AI in building physics: heat, light and algorithms

Building design
Wall with installed laser level for precise measurement, in the context of AI-supported building physics.

How algorithms and modern measurement technology are revolutionizing building physics. Photo by Than Nguyen on Unsplash.

AI in building physics: heat, light and algorithms – it sounds like a dream of the future, but it has long been the present on building sites and in planning offices. While some are still struggling with U-values on paper, others have long since been using neural networks for daylight simulations. Anyone who doesn’t get on board now will be mercilessly overrun by the next heat wave. The question is no longer whether AI will revolutionize building physics, but only how radical the change will be.

  • AI technologies are permeating building physics and fundamentally changing simulation, analysis and design.
  • Germany, Austria and Switzerland are at the beginning of a paradigm shift between skepticism, experimentation and pioneering spirit.
  • Algorithms are optimizing heat and light calculations, accelerating planning processes and enabling more sustainable buildings.
  • Digital tools challenge the traditional understanding of engineering and demand new skills.
  • The use of AI offers opportunities for energy efficiency, comfort and climate protection – but also risks due to black box models and data dependency.
  • AI-based tools are shifting roles in planning teams and making building physics an integral part of digital process chains.
  • The debate about control, transparency and responsibility is sparking a new dynamic in the industry.
  • Global pioneers are demonstrating how artificial intelligence is reprogramming building physics – while German-speaking countries are still caught between innovation and bureaucracy.

Thermal insulation, lighting comfort, algorithms: AI as a game changer in building physics

For a long time, building physics was considered a sober craft – characterized by standards, tables and rules of thumb. But the days when building physicists were “U-value prophets” juggling with Excel lists for insulation thicknesses are finally over. Artificial intelligence is shaking up the field at a speed that makes many an expert dizzy. Today, planners train neural networks to identify thermal bridges, have algorithms calculate daylight simulations in seconds and use AI-based optimization processes to spit out component structures for passive houses. Building physics is becoming a field of experimentation for deep learning, big data and smart algorithms. The traditional interface between architecture and technology is shifting – and with it the self-image of an entire profession.

Germany, Austria and Switzerland are regarded as ambitious, but also stolid. While AI-based simulation platforms have long been standard in international research clusters, German-speaking countries remain cautious. Initial pilot projects in Vienna, Zurich and Munich show what is possible – such as automated design optimization based on building databases or the dynamic control of shading elements using learning algorithms. But the big breakthrough has yet to come. There are many reasons for this: technical uncertainties, regulatory gray areas and a deep-rooted skepticism towards black box systems. Who wants to take responsibility for an AI-generated energy concept if the proof has to be provided in court or in fire protection proceedings?

Nevertheless, the innovation curve is pointing steeply upwards. AI-based tools such as generative models for material selection, predictive algorithms for forecasting user behavior or automated mesh optimizations in CFD simulations are conquering the everyday life of planning offices. The speed at which variants are simulated, optimized and visualized today is pushing the boundaries of traditional software – and opening up new possibilities for sustainable, high-performance buildings. The question is no longer whether AI will become part of building physics, but how quickly the industry will adapt.

It is particularly exciting where AI and building physics merge: in the development of adaptive façades, self-learning shading systems or real-time analysis of user comfort during operation. Algorithms use sensor data to predict how temperature, humidity and light will change over the course of the day – and control ventilation, blinds or heating systems accordingly. Humans take a back seat and the machine takes over the fine-tuning of energy processes. For architects and engineers, this means less gut feeling, more data-driven design – and new dependencies on digital tools.

So it’s no wonder that the debate about AI in building physics is heated. Some celebrate the paradigm shift, while others warn of a loss of control and a lack of transparency. But one thing is certain: anyone who continues to work with spreadsheets will quickly be overtaken by algorithms. The future of building physics is digital, adaptive and anything but monotonous.

Digital simulations and AI: from black box to integral tool

Traditional building physics simulation always had one decisive disadvantage: it was slow, complex and usually only operated by specialists. With the triumph of AI, this is changing rapidly. Suddenly, hundreds of variants for daylight, thermal insulation or acoustics can be calculated in minutes instead of days. Machine learning models analyze huge amounts of building data, recognize patterns that escape the human eye and suggest solutions that surprise even experienced experts. What used to be considered a black box is now becoming an integral part of digital process chains – provided you understand what makes the algorithm tick.

