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#4: Professorship for Sustainable Building

07/28/2022 |

By Birgit Baustädter

Alexander Passer holds the professorship for sustainable construction at TU Graz. In this interview he explains why life cycle analyses are so important and what goals he is pursuing with the professorship.

Alexander Passer lives for a sustainable building process. © Lunghammer - TU Graz

Talk Science to Me – the science podcast of TU Graz

Welcome and thank you for joining us again today. In today's episode we are also dealing with the big topic of sustainable building. Today's guest is Alexander Passer, who took over the professorship for sustainable building at TU Graz last year, but has already been working on this topic for many years.

Alexander Passer: My name is Alexander Passer. I was born in Innsbruck, came to Graz to study, graduated in civil engineering and then, following my master's degree, did a postgraduate degree in remediation management at Danube University Krems. Then I completed a doctorate on the topic of environmental assessment of buildings, was a visiting professor in Zurich in 2014 and since this year I have been a professor of sustainable construction in Graz.

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Talk Science to Me: Dear Alexander, thank you very much for being here today and answering my questions. We already know each other from several interviews, so I would like to be on a first name basis. I'd like to start with what exactly you are concerned with when it comes to sustainable building. What is it about for you? What is important to you?

Passer: The topic of sustainable building is a very complex one. Simplified, it is about two major topics: One is the so-called life cycle approach, where we not only look at the construction of buildings, but also at the entire life cycle, i.e. also the operation and the so-called end of the life cycle, i.e. the demolition of the building. And on the second, content-related track, it is about the topic of holism. That means not only ecology, but also costs and socio-cultural qualities, functional and technical qualities of buildings.

This holistic approach is becoming increasingly important. Why exactly? Why is it so important to not only look at the individual parts of the construction process or the building, but to look at it as a whole?

Passer: Yes, if we were to pick just one topic - let's take a topic that is very popular today: climate protection - we could end up shifting problems. In other words, we really want to look at this in all dimensions. It's about land consumption, it's about biodiversity, and it's also about issues like comfort, which is very important for the user, and that can be found in the social quality of buildings, for example.

What do you mean by comfort?

Passer: When it comes to comfort, there are the following issues: One is visual comfort, for example. The availability of daylight, as well as the so-called operative temperature - how warm and how cool is it in a building, are there draughts, how is the indoor air quality. In other words, a wealth of things that determine why a person feels comfortable or not in a building.

There are a lot of topics that play into this. Very many areas of research. How do you go about it as a researcher, as an individual or as a group of several people? Are there methods?

Passer: Of course, there are evaluation criteria for all of this. The principle we always try to convey is holism. This means that we need a complete set of criteria so that we have all the issues that play a role in sustainability on the table. And I have to be able to quantify each individual topic. Some can only be recorded qualitatively, but we mainly deal with those that we can measure or calculate. Those are the quantitative things. And then there are numerical values. An evidence, so to speak. And then you can set a benchmark. Then you can assess a building on the basis of a number of criteria, how well or badly it performs. That means that for 20 years there have also been building certification systems. You can think of it as a label. And then sometimes there are points or medals. And then I can see how good or bad my building performs.

How do I really have to imagine this in concrete terms? What do you do when you evaluate a building? Where does it start? Where does it end?

Passer: Classically, you start in the planning process. Very early in the project identification phase. Then there is usually a competition. There is a preliminary draft, a design. That is the whole planning process. Then at some point you start to construct the building. There is the whole issue of the construction process. Then there's the whole issue of operation. And then there's the disposal phase. In other words, we really try to think it through from beginning to end and also to accompany it.

Which specific buildings have you already done this with?

Passer: We were lucky enough to be involved in some so-called research and demonstration building projects. In Graz, for example, there is the Plus-Energy-Quarter in Reininghaus. A residential building combined with an office building. Then there is also the first plus-energy renovation in Kapfenberg, which we accompanied. Then there is, for example, the Med Campus of Med Uni Graz, which has also been certified for sustainability. And here you try to get involved very early in the planning process and simply make an initial assessment with the planning team and then also consider how the building can be improved and optimised. And then all the way to construction supervision. Then it's about topics like ecological building materials selection with regard to indoor air quality and all these things. It's a lot to think about and accompany.

If I now plan to build, plan, renovate, whatever - what can I do myself as a person?

