SP3: Deployment of energy-efficient buildings integrating RES, storage and frugal solutions

Key Developments in Alba Iulia’s Refurbishment Solutions in the PCED area

• Dorin Pavel Technological High School Complex Refurbishment – Energy-efficient renovation of six connected buildings, powered by rooftop PV systems (heat pumps, new condensing boilers, ventilation with recovery) and a smart Building Management System.
• CRESCENDO Campus Construction – Romania’s first near-zero dual-education campus under development, spanning over 25,000 sqm and designed to host more than 300 students and pupils.
• Smart LED Lighting System – A €14 million overhaul of the public lighting network in the PCED area, reducing energy consumption by 116 MWh/year and CO₂ emissions by 28 tons/year.
• Smart Connectivity & Digital Integration – All infrastructure upgrades will be connected to Alba Iulia’s growing digital systems to enable better monitoring and management.

Next Steps

• Finalize the rehabilitation and internal energy connectivity between the six Dorin Pavel buildings.
• Repair, replace and relaunch the PV and inverter system, and complete BMS installation at Dorin Pavel Technological High School.
• Complete public tender and begin construction of the CRESCENDO campus, including acquisition of equipment and definition of education programs.
• Continue system monitoring and testing for the LED lighting network.
• Operationalize all three projects, including final technical testing and integration with city digital platforms.

Lessons Learned

• Project Coordination is Key – Alignment between implementing departments and the original project teams is critical. Gaps in coordination can lead to delays and missed opportunities.
• Large-Scale Collaboration Requires Constant Dialogue – Building strong local consortia (as seen in CRESCENDO) depends on frequent informal&formal meetings to maintain engagement and align goals.
• Lifecycle Thinking Pays Off – Selecting solutions like smart LED lighting based on full lifecycle performance supports better value over time and simplifies integration with other smart systems.
• Resilience Through Redundancy – Temporary overlaps between new and existing infrastructure reduce public disruption and ensure seamless service continuity during upgrades.

Through an integrated portfolio of education, public services, and energy-efficiency projects, Alba Iulia is demonstrating how mid-sized cities can lead the way in urban sustainability. By focusing on energy-smart infrastructure and cross-sector partnerships, the city is building long-term resilience, lower emissions, and improved quality of life.
 

Key Developments in Budapest’s Refurbishment Solutions

• NZE Building Retrofit – The building will be adapted into 40–50 apartments and ground-floor services, all designed for near-zero energy performance.
• Heat Exchange Technology – Budapest Waterworks has developed a heat exchanger connected to the city’s potable water pipeline, supplying heating and cooling via an integrated heat pump system.
• Mixed-Use, Adaptive Reuse Model – By combining residential, collective and public functions, the project promotes social innovation and sustainable urban regeneration.
• Governance Collaboration – The Municipality of Budapest, IV District Municipality, Budapest Waterworks, BFVK, and EnviroDuna are jointly coordinating the refurbishment and energy system design.
   

Next Steps

• Finalize the public procurement process and appoint a design firm.
• Define the operational model for the co-housing facility.
• Complete the business model and cost feasibility study for the heat exchange system.
• Launch concept design and technical plans for the retrofit and mechanical systems.

Lessons Learned

• Multi-Level Coordination – Strong collaboration between municipal departments and utility providers is essential for integrating innovative technologies into building retrofits.
• Technology Readiness – The heat exchange system has completed the patent process and is entering the serial production phase.
• Demand & Design Alignment – The success of the heat system depends on aligning user behavior with system performance and adapting the building’s infrastructure accordingly.

Budapest’s pilot demonstrates a bold approach to zero-emission urban refurbishment by combining adaptive reuse, clean energy generation, and community-oriented housing. Through continued stakeholder engagement and technical development, the city is laying the foundation for replicable, resilient building solutions across its districts.

Key Developments in Charleroi’s Refurbishment Solutions

• Building Renovation for High Energy Performance – Two industrial buildings, "Les Vestiaires" and "La Centrale", are undergoing complete refurbishment. The aim is to deliver future-ready buildings that anchor the new CleanTech District.
• District Heating Powered by Industrial Waste Heat – A new heating network is being designed to recover and distribute excess heat from nearby industries to buildings in the new district and the city.
• Energy Storage Deployment – Plans are underway to integrate hydrogen and electrical battery storage, ensuring stable and flexible energy use in the district.
• Multi-Actor Coordination – Key players include Igretec (coordination), the City of Charleroi, CleanTech District, private investors (Ceneo, Karno), and regional authorities providing funding and strategic support.

Next Steps

• Finalize the refurbishment plans for both buildings and begin permitting and construction phases.
• Complete site depollution and secure land acquisition.
• Develop and permit the district heating network, starting construction in 2027.
• Integrate storage and innovative energy technologies into the wider energy planning of the CleanTech District.

Lessons Learned

• Strategic Planning Anchors the District – The two building refurbishments are central to the district’s rollout. Delays in permitting, depollution, or land transfer impact the entire development timeline.
• Unlocking Industrial Synergies – Tapping into waste heat from nearby steel industries represents a major opportunity for sustainable urban heating but requires early engagement with energy producers and consumers.
• Funding and Business model – Securing subsidies and defining strong business model are critical early steps. Initial successes include funding approval for heat recovery and hydrogen initiatives.
• Future-Oriented Energy Integration – Coordinating refurbishment, heating, and storage strategies positions the CleanTech District as a replicable model for industrial area transformation.
   

Key Developments in Charleroi’s Refurbishment Solutions

• High-Efficiency Construction – New buildings in La Confluence are required to meet ambitious energy performance standards and integrate renewable energy systems.
• Urban Integration – The project combines housing, offices, public services, and shops within a socially diverse district, enhancing overall sustainability.
• Performance-Based Plot Sales – Real estate developers purchase serviced plots from SPL Lyon Confluence under the condition that buildings meet strict energy and environmental criteria.