This is one of the biggest challenges: The new tools are powerful, but they require a whole new level of technical understanding. If you want to use AI-supported simulations sensibly, you not only need to know the physical principles, but also how training data is processed, which parameters influence the models and how to interpret results critically. Building physics is thus becoming a discipline at the interface between engineering, computer science and data analysis. A traditional degree is no longer enough to cope with the change – further training in data science and algorithmic modeling is becoming mandatory.

At the same time, the roles in planning teams are shifting. Building physicists are becoming data curators, modelers and process managers. Interdisciplinary work is becoming a prerequisite, because without close collaboration with software developers, architects and operators, the potential of AI will remain untapped. New job profiles are therefore emerging in pioneering projects in Switzerland, for example: Data Engineers for building simulation, AI Architects or Digital Building Physicists. The industry is reorganizing itself – and some of the old masters still have to get used to the new reality.

However, the enthusiasm for AI is not undivided. Critics warn against flying blind in a fog of data, errors caused by poor training data or over-optimized models that have little in common with reality. The danger of AI solutions becoming opaque black boxes is real – and poses new liability issues for planners, developers and authorities. Who is responsible if an AI-optimized façade system fails? How can we understand why an algorithm prefers certain variants? The industry must learn to combine digital transparency with physical traceability – otherwise there is a risk of reverting to analog uncertainty.

Nevertheless, the advantages outweigh the disadvantages. AI-supported simulations not only speed up planning, but also create space for creativity and innovation. They liberate building physics from its niche and turn it into a driver of sustainable architecture. Anyone who masters the new tools can orchestrate light, heat and materials with precision – and thus create buildings that are not only efficient but also surprisingly comfortable.

Sustainability Reloaded: AI and the new demand for energy-efficient architecture

Sustainability has long been paid lip service in building physics, often reduced to minimum standards and certificates. AI has given the topic a new dynamic – and a new aspiration. Today, building concepts can be examined in real time for their ecological footprint, variants can be compared and optimization potentials can be identified that were previously lost in the thicket of standards. AI models not only calculate energy requirements, but also predict how user behavior, climate change or material aging will affect the performance of a building. Suddenly, sustainability is becoming concrete, measurable – and uncompromisingly verifiable.

In German-speaking countries in particular, the potential of AI for sustainable building physics is still underestimated. The discussion often revolves around costs, liability and data protection – yet AI-based tools could accelerate the transition to climate-neutral buildings like no other technology. Adaptive shading systems, smart controls for heating and cooling or predictive maintenance concepts do not arise by chance, but are based on data-driven models. The best examples can currently be found in research buildings, innovation districts or pioneers such as ETH Zurich or TU Vienna. However, the path to widespread use is rocky – and involves education, standards and a cultural change in planning.

The sustainability challenges are enormous. Energy efficiency alone is no longer enough – we need life cycle analyses, resource optimization and the integration of renewable energies into complex building systems. This is where AI comes into its own: It recognizes patterns in consumption data, identifies weak points in operation and suggests targeted measures to reduce CO₂ emissions. Machine learning algorithms can even predict how building concepts will perform under changing climate conditions – an invaluable advantage in times of increasing weather extremes.

But here too, technology alone is not enough. The integration of AI into sustainable building physics requires new skills, open data platforms and close collaboration across disciplines. Architects, building physicists and operators must learn to deal with uncertainties, validate models and critically scrutinize results. The future of sustainable architecture is not being created in an ivory tower, but in the interaction between humans, algorithms and the built environment.

The vision is clear: AI makes sustainability an integral part of architectural quality – and gives building physics the role it deserves. Not as a brake pad, but as a driver of innovation for the buildings of tomorrow.