Passer: We always refer to these as tools or instruments. For example, there is the instrument of building certification. The entry-level certificate, for example, is always "Climate Active". It started with single-family house builders - that is, it was very much about the topic of energy efficiency, but also others. And then you can build on that and use more and more complex instruments. There is, for example, the ÖGNB, the partner label of the DGNB, which really covers more than 100 criteria and is intended more for professional builders and not for single-family home builders, because it would be much too complex and also too expensive. Because, of course, such process support has to be worth something.

You already mentioned that it is also very much about the further use or demolition of buildings - how big is this topic? As I understand it, this is a relatively new topic that is being dealt with?

Passer: The European Commission has set six macro goals. One of them is the so-called circle economy. In other words, the circular economy. And of course, the construction industry is also part of this. On the one hand, there is of course the issue of excavated soil, which plays a major role in terms of quantity. But on the other hand, there is all the building rubble and construction waste. So the reuse of all these materials. That you don't just dump them, but really recycle them, reuse them. These are big issues. But because of the scarcity of raw materials, we have this issue in the whole value chain. This means that in the future, we have to look at buildings as raw material deposits of the future. And actually manage better with what is there. That is the goal of the European Commission.

We have now gone very deep into the subject. Maybe we'll go back one more time. A year ago you took over the professorship for sustainable building at TU Graz. What are the goals of your professorship?

Passer: The goals of the professorship are actually relatively simple. They are to support the economy in achieving the Paris climate goals. There are two major topics: One is the adaptability of existing buildings to the climate change that is already taking place. And the second is the so-called mitigation strategy. That means: How can we support the economy, the building industry, in the decabonisation of buildings. These are two major issues. And we want to position the professorship as a central contact point not only at TU Graz, but in Austria, and work out solutions together with industry.

Contact point for?

Passer: For the construction industry. This starts, so to speak, with the planners, through the building products industry to the executing trade. There are topics everywhere that affect us, so to speak.

This is not the first specialist position you have held. What have you done in this field so far?

Passer: I have a long experience that I bring with me. We have done a lot in teaching, of course. That means establishing new courses. For many years there has also been the postgraduate master's course in sustainable building, which we offer together with the Vienna University of Technology and which is also becoming increasingly popular. And then, of course, we have developed many methods on the one hand, but also accompanied the demonstration building projects. In other words, we have also been involved in the implementation, where we also learn where it is relevant for practice. And that's how the cycle closes.

You have already mentioned new courses. The next generation is a big concern for you in this topic?

Passer: From my point of view, it is the case that young people are demanding that the higher education landscape also develop new teaching content and teaching methods. And on the other hand, I always tell my students: You are the next generation of leaders. That means that you are the ones who enter the construction business and who can bring about changes in practice. That means you have to have all the skills to bring new ideas and innovations to the industry. These are also skills such as sustainability, climate protection, but also all the digital skills. These are simply topics that we have to impart to the next generation of managers.

If you think back now: Where did it start for you that you became so interested in the topic of sustainable building?

Passer: That was, so to speak, within the framework of my postgraduate studies, which I did, where it was already said at the time: the renovation of buildings is becoming increasingly important. That was 20 years ago. It is actually a pity that the topic is still high on the list of priorities, but implementation is lacking. And actually, through years of activity, awareness of the importance of climate change and for the environment has increased. The evidence has also increased greatly in this area. This means that it simply requires much faster action, and in the meantime this topic has also become widely accepted. Unfortunately, there is still a lack of implementation of this topic, so to speak.

And what exactly attracts you to the topic?

Passer: So in my opinion, you can't really say "attract". I actually see more the necessity. That is, it is more of an imperative to research the topic. On the one hand, but also, of course, to demand implementation. And as long as I see that there are still people who say on the one hand that climate change is only a temporary phenomenon, that sustainability is a soft skill and other things, I see a great need for awareness-raising on the one hand, but that we also offer the appropriate tools to support implementation, so to speak.

What do you think needs to change in order to make the building industry more sustainable?

Passer: Yes, in order for it to change, the appropriate framework conditions are needed on the one hand. There are now also some initiatives at the European level, the taxonomy is now on everyone's lips due to energy sources. This should be applied to all sectors of the economy. That means, of course, that it is about the issue of financing, but on our side, so to speak, it is more about raising awareness. It's about the issue of transparency. I have already mentioned the building certification system. It is like a sticker. We all know the energy certificate. But it only refers to energy. But it should be extended to include, for example, the grey greenhouse gas emissions. This means that transparency is needed on the one hand. That is a very important issue. Then you have the evidence, so to speak - what weighs, what has, how good or bad a building performes. And on the other hand, if awareness increases, I also hope that the market will change accordingly. That means that consumers will perhaps be prepared to support more sustainable building methods or a more sustainable lifestyle and perhaps also finance them accordingly. Many things pay off in a few years, but the construction costs in particular are usually a bit more expensive. But we know that a PV system pays for itself within a few years in terms of energy, but also in terms of costs. And it's the same with sustainable buildings.

