HVAC in Zero Emission Buildings: REHVA Brussels Summit 2025 at the Heart of EU Policymaking

General overview

The 2025 REHVA Brussels Summit took place at a moment when the European building sector is transitioning decisively from rule-making to implementation. With the revised Energy Performance of Buildings Directive (EPBD) entering its delivery phase and the Commission’s guidance package published at the end of June 2025, attention has shifted from negotiating provisions to making them work on the ground.

This year’s edition carried strong symbolic weight. The second day of the Summit – the policy conference – was hosted at the European Economic and Social Committee (EESC) in Brussels under the title “HVAC in Zero Emission Buildings – solutions for IEQ and affordable buildings.” This was more than a venue choice: it marked the first time REHVA organised its Summit in formal partnership with an EU body, reflecting its increasing visibility as a bridge between technical expertise, market actors and institutions.

The EESC serves as the EU’s consultative assembly for organised civil society. With 329 members representing employers, workers and various civil society organisations, it provides opinions to the Parliament, Council and Commission on legislative initiatives. Thomas Kattnig, Vice-President of the EESC’s TEN Section (Transport, Energy, Infrastructure and Information Society), highlighted this institutional role in his opening speech, describing the Summit as a unique moment where scientific knowledge, industrial experience and the organised voice of civil society converge. Hosting the event within the TEN Section underscored the close relationship between building regulation, energy policy, and broader societal goals.

The structure of the programme mirrored this ambition. The conference was organised into three thematic sessions dedicated respectively to indoor environmental quality (IEQ) and decarbonisation, building affordability and energy poverty, and renovation financing. Each session blended institutional perspectives, technical analysis and interactive panel exchanges designed to test the feasibility of EPBD implementation against practical realities.

Looking back: consolidating a decade of Brussels Summits

The 2024 edition marked the tenth anniversary of the Brussels Summit. Over the past decade, the event has evolved from an internal REHVA gathering into a recognised platform where engineers, researchers, manufacturers, building owners and policymakers can discuss the evolution of EU building policies. The 2025 edition built on this trajectory, but with a deeper institutional partnership and a clearer focus on post-adoption implementation challenges.

Moving the second day into the EESC and forming an explicit institutional partnership represents a logical progression: REHVA is no longer only monitoring policy developments from the outside but actively shaping the dialogue around them together with EU bodies and civil society actors.

Day one: committees, strategy and community

The first day, held at the Maison des Associations Internationales, was dedicated to REHVA’s internal bodies. Meetings of the Education and Training Committee, Publishing and Marketing Committee, Technology and Research Committee and the Supporters Committee filled the agenda. Although operational and internally focused, these meetings reinforced themes that would emerge prominently on day two.

Coffee breaks and the REHVA Dinner served as informal networking moments, reinforcing the sense of community that underpins REHVA’s activities.

Day two: policy conference at the EESC

The second day shifted to the EESC, where the policy conference brought together institutional representatives, researchers, industry professionals and civil society organisations for a full day of dialogue. The agenda was well-defined and centred around three sessions, each addressing a different dimension of EPBD implementation.

Welcome and opening: a political framing for a technical community

REHVA President Prof. Livio Mazzarella opened the conference by emphasising the dual objective of the Summit: identifying HVAC solutions that can deliver both IEQ and affordability in zero-emission buildings. He thanked the EESC for hosting what he described as a milestone partnership for REHVA.

Thomas Kattnig from the EESC then provided a broader political context. Speaking both as an institutional representative and a trade unionist, he warned that the Green Deal’s ambitions are under strain in today’s volatile environment. He cautioned against retreating from climate commitments and underlined the need to reinforce the skills base and ensure social fairness. He argued for the importance of allowing Member States sufficient fiscal flexibility to invest in affordable and social housing, stressing that renovation must not be framed as a burden, but as a strategic investment in well-being and competitiveness.

This framing set the stage for the three sessions that followed.

Session I – IEQ and decarbonisation: achieving both goals with one legislation

The first session explored one of the EPBD recast’s core ambitions: to advance decarbonisation while ensuring healthier indoor environments. This session consisted of three keynotes and an interactive panel.

Niels Ladefoged, Deputy Head of Unit b.3 (Buildings & Products) at DG ENER opened with a comprehensive overview of the building sector’s challenges. He recalled that buildings remain responsible for a large share of Europe’s energy consumption and gas use, while most of the EU building stock performs poorly. Many Europeans still live in unhealthy indoor environments or face difficulties keeping their homes adequately warm. In this context, EPBD implementation offers an opportunity to simultaneously tackle emissions, improve living conditions and increase energy security.

Ladefoged presented the EPBD guidance package, which includes practical direction for implementing minimum energy performance standards, IEQ requirements, inspections and digital data systems. He stressed that the purpose of the guidance is not to create administrative burdens, but to provide pragmatic tools for national authorities.

