives a rough idea of how many litres could be collected. A large wall on a small roof may rarely fill; a small one on a big roof will overflow often. Your installer can size it to the roof.
Choose a fully closed tank with a secure lid or no open top. Even a small depth of water is a drowning risk for a young child.
Clear the gutter and the downpipe filter regularly, especially in autumn, and leave room to reach the filter, the tap and any pump. A closed, dark tank helps keep algae down.
Irish households don’t currently pay domestic water charges, so a storage wall shouldn’t be expected to reduce a water bill. Its value is in having water for the garden through dry spells, watering plants with rainwater, using less treated water outdoors, and a boundary that does a job.
What exists today
Rainwater-storage walls are made and sold in Europe. Here is what PlotNua found, with the prices those sellers advertise.
In Ireland
Not yet confirmed through an Irish distributor.
When PlotNua checked on 4 November 2026, we couldn’t find an Irish distributor or installer offering a genuine rainwater-storage wall. That may change, and PlotNua can’t say if or when. What you can buy in Ireland today are slimline wall tanks, shown last below.
A modular storage wall: about 1,000 litres in a module about 225 × 175 × 30 cm, which can stand along a façade, as a rainwater fence or on its own. A filter and brackets are included. It is sold through dealers in several European countries; Ireland is not among those it lists. Maker claim
€1,050–€1,099 for one moduleRecommended price in the Netherlands and Belgium, including 21% VAT. Delivery, pump and installation extra. Advertised figure, checked 4 November 2026.
An Australian design of very slim tanks for walls, fences and side passages. The 1,000-litre tank is about 2.4 metres long, 26 cm deep and 2 metres high, and the maker says it must stand on a solid base or slab. A German retailer sells the range in Europe. Maker claim
€1,099 for the 1,000-litre tankRetail price at Zisternenprofi.de, Germany, including German VAT; free delivery within Germany only. Advertised figure, checked 4 November 2026.
Not a storage wall, but the nearest thing on sale in Ireland: slim tanks that stand against a wall beside a downpipe, from about 100 to 650 litres. Irish garden centres and online sellers carry smaller slimline butts.
€381.30 for a 650-litre wall tankGRAF Classico 650 L at tanks.ie, including VAT, with free delivery in Ireland; a 330-litre slim wall butt is €219.64. Advertised figures, checked 4 November 2026.
Products are described from the sellers’ own pages, checked on 4 November 2026. Prices change and differ between countries; the European prices are not Irish prices. No manufacturer’s photographs are shown. PlotNua has no commercial relationship with any business named here, none is a PlotNua partner, and PlotNua doesn’t sell, import or install any of these products.
Last checked 4 November 2026. PlotNua is an independent discovery platform and does not recommend or endorse any business mentioned; no business named here is a PlotNua partner. Statements marked “Maker claim” summarise what manufacturers publish about their own products. The garden images on this page are AI-generated illustrations, not photographs of a real installation; the drawings are simplified PlotNua illustrations, not to scale.
The homeowner decision
Your next step
Explore the concept yourself
Read how it works and what it asks of a garden, look at the European examples and the tanks you can buy in Ireland today, and take our questions to any installer you talk to.
Tell PlotNua you’re interested
Would you consider a storage wall in your garden? Send us a free message. It helps us understand whether Irish homeowners want these, and we’ll share what we find out.
Free for homeowners.
Start your message with the reference WW so we know it’s about the Water Wall. Prefer email? Use our contact page and mention “WW”.
PlotNua doesn’t sell, import or install storage walls or tanks, can’t say if or when they’ll be available in Ireland, and can’t confirm that a garden is suitable; that needs a site visit. Nothing is ordered, reserved or paid for by sending a message.
Whoever you talk to, these questions help you compare like with like.
