As space heating decarbonises, hot water will soon become the primary energy load in homes. Paul Ravnbo-West from Triton Showers examines why it must not be overlooked in policy changes and outlines a scalable solution.
The steer of both the incoming Future Homes Standard (FHS) and last year’s consultation on updating Part G of the Building Regulations is clear: homes must consume less energy and water. That won’t be a challenge.
Published in January, the Warm Homes Plan committed £15 billion to helping households decarbonise and cut energy bills by adopting a trio of low-carbon technologies: heat pumps, solar PV and batteries.
While generally transformative in intent, the plan overlooks the need to reduce hot water consumption, which accounts for a significant proportion of domestic energy use. Instead of being folded into the narrative on heat, it deserves its own strategic focus.
Role of hot water
Despite the well-known challenges associated with heat pumps, their uptake will continue to increase, particularly once the FHS debuts, helping to decarbonise space heating. Hot water will consequently become the primary energy load in homes. This begs the question: why is it not directly treated in the Warm Homes Plan?
Hot water is almost always mentioned as a secondary load within those systems rather than as a first-order challenge in its own right. Even where the plan acknowledges that two-thirds of building emissions come from space heating and hot water, the policy instruments that follow overwhelmingly target the former.
At the moment, there is no equivalent of a hot water strategy, no demand-side framing and no explicit recognition that how hot water is generated can significantly change peak loads, infrastructure requirements and household costs. Hot water shouldn’t be viewed as a subset of heat, and if the Warm Homes Plan, or any future regulations for that matter, fails to address this explicitly, measurably and without equal fairness, the solutions available will remain invisible in the national narrative.
Enter electric showers
As the largest domestic consumer of water and responsible for generating half of hot water demand, showers are a fitting starting point for crucial gains. Instantaneous electric showers (IES) in particular provide instant hot water, decoupling it from space heating. This eliminates standing losses, distribution losses and, perhaps most importantly, saves on space, energy and running costs.
The next generation of high-efficiency instantaneous electric showers connected to wastewater heat recovery systems (WWHRS) can further reduce the energy required for showering. Heat recovered from shower wastewater increases the inlet water temperature, allowing the electric shower to reduce electrical input while maintaining the desired shower temperature and supporting consistent flow rates throughout the year.
Independent analysis conducted by Talan estimates notable at-scale savings could be made from deploying high-efficiency models manufactured to connect to WWHRS. It predicts annual energy use can be cut by up to 82.3%, water consumption by 45.7% and carbon emissions by 75.6%, compared to one of today’s conventional 8 litres per minute mixer showers. Additionally, £145 could be saved in annual running costs, with further lifetime savings available through fewer maintenance requirements and long-term operating costs.
This is especially important for hard-to-treat homes that face difficulties when fitting heat pumps and hot water cylinders, such as flats and terraced houses, where space and technical constraints limit retrofit options.
Decarbonisation drive
Triton’s latest report, ‘hot water down the drain: Unlocking hot water decarbonisation through the Warm Homes Plan’, urges the government to include IES and IES-HE within major retrofit and energy efficiency funding schemes, namely the Warm Homes: Social Housing Fund and the Warm Homes: Local Grant.
If adopted, these technologies could deliver up to 1,042 tonnes of CO2e savings in their first year and between 818 and 902 million litres of potable water savings over the next decade. This translates to up to an 87.5% reduction in shower-related emissions, compared to traditional mixer showers, by 2035.
To truly decarbonise hot water, there are several policy actions that must be taken. These include integrating hot water decarbonisation into the nation’s net-zero strategy and incentivising both consumers and housebuilders to invest in efficient shower technologies to meet upcoming water-use limits.
Policymakers must use the recent HEM:EPC consultation to update methodologies so they recognise advanced, high‑efficiency electric shower technology designed to connect to WWHRS. Removing green levies from household electricity from April 2026 would also reduce average bills by approximately £150 per year and is a good first step to support switching to low-carbon, electric-based systems.
Futureproofing today
As the UK strives towards net zero, it’s essential that the role of hot water isn’t overlooked. Electric showers are a simple, scalable and cost-effective solution to lower emissions, water usage and household bills. If enacted, these recommendations can play a pivotal role in both futureproofing housing stock and providing tangible savings to households today.
Triton’s white paper, ‘Hot water down the drain: Unlocking hot water decarbonisation through the Warm Homes Plan’, is urging the government to integrate hot water decarbonisation into its long-term housing and net-zero strategies, warning that hot water will soon become the dominant domestic energy load. You can download a copy by using the reader link below.