This means that here again, looking at the entire life cycle is so important.

Passer: That's why it's so important to look at the entire life cycle. That you look a little ahead, think about how a building will change. This is a very important topic, especially with regard to climate change. We actually always say that buildings have to be ready for 2050. That means I have to construct a building now in a way that it will properly withstand the climate in 2050 or 2100. Because otherwise I will simply have to adapt the building again in 20 or 30 years. That means additional costs again. That's actually insane, especially when you already know today how the climate can change in the scenarios.

You mentioned it earlier: grey emissions. What is that exactly?

Passer: This is also based on the concept of grey energy. If you like, the Swiss once invented it as a term. At least in German. In English, it's embodied energy or embodied emissions. That's what it's all about: a German colleague described it as embodied greenhouse gas emissions. That is, to quantify the greenhouse gas emissions that arise during the production of products. We no longer see them, that's why they are embodied. But they are inside every product. And we usually know our energy consumption and perhaps also the fuel consumption of a car. Some people also know the CO2 emissions during operation. But in the products, of course, it is difficult and more complex methods are needed. I have to look at the entire value chain. That means from raw material extraction to transport to the factories, the production process. And there are now also labels: so-called environmental product declarations. You can think of it as a sticker on a building product, so to speak, where it says at the top how many kilograms of CO2, but also other environmental impacts, are caused by such a product.

Why are these grey greenhouse gas emissions so important?

Passer: In my view, the grey greenhouse gas emissions are so important because they are usually neglected in the balance sheet. In Austria we have about 80 million tonnes of greenhouse gas emissions and if we were to add the grey greenhouse gas emissions from the products, then about 50 percent would be added. This is the so-called consumption-based accounting. This means that we can no longer complain about other countries that have such high greenhouse gas emissions. Instead, because we purchase the consumer goods, i.e. pay for them - they are produced elsewhere for us - we have to account for them according to the polluter pays principle. And that amounts to 120 million tonnes. This means that the greenhouse gas emissions we cause are much greater than is commonly known. And in my opinion, this corresponds to the need for action according to the polluter pays principle. We simply have to become more active and think about how we have to change our consumption. That means procuring other products so that we can reduce this overall balance.

When I think of building in 2050, what do I have to take into account? Can you explain that a little bit?

Passer: The IPCC, the international body, publishes the assessment reports on climate change. And there are scenarios on how the world climate will change. It deals with issues such as temperature, of course, which is very much in the public's consciousness, but also with heavy rainfall, wind, etc. In other words, all the weather caprices, as they are called in the media. The frequency and intensity of all these things is increasing. This means that if I now know how things are changing, then I have to react accordingly in my planning. And simply change my requirements for the building, so to speak. This means that the demand for heating, as a terminus technicus, will tend to decrease. That means the winters will get warmer. But in return, the summers will become hotter and hotter. They will not only become hotter in temperature, but also in duration. That means there will be a greater number of tropical days, which will also be on several days in a row - up to two weeks. This simply means that it will hardly be possible to cool and naturally ventilate the buildings as they are currently constructed. Accordingly, it is very important to take precautionary measures, such as shading the buildings, etc.. And if possible, when constructing new buildings, this cooling requirement should also be taken into account. These are things that, I would say, are actually already part of the state of the art, but are not yet often demanded in practice. And then it is simply a pity because I then have to adapt the buildings again later. And in my opinion, that is absolutely avoidable. This involves costs and, of course, greenhouse gas emissions. That is actually all avoidable.

Are there several factors that you take into account other than the weather and the climate?

Passer:  Another topic, but this does not only concern climate change, but sustainability, is the whole topic of functionality. That is to say, how can I perhaps repurpose a building? How can I convert it? There are also criteria for this, for example. And when a building has reached the end of its useful life, it is essential to know whether it can be dismantled. Can I reuse the materials? Can I dismantle it well? So there are many aspects that also play a role.

Are you talking about public buildings, private buildings, both?

