Wondering where your household water actually goes, and how to design your project for real water efficiency?

Discover how to choose water-efficient fixtures that don’t compromise on performance, and what the star ratings actually mean in practice.

Learn the design and plumbing decisions that can waste water in most homes, and how to address them in your renovation or new build.

Listen to the episode now.

Hello! This is Episode 411, and Way #11 of the 44 Ways to Create Your Sustainable Home series here on the podcast. We’re continuing through Section Three: Sustainable Services and Infrastructure, and this episode is about water.

Water tends to receive less attention than energy in a sustainability brief. I think this is partly because the financial feedback is less immediate. 

But around 12% of Australia’s water use is in residential homes, water is a finite resource under pressure in many locations around the world, and the decisions you make about how your home uses it can carry through for the life of the home.

Way #11 is: Reduce Your Water Use In and Around Your Home.

Interestingly, water efficiency can be one of the most straightforward areas to address, purely through specification. The ratings systems for water-efficient fixtures are clear and accessible, the products are widely available, and the cost difference between a high-efficiency and a standard fixture at specification stage is usually minimal.

Indoor household water use in Australia breaks down roughly like this: 

• showers approximately 34% 
• toilet flushing around 26%
• laundry approximately 23%
• taps around 12%
• and the dishwasher approximately 5%. 

Showers and toilets together account for roughly 60% of indoor water use, so if you want to prioritise water efficiency in your fixture selections, those are the two areas with the greatest potential impact.

The average Australian uses approximately 340 litres of water per day. 

Similar figures apply across other high-income countries, including the United States, United Kingdom and much of Europe. 

We use roughly a quarter of our daily water use, as drinking-quality water, to flush away waste in our toilets.

The WELS rating system in Australia, which stands for Water Efficiency Labelling and Standards, applies to most water-using products sold for residential use. Equivalent systems exist in other countries: WaterSense in the United States, and the EU Water Label in Europe. More stars means less water used.

If two adults in your household each shower for eight minutes a day, the difference between a three-star and a five-star showerhead is approximately 48 litres per day, or more than 17,000 litres per year. That’s about 85 bath-tubs worth of water difference, plus a significant volume of hot water energy that wasn’t spent heating it.

Beyond fixture ratings, there are design decisions that can meaningfully reduce water use, and they’re worth raising with your designer and plumber early. The placement of the hot water unit relative to the bathrooms, kitchen, and laundry is one of the most important. 

In a larger home, or one where the wet areas are spread across multiple levels or extended areas of the home, the wait time for hot water to reach a tap can add up to thousands of litres of wasted water per year.

Grouping wet areas together, and positioning the hot water unit close to the rooms that use it most, can reduce that wait time and the waste that comes with it. 

Getting this right is a design decision made during floor plan development, and it’s much cheaper to get right at the drawing stage than to address later.

In this Episode, I cover:

• Where household water actually goes, with the typical percentage breakdown across showers, toilets, laundry, taps and the dishwasher
• How outdoor water use changes the picture (we’re sharing more about that in the next episode)
• What the efficiency rating systems actually mean for your selections
• How much water (and hot water energy) you can save by moving up the star ratings on showerheads, toilets and taps
• The case for front-loading washing machines and efficient dishwashers, and how to evaluate them model by model
• Hot water layout, water pressure and plumbing configuration decisions that can quietly reduce water use

Plus a whole lot more.

LISTEN TO THE EPISODE NOW.

RESOURCES

WELS rating scheme (Australian Government water efficiency ratings) >>> https://www.waterrating.gov.au/ 

WaterSense (US EPA water efficiency program) >>> https://www.epa.gov/watersense 

Unified Water Label Association (Europe) >>> https://uwla.eu/ 

Michael Mobbs’ Sustainable House, water section >>> https://www.sustainablehouse.com.au/water 

’44 Ways to Create a Sustainable Home’ e-guide >>> https://undercoverarchitect.com/ways 

Access the support and guidance you need to be confident and empowered when renovating and building your family home inside my signature online program, HOME METHOD >>> https://undercoverarchitect.com/courses/the-home-method/