Unlocking up to 40% Energy Savings: How Digital Optimisation Transforms Building Heating Systems in Europe

Image building grey

Heating and cooling is at the heart of Europe’s energy challenge. Buildings account for 40% of the EU’s total energy consumption [Energy Balances, Eurostat, May 2025], with heating and cooling demand alone responsible for over a quarter of final energy use [Energy consumption in households Eurostat, June 25]. Yet, most buildings still operate oversized, misconfigured heating systems, often running at unnecessarily high supply temperatures, wasting vast amounts of energy and blocking the integration of low-temperature heating sources.

Drawing on real-life case studies of digital solutions implemented in Germany, Denmark and Spain, this brochure demonstrates how data-driven heating system optimisation, enabled by submetering and smart control technologies, can tackle these inefficiencies and unlock sustained energy savings of 20 – 40% without requiring structural changes or major investments, while maintaining thermal comfort of residents.

Digital optimisation achieves these results by using consumption and temperature data to adjust heating system settings, improve hydraulic balancing, and lower return temperatures, ensuring that the energy is delivered in the building in the most efficient way possible, only when and where it is needed.

Beyond reducing energy waste, optimisation solutions make buildings ready for low-temperature heating solutions, such as heat pumps and district heating, and therefore directly support the decarbonisation objectives of the Energy Efficiency Directive and the Energy Performance of Buildings Directive.

Find our Brochure, featuring seven case studies on heating system optimisation, here.

Based on these findings, WE Data Europe recommends the following points to be taken up in the Heating & Cooling Strategy as well as in the Electrification Action Plan:

  1. Introduce a dedicated digitalisation chapter
  2. Prioritise data-driven optimisation of heating systems in investments on buildings efficiency
  3. Favour digital metering over drive-by or walk-by systems to maximise the benefits of remotely readable meters
  4. Ensure the full and consistent implementation of the Energy Efficiency Directive across Member States.

Find our full set of Policy Recommendations here.

Download the Brochure
Download the Policy Recommendations

WE Data Europe Study Confirms Smart Water Metering Can Cut Household Water Use by up to 25%

Macro picture of water drop

Brussels, 30 September – WE Data Europe today publishes a landmark pan-European study confirming that water metering and sub-metering can reduce household water consumption by up to 25%, directly supporting the EU’s Water Resilience Strategy target of a 10% improvement in water efficiency by 2030.

About the Study

Commissioned by WE Data Europe and conducted by VITO, the study analysed water consumption data from six EU Member States, complemented by expert interviews and a wide literature review. It is the first analysis of its kind at European scale, providing robust evidence on the impact of smart water metering.

Key Findings

  • Metering works: Installing individual water meters where none previously exist typically cuts water use by up to 25%.
  • Digital meters deliver more: Switching from analogue to digital meters saves an additional 5–8%, while enabling leak detection and real-time feedback.
    • Leak detection is powerful: Buildings with such systems consumed 7–14% less water.
    • Behavioural change matters: Real-time information helps households prevent waste and use water more mindfully.

Country Highlights

  • Belgium: Leak detection cut water consumption by 13.6%.
  • France: Leak detection reduced use by 7.5%.
  • Germany: Consumption-based billing lowered consumption by 5.1%.
  • Denmark: Digital meters cut long-term water use by 5.2%.
  • Spain: Digital meters reduced consumption by 12.3%.
  • The Netherlands: Digital meters brought sustained reductions of 6.2% over several years.

Policy Context

The European Commission’s Water Resilience Strategy (2025) calls on Member States to improve water efficiency by at least 10% by 2030, explicitly pointing to smart metering and digitalisation as key tools to empower citizens and businesses.
In 2026, the Commission will present an EU-wide Action Plan on Digitalisation in the Water Sector, including a Smart Water Metering for All initiative. The findings of this study demonstrate the scale of potential savings and provide timely evidence for why such EU-wide measures are needed. 

The full study is available for download here.

Delivering on Water Resilience: What Can We Look Forward to

Reflection image of a building in the water

The Water Resilience Strategy sets out a long-term vision centred on three core objectives: restoring and protecting the natural water cycle; building a water-smart economy; and ensuring clean, safe, and affordable water and sanitation for all. To support the achievement of these goals, the EU is planning to act across five key areas: governance, financing, digitalisation, research and innovation, and security. Each area will be supported by targeted flagship actions, scheduled from 2025 to 2029. But will the Strategy live up to its expectations? This remains an open question as it follows two previous attempts from the Commission to address similar challenges: The 2007 Communication on Water Scarcity and Droughts, and the 2012 Blueprint to Safeguard Europe’s Water Resources.  