Passer: I always see the public sector as a role model. And you can also see that in various directives, where, for example, in the revision of the Energy Performance of Buildings Directive, new buildings must be zero-emission buildings from 2030, and public buildings from 2027. And public buildings will have to be zero-emission by 2027, which also shows the role model function of the public sector. A very big topic - because of course quantity plays a role - is of course residential buildings, which dominate new construction activity, but also the building stock. And there it is divided between private owners and, so to speak, rental properties - that is also a little different from east to west. But yes, that's how it's divided. That means that residential buildings also play a big role.

Is it primarily about new buildings?

Passer: No. I have already mentioned the topic of renovation. If you look at Austria's greenhouse gas emissions in terms of size and distribution, the existing buildings naturally play the biggest role. This means that Austria is essentially already built - from the infrastructure to the buildings. This means that the topic of renovation has now also gained momentum due to the changed geopolitical situation, if you want to put it that way. That is very important. That means that the topic there is: getting out of fossil fuels. But only in combination with the best possible thermal renovation. This is also a demand that the Austrian Climate Councils, i.e. the Citizens' Council of Austria, has called for, a rapid, uncomplicated, unbureaucratic renovation offensive. That would be very important. It would be very important to reduce the energy demand as much as possible and then cover the remaining demand with renewable energy sources. For me, that is the credo of the hour, so to speak.

You have already mentioned it: In addition to your professorship, you are also involved in a number of committees that promote sustainability in the building industry and climate protection. For example, in the Climate Council of the Federal Government or the Climate Change Center Austria. How important are such bodies and what do you do there?

Passer: Yes, maybe we start with the CCCA. This is the network of the Austrian climate research community. So from climate researchers to the topic of construction. So it really covers a wide range. I am a member of the board, deputy chairman. What is it about? It's about really covering the topic in a broad way. Climate change not only affects residential buildings, but also the whole issue of infrastructure. That means roads, alpine areas, etc., as well as the risk of debris flows. mudslides. In other words, we are facing a whole host of challenges. And also how nature reacts to it. This means that we are also dealing with the topic of forests and agriculture. In other words, it is really extremely broad. And there, if you like, I am a small part of a larger network, so to speak. But we all learn from each other. And of course the CCCA contributes to the writing of this report on the state of affairs in Austria. Right now, 120 scientists are working on the next assessment report, which, hopefully, will be published in two years. It will then serve very much as a basis for policy, simply to present the scientific facts. That means that you can really point out that this is considered certain, that this is the evidence on the subject of climate change. And that is also the motivation to collect the facts, so to speak, but also to raise awareness again on the other hand, in order to simply support Austria there as well. And the topic of "supporting Austria" is also a role that I have been able to take on in the last six months: I have been active in the scientific advisory board of the Austrian Climate Council and was in charge of the field of housing needs together with my colleague Andrea Jany from the University of Graz. And we simply supported the citizens with facts in their decision-making. And we discussed with them where measures might be scientifically sensible and appropriate. As scientific advice.

And also at TU Graz there is now the Sustainability Advisory Board, which you chair.

Passer: Yes. The Sustainability Advisory Board was established by the Rectorate. Its purpose is to advise the rectorate on important and strategic questions regarding sustainability. This means that we are a group, a committee that is really made up of all the faculties on the one hand, but also of all the OUs - these are the organisational units here from the vice rectorates but also from the service institutions. That means a very broad range of expertise. And we simply develop proposals, ideas, so to speak, on how TU Graz must change in the area of sustainability or what simply needs to be done. And one of the strategies is, for example, this climate neutrality strategy, which has also been adopted, where TU Graz was the first university to declare that we want to become climate neutral by 2030.

What exactly is planned there?

Passer: A bundle of measures is being implemented in this climate neutrality strategy. This means that in 2017 we drew up the first greenhouse gas balance sheet and established the facts for Graz University of Technology. This begins, so to speak, with energy consumption in the buildings for heating and cooling, but also for electricity. On the other hand, the topic of business trips, mobility, commuting - all these things - is also very important. But then there is also the issue of procurement. Where do we buy? How many computers and how many tonnes of paper do we buy? All the way to the topic of canteens. If you look at all the emissions caused by TU Graz, then you can develop strategies, so to speak, which are laid down in this climate neutrality strategy. That means, of course, that we have to invest money in order to reduce greenhouse gas emissions. One of the measures that is already being implemented is, for example, the whole area of mobility. We are promoting a public network card, and there is the TU Graz bicycle. In the same way, we are now procuring more environmentally friendly electricity. There is simply a wealth of measures that we will be implementing in the next few years.

And there is now also the new Center of Sustainable Construction at TU Graz.