Next Steps

• Commission the Super-Efficient Buildings.
• Monitor building energy performance via smart meters and the Building Operating System (BOS).
• Expand the use of renewable energy such as biomass and solar photovoltaic across additional developments.
• Support ongoing collaboration between SPL Lyon Confluence, developers, and municipal authorities to drive performance.

Lessons Learned

• Value-Driven Urban Planning – Selling land based on project quality (not only on price) encourages innovation and sustainability.
• Stakeholder Alignment – Effective coordination among developers, architects, and the public sector is key to delivering energy-efficient results.
• Cost Challenge – To be cost-efficient, environmental performance is integrated, right from the start of the project design with urban planning, architectural ambition, analysis of the construction costs and market demand, with a close collaboration between the urban developer, the real estate developpers and their experts and contractors, at each stage of the project development.
  
   

Key Developments in Charleroi’s Refurbishment Solutions

• Prefabricated Renovation System – Installation of pre-made façade and roof elements combining insulation, triple-glazed windows, PV panels, and – if required - ventilation systems.
• On-Site Renewable Energy Production – Integrated photovoltaic systems reduce reliance on fossil fuels and contribute to the building's renewable energy supply.
• Digital Building Modelling – Buildings are digitally scanned and converted into 3D models to manufacture customized prefabricated components.
• Targeted Use for Social Housing – Focused on upgrading aging residential buildings, particularly in the public housing sector, to improve efficiency and comfort.

Next Steps

• First project with prefabricated elements is under planning and construction works will start in 2026.
• Expand implementation across additional buildings in need of energy-efficient renovation

Lessons Learned

• Efficient On-Site Execution – Prefabrication is - under the right structural conditions- able to significantly reduce construction time and tenant disruption.
• Replicability – Suitable for a wide range of building types and sizes, supporting broad replication across urban areas.
• Economies of Scale – Larger-scale adoption leads to reduced production costs for prefabricated elements.
• Governance & Procurement – Specialized procurement processes are needed to engage qualified prefabrication contractors and align with funding criteria.

Key Developments in Charleroi’s Refurbishment Solutions

• Planning High-Energy Performance Buildings – Minimum energy envelope parameters and system efficiencies have been set to ensure the 90 buildings in Dolní Počernice reach Category A certification, in line with Czech energy regulations.
• Integrated Energy Balance Strategy – A basic concept for central heating and power supply has been developed, featuring a mix of heat pumps, PV, CHP to balance fossil use with renewables.
• Technical and Financial Coordination – Prague Development Company (PDS) and Prague City Hall are coordinating planning and validation, with Czech Technical University (CVUT) ensuring technical feasibility and alignment with the district’s Energy Master Plan.
• Tender Preparations Underway – Architect selection is planned to reflect performance targets and implement recommendations from the Energy Master Plan.
   

Next Steps

• Finalize architect selection and incorporate energy performance criteria into project specifications.
• Assess energy sources and finalize system design with a balance of flexibility, emissions reduction, and economic viability.
• Testing of other possible energy sources (solar thermal, hydrogen) and their contribution to hour-by-hour PCED positivity.
• Define the final technical specifications by the end of 2025 for both building and energy system planning.

Lessons Learned

• Set Clear Targets Early – Establishing energy performance goals and defining system efficiencies from the outset is essential to guide design decisions and ensure alignment across teams.
• There is large difference in results of carbon neutrality when evaluated on annual, monthly or hourly basis (with respected emissions factors).
• Innovation vs Feasibility – Hydrogen offers strong potential for achieving realistic hour-by-hour energy positivity in electricity supply, but high costs and insufficient seasonal heat supply pose ongoing challenges.
• Business Models May Conflict – Operator-driven economic models often diverge from PCED priorities, requiring deep alignment to ensure district-wide goals are met.
• Coordination Is Key – Cross-cutting solutions like this depend on ongoing collaboration between architects, engineers, planners, and operators to avoid silos and optimize outcomes.

Key Developments in Charleroi’s Refurbishment Solutions

• Energy Audits in Social Housing & Municipal Buildings – Over 100 audits being finalised across the city, gathering crucial data to calibrate the PCED digital twin.
• Smart Monitoring of Social Housing – Installation of Shelly smart meters underway in Lordelo Neighbourhood to map consumption patterns and assessment of energy poverty cases.
• Serralves Foundation Passive Building – The Álvaro Siza Wing of the museum, now open to the public, is built to passive standards, with future plans for renewable energy integration.
• Cross-Sector Collaboration – Strong coordination between AdEPorto, AEdP, Porto Digital, Domus Social and Fundação Serralves is enabling robust data collection, citizen outreach, and infrastructure upgrades.

Next Steps

• Finalize remaining audits and monitoring device installations in social housing units.
• Complete assessment of energy audit results and apply findings to digital twin calibration.
• Define a tailored Energy Poverty Index based on real household data.
• Support the installation of PV systems at the Serralves museum, pending funding.
• Advance integration of energy data into the city’s Urban Data Platform to ensure transparency and scalability.

Lessons Learned

• Standardization Enhances Quality – A common audit template helped ensure consistency and clarity in energy audits across varied housing types.
• Connectivity is crucial – Lack of reliable Wi-Fi in social housing delayed monitoring efforts, requiring creative solutions including temporary private network access.
• Public-Private Data Governance – Balancing data privacy with the need for open energy data remains a key challenge, especially with private institutions such as Serralves.
• Engagement Must Be Local – Gaining resident participation for audits and monitoring depends on accessible communication and support through trusted intermediaries like Domus Social.