A Look Back: Previous Initiatives and Political Context  

Already in 2007, the Commission had stressed the urgent need for Member States to improve water efficiency in light of growing water stress across the continent. By 2012, it renewed its warning and urged river basin authorities in Member States to set water savings targets based on water stress indicators. A common EU methodology for setting these targets was planned for 2014 but ultimately failed to materialise. This raises a crucial concern: What makes the current Strategy more likely to succeed? 

The earlier initiatives relied heavily on the implementation of the Water Framework Directive and were limited to supporting Member States in achieving the ecological status targets for their water bodies. Since then, the EU water acquis has evolved, notably through the recast Drinking Water Directive, introducing new provisions focused on water quantity management and consumer information. As a result, the Water Resilience Strategy now benefits from a more mature and comprehensive policy framework on which to build more long-term actions for water efficiency. 

Meanwhile the EU has experienced an unprecedented succession of extreme climate events, spurring public support and national initiatives on water management.  This growing alignment between public opinion, national action, and EU-level commitment, underlines future willingness amongst Member States to implement the EU agenda on Water Resilience.  

Towards Implementation: Financing, Implementation and Mid-Term Review  

The Strategy’s implementation will be backed by financial support. The European Investment Bank’s Water Programme is expected to finance over €15 billion in water-related projects between 2025 and 2027. In addition, EU funds will be used to support pilot projects aimed at reducing leakage rates, including through the deployment of digital tools and smart water metering. Looking further ahead, the Strategy is aiming to ensure long-term sustainability through the 2028–2034 Multiannual Financial Framework, highlighting the opportunity this future EU budget offers to align investment and reform efforts with its objectives. 

However, as complex negotiations between Member States and EU institutions unfold in the coming years, it remains uncertain whether the recommendation to embed water-related priorities in the next MFF will be taken up. 

Another strength of the Water Resilience Strategy is its commitment to regular monitoring and implementation reviews, a critical element missing in previous initiatives. Starting in December 2025, the Commission will convene a Water Resilience Forum every two years, bringing together a wide range of stakeholders to discuss progress, monitor implementation, and exchange best practices. 

In addition, in 2027, the Commission will conduct a mid-term review of the Strategy’s implementation, including a first evaluation of the uptake of the Recommendation on Water Efficiency First. Based on its findings, some of the actions may be updated or revised, a positive sign that implementation of the provisions will remain a central focus. This will be followed in 2029 by a full evaluation of the national actions taken under the Strategy and the Recommendation, potentially informing updates to the targets and the introduction of new measures, including potential new legislation.  

Which policy outlook for the building sector? 

The Water Resilience Strategy identifies the building sector as a priority for improving water efficiency. As highlighted in our previous article, digitalisation, particularly through the Smart Water Metering for All initiative, offers key opportunities to enable and translate the provisions of the recast of the Drinking Water Directive into practical benefits for consumers while improving the water efficiency of the building stock. Under the revised Directive, Member States are required to develop, by 2028, national action plans to reduce their infrastructural leakage rates. The digitalisation of water management in buildings opens the door to a holistic leakage reduction strategy from source to tap, helping to save substantial volumes of water. It also improves resource affordability, tackling – for example – in-building leaks which often remain undetected yet are billed to occupants.  

Looking ahead, the 2026–2027 work programme of the New European Bauhaus initiative provides a promising vehicle to advance water-resilient design and planning in buildings.  These objectives are expected to be reinforced through the Affordable Housing Plan, scheduled for Q1 2026, which could embed requirements or incentives for improved water efficiency in buildings. This effort will be further supported by the Ecodesign for Sustainable Products and Energy Labelling Work Programme for 2025–2030, which will expand its scope to help consumers equip their homes with more water-efficient products and appliances. 

The building sector stands out as a strategic entry point to translate policy ambition into measurable impact. The Water Resilience Strategy provides a concrete framework for action and it is now up to Member States to seize this momentum and scale up their efforts across all sectors.  

Overall, the Water Resilience Strategy sets out a more structured, better funded, and politically supported roadmap than its predecessors. While success is not guaranteed, the conditions for meaningful implementation appear stronger than before. One area where this potential can be clearly observed is the building sector, a recognised priority for advancing water efficiency and where the tools already exist that can make a difference. 

A New Era for Water Policy in Europe: The European Water Resilience Strategy

Macro picture of water drop

On June 4th 2025, the European Commission unveiled its long-anticipated Water Resilience Strategy. Sparked by the EU Blue Deal adopted by the European Economic and Social Committee in 2023 and fueled by the increasing frequency of droughts and intensifying water scarcity across the continent, the strategy offers a more integrated, forward-looking approach to water governance.

Continue reading