Anja Koller: Mr Philipp, you gave a TED Talk, saying that sustainability is not about sacrifice. What is it about?

Dominik Philipp: The question at the beginning of every action is: „Why do we do what we do?“ The answer is simple: „Because we have needs.“ People act for emotional reasons 80 per cent of the time and then try to justify their actions, rationally. It is thus easier for us to satisfy our needs than motivating ourselves to solve problems or do without things. We should therefore get out of the „problem-solving or sacrifice“ mode when we talk about sustainability in the construction industry. We automatically act sustainably if we address our needs, because we don't feel the need to fail on climate crisis.

We often hear that architects need to know today what the needs of tomorrow will be. How do you know what the users of a building or open space will need in the future?

DP: Let's take Munich Central Station as an example. The competition was decided in 2006, construction is currently underway and will probably not be finished before 2030. Back then, when Auer Weber submitted their design, they were designing a building that needed to be up-to-date at some point in the future. This is a major challenge. We don't know the needs of tomorrow. What we do know is that needs change over time. We therefore have to design buildings able to adapt to changing needs, able to be updated like the apps on a smart phone.

AK: How do we do that?

DP: We need to equip buildings with two types of flexibility: firstly, flexibility of use - constructing buildings so that they can be used for different purposes. Secondly - when the flexibility of use is exhausted - we need flexibility of construction, which means being able to break the building down into its components. This scenario does not know waste or rubbish as the built environment becomes our material store and our resource.

At Dietrich Untertrifaller, we are working intensively on digitalisation in timber construction. We want to construct buildings easy to be adapted and assembled from individual components. These components can then be dismantled and assembled into new, modified objects according to our needs. But if we want to use individual components and make the building recyclable, the realised building must fully match its virtual model.

AK: This is not yet the case…

DP: We, or rather the construction industry as a whole, are heading into the right direction. Our buildings in use change over time; at some point it will need modernisation. These changes mean, it will no longer fully match its digital twin. There is currently a cut in the digitalisation process. You have to remeasure the real building in order to update its digital twin. In the future, the connection between the virtual and the real building must remain intact, both must be synchronised and communicate with each other so that we can optimise its life cycle assessment and flexibility.

The good news is that the days of implementation on a voluntary basis are over. Politicians are setting new framework conditions. Ursula von der Leyen's major ‘European Green Deal’ project is what we need to for a reorientation - in economy and society. EU taxonomy, ESG guidelines,… -  all of this is forcing planners and builders to plan and build differently.

AK: And with that…

DP: ... more interconnected. It's good to know the materials we used for a 100 houses we've built. But if nobody else knows about it, it's no good at all. Digitalisation and networking are prerequisites for a construction process that saves resources, includes dismantling, is circular and is orientated towards our society’s needs. Companies like Madaster and Concular deal with the cataloguing and digitalisation of materials, thus already working towards this process. If we design our buildings while recording all data, cataloging all components with high precision, we will be able to use this database in 20 years' time and retrieve all information making the installed components available elsewhere if necessary. So once this circular thinking works for a building, it will work for a neighbourhood and an entire city as well.

This networking also applies to energy. We can collaborate and form energy communities. A photovoltaic system on a single house may not be enough for its energy supply. But five houses in a community may. We can equip neighbourhoods to make them completely or at least partially self-sufficient. Many architectural projects still only consider the limits of their own site. We need to widen our perspective.

AK: Networking, collaboration is actually part of the DNA of architects.

DP: That is true. But at the moment, the planners on the other side of the road working on a refurbishment project for over a year not telling anyone about it. And I'm doing exactly the same thing on the otter side. The team across the street puts out a tender and looks for suitable companies. I do the same. We both need scaffolding and a crane. So far, we've done everything separately because we don't know about each other's activities and requirements. We commission two separate companies, transporting two separate scaffolds with two separate lorries. However, if we both communicated and networked, the result would be a larger service package, thus saving resources. We would only need one scaffolder, driving into town once, erecting scaffolding at my place and at my neighbour's. In the best case scenario, we would also share the scaffolding if a time shift allows.

AK: We would reduce mobility and, as you say, save resources.

DP: And not only that. We would also have enormous economic advantages. We would have larger service packages, better offers. Companies could plan more efficiently.

AK: The economic advantages are obvious. What is preventing us from taking action more quickly?

DP: Our experience. We have spent years learning to do things the way we do now. Our construction sites today still look like they did when my parents were working as architects 30 or 40 years ago. Breaking with this behaviour is a big challenge, but also an opportunity for young architects. After all, it is the young generation asking uncomfortable questions to which there are often no answers but the typical  ‘We've always done it this way’.

AK: Modern timber construction could provide different answers. Dietrich Untertrifaller see themselves as a pioneers in this field. One current project is the TU Munich campus in the Olympic Park. In your TED Talk, you argue that modern timber construction is predestined for flexible and recyclable construction, networked and oriented toward our needs. Why is that?

DP: Wood is sustainable, but no panacea. It is clear that it is renewable and an excellent CO2 storage once it reaches a certain age. However, a special characteristic of wood as a building material is its precision, to millimeter range. This precision cannot be achieved with concrete. The same goes for the flexibility, separability and dismantlability.  Another advantage is its high degree of prefabrication. The work of timber specialists is shifting to the factory and towards digitalisation. They feed the CNC mining machine directly from the original BIM model. So we now plan the project in the office and build it in the factory. We reduce the on site work to a few days. However, despite the potential of wood, there is a problem with its availability.

AK: There is no balance between availability and demand.

DP: Exactly, there is a problem with an increasing demand for timber construction companies. In Austria, 85 per cent of timber construction companies have fewer than nine employees. Only 0.7 per cent have more than 49 employees. The figures for Germany are similar. The demand for wood continues to rise, but timber construction companies cannot adapt their structures as quickly as needed. This is why projects are  often done by large, international companies. However, if you ship timber modules across the continent, you might still build with wood, but certainly not sustainably.
Despite its increasing popularity, timber construction is actually a regional topic. Sustainable building should per se be aligned with its context, considering the local craftsmanship, the regional materials and techniques. Before we as architects draw or design anything, we have to take a close look at the context, and requirements of a project. And this is where I would like to return to my initial thesis: if we respond to needs, we automatically act sustainably, we know which materials to use and how to build.

AK: Mr Philipp, thank you very much for the interview!