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Zero-emission buildings: The path to net zero demands structural change

May 2, 2023

By Solangel Minotta

Buildings are an area of significant untapped potential when it comes to energy efficiency (Photo © Getty Images)

Find out what the building industry is doing to increase energy efficiency in this Q&A with Anita Derjanecz, Managing Director of the Federation of European HVAC Engineers (REHVA)

As a professional association, the Federation of European HVAC Engineers (REHVA) has a mission to educate and train professionals, transfer knowledge between academia and industry, and promote innovation and European engineering practice. This includes offering knowledge services around the critical topic of net zero.

REHVA supports the standardization of engineering practice and knowledge exchange across borders in Europe, and this work is now targeted on issues related to zero emission buildings. The organization is dedicated to working on this effort with its network of national member associations and other stakeholders and believes that an all-hands-on-deck approach is needed to deliver a decarbonized built environment.

Recently, I interviewed REHVA’s managing director, Anita Derjaneczopens in new tab/window. The interview has been edited slightly for length and clarity.

Anita Derjanecz

Anita Derjanecz

Societies & Sustainability

This article is part of our ongoing series of interviews with engineering society leaders about their perspectives on how engineers are forging a critical path forward toward achieving net zero.

How is REHVA working toward the goal of achieving net zero?

We pursue the vision of providing healthy indoor climate in all buildings and communities the most energy-efficient way. In line with the Paris Agreementopens in new tab/window, we support the implementation and development of the EU energy and climate policies aiming to transform buildings to zero energy performance and zero carbon emission levels.

In the building sector, we must first achieve a zero energy performance level by a massive decrease of energy demand, called the ‘energy efficiency first principle.’ Once this is achieved, the remaining low energy demand should be covered by clean energy sources to reach zero emission.

What is REHVA doing to help its members navigate the path to net zero?

REHVA helps its members and the building professional community by knowledge sharing, education and technical guidance promoting high-quality engineering science and practice. Our guidebooks on the Knovel platform are one example of this. We also publish a technical journal, organize courses at national and EU level, advocate European policy development and contribute to the standardization work in our field.

What critical preparation is needed for engineers to be successful in achieving net zero?

Building services engineers and HVAC designers need new skills to design, construct and operate highly efficient and healthy buildings. We must not forget the main objective: buildings are built for people, and our profession must ensure the best indoor climate quality for health and productivity. Therefore, our mission is to achieve healthy buildings at the most energy efficient and low-carbon way.

We have European standards to ensure system performance that take indoor environmental quality (IEQ) into account. The whole regulatory environment is changing. Design engineers must be aware and follow these changes.

Then there are overarching technological developments, for example, digitalization. Engineers need to embrace ICT, BIMopens in new tab/window and data science. Improving the related skills is inevitable for optimized system design and operation and for the digital transformation of the construction process value chain ahead us. This brings a different way of collaboration between stakeholders along the building lifecycle.

How is the work of your engineers helping to create a greener and more sustainable world?

HVAC systems are responsible for a large share of total energy use and CO2 emission of buildings, so naturally engineers have a key role to play in cutting emissions in the sector. Building services engineers focus on improving system performance. No matter how efficient a component is, if they fail to work efficiently, the whole building as a system remains inefficient. Europe has advanced system performance standards; some of them also became global ISO standards.

Ensuring high system performance levels in use by adequate design, ongoing commissioning and operation is the often unnoticed but major contribution of building services engineers for a greener world. This gains even more importance when we come to the decarbonation of the energy supply side. Grid flexibility and demand control flexibility are problems to be solved by engineers to balance energy use and handle peak demand due to electrification.

Finally, we need new or improved energy efficiency and renewable energy technologies, and research engineers are developing these sustainable building technologies to bring prices down and deliver innovative low-carbon solutions.

Which obstacles to achieving net zero are your members most focused on?

We cannot forget that we have war in Europe, where the aggressor uses fossil energy supply as a weapon. The building sector is in the center of the current turmoil, as the natural gas imported from Russia is needed to heat a largely inefficient building stock. For the next winter, Europe most probably won’t be able to secure enough natural gas. The only solution is to phase out fossil fuels from heating as fast as possible.

The REPowerEUopens in new tab/window plan announced the massive deployment of heat pumps. However, there is no silver-bullet technology solution. Our members are now concerned with providing independent and comprehensive technical guidance on how to shift from natural gas in buildings at a very fast pace. We’ll soon release a report on the “replacement of gas boilers with heat pumps, district heating and hybrid solutions,” and later we’ll publish a new guidebook on engineering practice and applicable concepts on building decarbonization for HVAC professionals.

Another obstacle is that the EU is not a federal state, so despite the EU policies, national legislation and practice differs. Imagine that you have 27 different building codes, energy performance calculation methods or product standards in Europe. This is not good for the common market — neither for global HVAC companies nor engineering consultancies that operate across borders. REHVA works on the harmonization of standards and engineering practice to address this obstacle.

What are some notable achievements that you think are moving us closer to net zero?

The set of European building performance standards, developed on a mandate of the EU’s Energy Performance of Buildings Directive (EPBD)opens in new tab/window, is a great instrument to achieve zero energy buildings and cut emissions. REHVA is investing its resources in developing a training and certification scheme to promote the uptake of these standards by professionals. The EPBD is now under revision to boost energy efficient renovation and shift from zero energy to zero emission requirements. Overall, the goals and policies of the EU Green Deal are progressive, but we must bring these to the practical level and work with practitioners and industry to deliver on these policies.

Where do you see the most potential for net zero related change in the next few years?

The huge untapped potential in increasing the energy efficiency of existing buildings is key. The building sector has been a cornerstone of the EU Green Deal from the beginning, but the current energy crisis will speed up energy-efficient building renovation and the phase-out of fossil fuels in the next couple of years.

On the other hand, many HVAC manufacturers in Europe take action to decarbonize both their production processes and their products following a whole-life-carbon approach. They pledge, for example, to release LCA product declarations for all their products. The EU F-gas regulationopens in new tab/window set an ambitious timeline for the phase-out of refrigerants with high GWP with a mandatory EU-level product declaration database in place. The circularity approach also gains more and more attention. I am confident that within five years, even more companies will follow suit.

Anita Derjanecz

Anita Derjaneczopens in new tab/window is Managing director of the Federation of European HVAC Engineers (REHVA)opens in new tab/window and has been working in the field of building technologies for 10 years. She is a sustainability and climate action advocate, passionate about a sustainable and just world in ecological, economical and societal terms. Her professional mission is to advocate the importance of indoor climate quality, to support transdisciplinary cooperation and knowledge exchange for high performing healthy buildings and for a decarbonized built environment.

Solangel Minotta

Solangel Minotta serves as the Director of Strategic Partnerships & Publisher Relations for Elsevier, overseeing a portfolio of over 150 content partners for Elsevier's Engineering Solutions team. She is dedicated to working collaboratively with her partners to generate thought-leadership content aimed at supporting various routes towards achieving net zero. With a passion for cross-functional teamwork and relationship building, she is optimistic about our future.


Solangel Minotta


Solangel Minotta

Director of Strategic Partnerships & Publisher Relations