Passer: This is a new format from the rectorate. It is intended to establish long-term research topics at TU Graz. And as we already discussed at the beginning of the interview, the topic of sustainability is very complex. And that's why I'm pleased that many colleagues from different faculties have come together, so to speak, to become more active in implementing the topic, to bundle competences. We have done this by defining five strategic fields of action. And in these, we simply try to work together, interdisciplinary, transdisciplinary, across faculties, to initiate new projects. And accordingly, to support the topic not only in research, but also in implementation, concentrated, with combined forces, you could say.

This means that we are back to the overarching view - including all disciplines,...

Passer: Exactly. Here, too, it's about using synergies in the building. That means that civil engineers, architects, mechanical engineers and electrical engineers are working very closely together in order to be able to better advance the topic together. Because in some cases the speed of implementation is simply too slow. That means there is a great need and we can only achieve this by joining forces.

We have already talked a lot about what is being done. Maybe you could briefly summarise what the current challenges are that we are facing.

Passer: On the one hand, we have known about the global challenges for a long time: that we have to get out of fossil fuels. This has been known for decades. The current geopolitical situation is intensifying the pressure, so to speak - but now rather economically and not necessarily in terms of environmental policy. These are actually favourable conditions for initiating the necessary transformation there. Of course, we are now seeing the whole issue of raw material supply, somewhat as a result of the Corona pandemic, but also of the new situation. This means that the construction industry is also a very raw material-intensive sector. We see this not only in building materials such as wood, which is harder to come by, but also steel and mineral building materials. This is simply a challenge that we have to face. That means this transformation back towards the local, regional economy. This is simply a topic that is now gaining in importance because of the necessity. And the second important issue is how we can move more towards energy self-sufficiency, i.e. renewable energy sources, also regionally. These are topics that are now suddenly very relevant economically due to the changed geopolitical situation.

How do you assess the readiness of society and the economy to face and tackle these challenges?

Passer: It's interesting that when you look at this topic at the research level, there are not only the CEOs for Future - it's something similar to the children who have the Fridays for Future. In other words, the awareness is now visible and also the willingness. Especially in the Austrian construction industry, there are hardly any companies left that don't have a Roadmap 2030. It's similar to what TU Graz has for climate neutrality. That means they know about the necessity. Due to the legal framework conditions, the thumbscrew is also being tightened more and more. This means that those who are already beginning to develop strategies with foresight are in a good position. There are always frontrunners and a few stragglers. But I see a lot of things changing. And as I said, at the moment we are "lucky", if you like, economically it is of course a disadvantage that we have a tailwind, that the economic need is increasing very strongly and therefore the companies are of course working much more intensively on these strategies in order to ultimately free themselves from the supply bottleneck, so to speak.

In research, money always plays a role, among other things. If that were not an issue at all in this case and you had all the possibilities - what would you want to implement?

Passer: Yes, if money did not play a role, then we could really act sustainably. In the sense that we don't leave any legacy to future generations. In other words, we could really think about valuing nature more and then change production methods accordingly - but that also applies to consumer goods. I'm talking about organic farming and the like, which is economically uninteresting today because labour is so expensive due to the intensity of the work, so we could of course consider creating a bit of a shift. And accordingly give nature back the position and role that it actually needs. Because the important thing is that if we destroy nature, we ultimately deprive ourselves of the basis of life. In other words, it is not the economy that is our basis, but nature. A certain rethinking is needed, and that's why I think that if money didn't play a role, we could turn things around a bit.

How do you personally integrate this into your life? How do you live,  how do you work?

Passer: I work at the TU Graz. At the moment we are lucky enough to be in an almost zero-energy building in the so-called Science Tower, which is supplied by deep geothermal energy for heating and cooling. That means it's actually a very good building in terms of its energy balance. I live in house  which is also over 100 years old. That's basically good, too. It is connected to the district heating system, which is not so good because in Graz it is still largely supplied with fossil fuels. But that affects us just as much as TU Graz. It is difficult to bring about changes there. Of course, you can only try to speak out loud or to urge, but in reality we are a bit dependent on good will. And privately: I actually only cycle to work. Like TU Graz, we have been buying environmentally certified electricity for a long time. It has one twentieth of the emissions of an average Austrian electricity. And there are just a lot of things, ending with the topic of mobility. This is now also anchored at TU Graz through the advisory board. I make sure that I only use the train for business trips. Or, if there is no other way, I use the e-cars from TU Graz. So there are actually a lot of seemingly small things that add up to quite a lot when you take them into account.

Thank you very much for the interview today!

Passer: Thank you! You're welcome!

Thank you for being here and listen again next time!