Installing efficient water-saving technologies (taps, showers, toilets) in new-build homes in Ireland could save €280 annually in a four-person house when associated energy savings are also included.

And when scaled up to consider the 303,000 new homes mooted by 2030 in the government’s Housing for All targets, they could cut about €9.7m in state costs for water and wastewater services.

Value of Water Conservation report

This is according to a recently released Value of Water Conservation report commissioned by An Fóram Uisce/The Water Forum and compiled by Professors John Gallagher and Laurence Gill from Trinity’s School of Engineering.

The report’s findings come from a baseline scenario with a water consumption rate of 110 Litres per Person per Day (LPD), which is reflective of an already water-efficient home.

The report’s key finding is that reducing usage by 20 LPD can be achieved by installing more efficient taps, efficient showers and low-flush toilets. More savings could be achieved in households that currently exceed this rate of water usage.

Prof Gallagher said: “The installation of reasonably priced water-saving technologies would cost developers less than €180 per household, and pay itself back in three to four years, as it could save €50 per household in water treatment costs annually."

"When you also factor in the energy savings that come with them, homeowners could save up to €280 annually, primarily from the more efficient taps (€120) and showers (€160).

“People are often told that investing in sustainability measures isn’t always cost effective, but these efficiency-based solutions would make a significant impact for both their pockets and the planet. The cost-benefit is clear!

Free up 2.2 million cubic meters of water annually

"Crucially, if the government can deliver its ambition of 303,000 new homes by 2030, it could free up 2.2 million cubic meters of water annually to reduce potential limits on development, and cut about €9.7m in state costs for water and wastewater services.” 

The report does outline that retrofitting homes can incur higher costs and involve longer paybacks compared to new-builds, thus greater incentives may be needed to encourage replacing existing systems.

Despite the clear benefits of rainwater harvesting to offset demands in the home – like toilet flushing – its high cost represents a significant stumbling block at present for widespread installations. However, it does present a solution for specific areas of the country to deliver big water savings and support housing targets and thus economic growth.

Uisce Éireann recently indicated there are supply constraints in specific areas of the country to meet the government targets for housing, but the researchers behind this report suggest that reducing water use at building scale could reduce water demand per household, and thereby increase capacity for housing developments. 

The report is available to read on the Water Forum website.