MEP Jutta Paulus, speaking via video, reinforced the triple nature of the EPBD as climate, health and social legislation. She warned against political attempts to weaken the Green Deal and insisted that renovations must be accompanied by financial support to avoid exacerbating social inequalities.

Jarek Kurnitski then presented REHVA’s proposals for implementing IEQ requirements, organised around the need for clear design standards, robust verification mechanisms and cost-effective solutions. He emphasised that IEQ improvements and decarbonisation can reinforce each other if approached systematically.

The panel discussion brought these themes to life with perspectives from the Commission, REHVA, eu.bac and Saint-Gobain. Exchanges with the audience touched on the need to simplify complex systems, the importance of updating standards to reflect new system behaviours, and the risk of communicating EPBD requirements in ways that create resistance. Several interventions highlighted persistent issues in the handover and commissioning phases of buildings, where performance gaps often emerge.

The session concluded with a shared view that IEQ and decarbonisation are compatible objectives, but require careful calibration of technical, regulatory and practical elements to ensure that implementation is effective and politically sustainable.

Session II – Addressing building affordability and energy poverty

The second session shifted focus to the social dimension of renovation. Johann Zirngibl opened by noting that the EPBD is increasingly evaluated not only on its environmental outcomes but also on its impact on housing affordability and vulnerability.

Stefan Moser, Coordinator of the European Commission Special Taskforce on Housing Crisis in Europe,  provided a sharp diagnosis of Europe’s housing challenges: rising costs, insufficient supply, energy price volatility and persistent energy poverty. He argued that while the EPBD is not the source of the crisis, it can alleviate pressures if implemented thoughtfully. Renovations must be socially fair, which requires grants, subsidised loans, guarantees and accessible technical assistance. Member States should use the flexibility within the EPBD to plan realistic renovation pathways, targeted and context-specific.

The joint intervention by Zirngibl and Jana Bendzalova added an engineering and performance-based angle. Poor ventilation, inadequate insulation and inefficient systems often drive energy poverty. Well-designed renovations can therefore reduce bills and improve health at the same time. But this depends on proper design, commissioning and verification, as well as transparent data and digital tools.

The panel discussion in this session was one of the day’s most dynamic segments. Questions from the audience probed how renovation support can reach vulnerable households, how rising construction costs affect planning, and how data can be used for performance verification. Panellists consistently highlighted the need to avoid framing the EPBD as a threat to affordability: the real threat lies in maintaining a status quo of low-quality buildings, high bills and unequal access to efficient technologies.

Session III – From data to deal: unlocking financing for renovation

The final session turned to the financial architecture underpinning renovation. Frank Hovorka opened by stressing that technical solutions and regulatory frameworks are necessary but insufficient: without scalable financing models, renovation will not accelerate.

The ENERGATE marketplace presentation by Katerina Papapostolou and Ioanna Andreoulaki illustrated how digital tools can support renovation financing. By harmonising data and standardising documentation, ENERGATE aims to connect building owners, technical providers and financial institutions. Clear performance indicators and comparable scenarios help reduce investor uncertainty and build trust.

The final panel brought together representatives from BELIMO, the European Savings and Retail Banking Group, Energy Efficiency for Europe and the digital company COMMUTY. The discussion illuminated four complementary perspectives:

1.    manufacturers emphasised the need for measurable performance to justify financing;

2.    bankers highlighted the importance of standardised and reliable data;

3.    NGOs called for integrating non-energy benefits such as comfort and health into valuation models;

4.    Digital innovators underlined the importance of user behaviour and occupancy data.

Audience questions focused on persuasion strategies for financial institutions, ways to simplify procedures for SMEs and the potential for performance-based service models. The consensus was that standardisation, simplified documentation and better alignment between EU legislation and national financing schemes are the most urgent levers for progress.

Professor Mazzarella concluded by noting that indoor environmental quality, decarbonisation, affordability and financing are not distinct challenges but parts of a single integrated transition. He thanked the EESC for the partnership and reaffirmed REHVA’s commitment to supporting EPBD implementation through technical guidance, knowledge exchange and stakeholder engagement.

Concluding reflections

The 2025 REHVA Brussels Summit marked an evolution in REHVA’s role in EU policymaking. The partnership with the EESC symbolised the growing recognition of REHVA as an authoritative voice linking engineering expertise with EU-level governance.

Across two days, the Summit showcased how a technical community can prepare itself internally – through committees, research networks and supporters – and then engage constructively with EU institutions and civil society. It demonstrated how the success of the EPBD depends as much on skills, governance, data and financing as on legislative text.

Indoor environmental quality, social fairness and renovation financing emerged not as peripheral themes but as central components of Europe’s building transition. The Summit helped align engineers, policymakers, civil society and financiers around a shared understanding of what Europe must do next to deliver buildings that are simultaneously zero-emission, healthy and affordable.