Water-wise house design for dry climate guide

Water-Wise House Design for a Dry Climate

28 October 2026

image : graphicverry on Magnifice

In a city like Adelaide, where summers are long and hot and rainfall is modest, water is something a good house design should take seriously from the first sketch. The choices made at concept stage decide how much water a home collects, how much it wastes and how easily it can adapt if water becomes more expensive or restricted in the future.

Water-wise design isn’t only about adding a tank at the end of the build. It works best when the roof, the plumbing layout, the fixtures and the garden are planned together. This article looks at the main elements and how they fit into a new home.

Start With the Climate and the Site

A dry climate shapes everything. Rain tends to arrive in bursts over the cooler months, followed by long stretches with little or none. A water-wise home is designed to capture that winter rain, store it and use it through the dry season.

Begin with the site. Note where water naturally runs across the block and where there is space for storage. Roof form matters too. A simple roof with fewer valleys makes collection easier, while a complicated roof can spread water across several downpipes that are hard to bring together.

Rainwater Tanks From Day One

A rainwater tank is far easier and cheaper to plan into a new build than to retrofit. At design stage you can choose where it sits, how large it can be and which fixtures it will supply.

Size should reflect the roof area available for collection and how the water will be used. Tanks used only for the garden can be smaller, while tanks plumbed into toilets and the laundry get used year round and pay their way faster. Slimline tanks can run along a side boundary, and some designs place storage under a deck or within the building footprint.

Plan for the details too: leaf guards and first-flush diverters to keep debris out, an overflow that connects safely to the stormwater system, and a pump with mains backup so toilets still work when the tank runs low.

Greywater and Plumbing Planning

Greywater is the lightly used water from showers, basins and washing machines, and it is a good reason to bring in professional plumbers in Adelaide while the drawings are still being developed. Reused on the garden, greywater can cut household mains water use noticeably, especially through summer. Kitchen water is usually excluded because of food scraps and grease.

Greywater systems need to be approved and installed correctly, so they belong in the plumbing plan from the start. Separate drainage lines are much easier to run during construction than after the slab is poured and the walls are lined, and a plumber reviewing the plans can point out what is practical on the site.

Adelaide Expert Plumbing & Gas, based in Thebarton, is one local business that covers this kind of work, listing bathroom and kitchen plumbing, stormwater drains, hot water systems and water filtration among its services. In South Australia, plumbing must be carried out by licensed plumbers, and a designer working alongside one early tends to avoid costly changes later.

Talk to your local council about approvals for greywater and rainwater connections, as requirements can depend on the system type and the site.

Efficient Fixtures and Short Pipe Runs

Every fixture in the house has a water rating, and choosing well is an easy win. Look for high star ratings under the national WELS scheme on showerheads, taps, toilets, dishwashers and washing machines. A dual-flush toilet and a water-efficient showerhead make a real difference over the life of a home.

Layout matters as much as fixtures. Long hot water pipe runs mean people waste cold water while waiting for the hot to arrive at the tap. Placing the hot water system close to the bathrooms, laundry and kitchen, or grouping these rooms together, shortens that wait. Insulating hot water pipes helps as well.

Consider where outdoor taps will go, too. Taps fed from the rainwater tank near garden beds make it easy to use stored water first, rather than reaching for the mains hose.

Designing the Garden to Match

The garden is often where most household water goes in summer, so it deserves attention at design stage. Choose local and drought-tolerant plants, group plants by water needs, and use mulch to hold moisture in the soil. Drip irrigation fed by tank water or greywater uses far less water than sprinklers.

Permeable paving, swales and rain gardens let stormwater soak into the ground rather than rushing straight into the street drain. They also help keep soil moist around trees through dry spells. Shade trees placed on the western side of the house cool both the garden and the walls, so the outdoor areas near the home need less watering in the hottest months.

SA Water, the state’s water utility, has useful guidance on water use, connections and saving water at home. You can find it on the SA Water website, and it is worth reading before you finalise your plans.

Bringing the Elements Together

A water-wise home is not built around one feature. It comes from a roof designed to collect rain, tanks sized for real use, greywater planned from the start, efficient fixtures and a garden that suits a dry climate. When designers and plumbers sit down together early, these pieces fit neatly into the build rather than being added at the end. The result is a house that copes better with hot summers and keeps its running costs down for years.

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