Designing out water waste

With schools under pressure to cut costs and meet net zero targets, water efficiency is a great place to start. Richard Braid, Managing Director of Cistermiser, explains how smarter washroom technologies offer an opportunity to reduce waste, lower bills and shrink carbon footprints across education estates. 

Schools are being challenged to do more with less, balancing tight budgets with ambitious sustainability goals. While energy efficiency often takes centre stage, water waste directly increases utility bills and adds to a building’s carbon footprint. For schools, universities and public buildings aiming to reduce overheads and contribute to net zero, water efficiency is a key part of the solution. 

 The UK is facing mounting challenges when it comes to water supply and demand. With drier summers, an ageing infrastructure and a growing population, the country is heading towards a daily shortfall of 5 billion litres of water by 2050. Alongside the risks of shortage, treating and transporting water is extremely energy-intensive; across the UK, 15 billion litres of treated water is delivered every day, supported by more than 7,000 treatment sites and enough underground pipework to stretch to the moon and back. This generates millions of tonnes of greenhouse gas emissions annually. Reducing demand, therefore, lowers operational costs while reducing emissions associated with water treatment and distribution. For education estates with large facilities and high footfall, the opportunity to deliver savings at scale is significant. 

Hidden drains  

In schools, universities and other education buildings, monitoring day-to-day water usage is challenging. Problems such as leaking toilets, ageing cisterns and uncontrolled urinals often go unnoticed, wasting large volumes of water. Across non-household properties, data from Thames Water highlights that almost a third of water supplied shows as continuous flow (water running above 1 litre per hour for at least 14 days), often linked to undetected faults in washroom fittings. 

Older urinal systems are a major source of wastage. Many are set to flush automatically at fixed intervals, often three times every hour regardless of occupancy – even during evenings, weekends or school holidays. A single urinal with a 7.5-litre cistern can waste up to 197m³ of water annually, costing over £400. 

Toilets with traditional flush valves are also prone to leaks due to seal degradation caused by scale, wear and debris. Between 5 to 8% of UK toilets are estimated to be leaking – a huge issue as a single leaking toilet can waste around 400 litres every day (nearly 150,000 litres annually), adding up to £300 per fixture in costs. Even taps contribute to the problem. A simple dripping tap can waste than 5,500 litres of water a year, while taps left running in busy washrooms add significantly to consumption. 

Smarter solutions  

Fortunately, technologies exist to help schools tackle these challenges. For urinals, the Cistermiser Direct Flush system removes the need for the auto-flush cistern and associated plumbing used in traditional urinals. Instead, it uses infrared PIR sensors to detect when a urinal has been used, flushing only when necessary. Installing just one can save up to 182,000 litres of water and around 0.62 tonnes of CO₂ emissions per year.  

For toilets, the Easyflush EVO sensor activated WC dual flush has been designed to save water and be sustainable. With no seal below the waterline, it will not leak due to debris, scale or degradation and saves up to 146m³ of water per year – equivalent to £443 in utility bills and 0.05 tonnes of CO₂.  

Taps can also be optimised. Cistermiser’s Vecta+ taps, designed to flow at 5 litres/min, cut water usage by 161m³ per fitting per year compared to standard taps. They’re sensor-controlled to avoid being left running, making them ideal for high-traffic environments. In many cases, the return on investment is achieved within months, making them a strong financial and environmental choice. 

For designers, developers and managers involved in newbuild educational projects, water efficiency should be factored into specification decisions from the outset. Addressing leaks, removing uncontrolled flushing and installing smarter fixtures can help educational buildings meet both budgetary constraints and sustainability expectations.  

www.cistermiser.co.uk