BuildInFlexergy: Transforming Existing Buildings into Flexible Energy Assets

Across Europe, electricity networks are increasingly reaching their limits. The rapid electrification of heating, transport and industry, combined with the growing share of renewable energy sources, is placing unprecedented pressure on the electricity grid. In countries such as the Netherlands, grid congestion has become a major barrier to further decarbonisation, delaying the connection of new buildings, and renewable energy systems. While grid reinforcement remains necessary, existing buildings can also become part of the solution by providing energy flexibility.

BuildInFlexergy is a Dutch innovation project that demonstrates how existing non-residential buildings can evolve from passive energy consumers into active participants in the energy system. Rather than replacing existing Building Energy Management Systems (BEMS), the project develops scalable software enhancements that integrate with current building automation infrastructures. This approach lowers implementation costs, accelerates deployment and makes advanced energy management accessible to a much larger building stock.

The project focuses on offices, educational facilities and healthcare buildings, where assets such as heat pumps, thermal energy storage, photovoltaic systems and electric vehicle charging infrastructure provide considerable flexibility potential. However, these systems often operate independently, preventing buildings from fully exploiting their ability to reduce energy consumption, support the electricity grid and maintain occupant comfort.

BuildInFlexergy combines data-driven forecasting using machine learning with Model Predictive Control (MPC) to optimise building operation. By continuously predicting energy demand, weather conditions, renewable energy production, occupancy patterns and operational constraints, the control system can anticipate changing conditions instead of simply reacting to them. This enables buildings to minimise energy consumption and operating costs while responding dynamically to electricity prices, CO₂ intensity and grid constraints.

A key innovation of BuildInFlexergy is the use of Key Performance Indicators (KPIs) as active control objectives rather than merely performance assessment tools. Inspired by the Smart Readiness Indicator (SRI), KPIs become optimisation targets that directly steer building operation in real time. Building owners can prioritise objectives such as energy efficiency, energy flexibility, operational costs, occupant comfort or sustainability reporting requirements, allowing the control strategy to continuously balance these competing objectives.

In practice, this means that a building can automatically adapt its operation to external conditions. For example, when electricity prices are high or local grid capacity is limited, the system may temporarily shift heat pump operation, optimise the use of thermal storage or postpone electric vehicle charging while maintaining indoor environmental quality within predefined comfort limits. Conversely, periods of abundant renewable electricity can be used to increase self-consumption or precondition the building, thereby creating flexibility without compromising occupant comfort.

To support building operators, BuildInFlexergy also integrates advanced monitoring and visualisation tools that provide continuous insight into energy flows, flexibility performance and operational KPIs. These dashboards facilitate data-driven decision-making and support compliance with emerging sustainability and reporting frameworks.

The project targets energy savings exceeding 20% together with a reduction in electrical peak demand of approximately 25%. In parallel, it investigates partial automation of software engineering processes to simplify the implementation of advanced control strategies and enable cost-effective deployment across large building portfolios.

By combining model predictive control, scalable digitalisation and KPI-driven optimisation, BuildInFlexergy demonstrates how existing buildings can actively contribute to Europe's energy transition goals. Rather than treating energy efficiency, energy flexibility and occupant comfort as competing priorities, the project demonstrates how intelligent building operation can balance these objectives, providing a pragmatic pathway towards affordable and scalable sustainability.