Global influences, local blockades: Between pioneering spirit and paragraphism

An international perspective shows: While AI has long since become the standard in building physics in the USA, Scandinavia and the Far East, German-speaking countries remain in experimental mode. Global tech companies are investing billions in smart building technologies, start-ups are developing self-learning lighting systems and automated energy concepts, and entire districts in Singapore are being optimized using AI. The architecture industry is facing a turning point – and Germany, Austria and Switzerland are in danger of missing the boat. The reason? Bureaucratic hurdles, fragmented responsibilities and a deep skepticism towards the loss of control through algorithms.

The dispute over responsibilities is symptomatic. Who is liable if an AI-optimized building does not perform? How can it be proven that a machine learning model is physically correct? The industry is looking for answers – and has so far only found them in pilot projects and research laboratories. Politicians are struggling with standards and approval procedures, planners with the complexity of new tools and building owners with the question of who they can trust at all. As a result, many innovations remain stuck at the prototype stage, while global competitors have long since scaled up.

But there are rays of hope. In Zurich, for example, platforms are being created that provide AI models for building physics as open source, making access easier for everyone involved. In Vienna, planning processes are being digitalized in order to integrate AI optimizations directly into the design phase. And in Germany, the number of start-ups with fresh ideas for lighting simulation, energy concepts and smart buildings is growing. The industry is waking up – even if there is still a long way to go from individual projects to widespread application.

The debate about AI in building physics is more than just a technical dispute. It is about the fundamental question of how much decision-making power can be delegated to algorithms – and how planners, operators and users can assert themselves in an increasingly data-driven construction world. Anyone who views AI purely as a tool is underestimating its disruptive potential. Building physics is being reprogrammed – and with it the self-image of an entire industry.

In the end, the realization is that those who ignore AI will not only miss out on the global discourse, but also risk degrading building physics to a mere service – controlled by software, controlled by data and decoupled from architectural quality. The challenge is to actively shape the new tools instead of passively enduring them. This is the only way for building physics to remain what it should always be: a driver of innovation, sustainability and architectural excellence.

Conclusion: Algorithm beats rule of thumb – and building physics reinvents itself

The integration of artificial intelligence into building physics is not a fad, but the beginning of a new era. Heat, light and sound are no longer calculated by hand, but optimized, simulated and controlled by algorithms. For planners, this means getting out of the comfort zone and into the digital arena. Those who seize the opportunities can create more sustainable, comfortable and efficient buildings than ever before. Anyone who hesitates will be overrun by the next wave of innovation. Building physics is becoming a playing field for AI – and those who don’t play along will be left on the sidelines. Welcome to the age of algorithmic building physics – where the thumb value has finally had its day.

POTREBBE INTERESSARTI ANCHE

Neuland – Short lectures by the Modern and Contemporary Art specialist group

Building design
The new digital format is intended to present and discuss issues and projects in six-minute short presentations. Photo: Association of Conservators

The new digital format is intended to present and discuss issues and projects in six-minute short presentations. Photo: Association of Conservators

The speaker team of the VDR Modern and Contemporary Art Section invites you to Neuland on March 24, 2021 from 19:30 – 21:00. The new digital format is intended to present and discuss current issues and projects with several short lectures of around six minutes Neuland is a digital lecture series that will take place for the first time via Zoom on March 24 at 7:30 pm. […]

The speaker team of the VDR Modern and Contemporary Art Section invites you to Neuland on March 24, 2021 from 19:30 – 21:00. The new digital format is intended to present and discuss current issues and projects in several short lectures lasting around six minutes

Neuland is a digital lecture series that will take place via Zoom for the first time on March 24 at 7.30 pm. With changing topics, the aim is to provide a space for networking and the opportunity to exchange ideas, regardless of location. The special thing about Neuland is that the contributions are not directly about the restoration of a work or best practice instructions. Instead, the open topics are intended to encourage participants to look at projects, restoration work or ideas in the field of modern and contemporary art from a specific perspective.

The following course lectures will kick off the first event:

Julia Hartmann: Victor Vasarely – and the search for the right material

Thomas Prestel: Light and object life in contemporary art – should we rethink lighting strategies?

Mona Konietzny: Adhesive mesh as a technique for bonding fabric – and more?

Sophie Bunz: Methyl cellulose foam – thoughts and experiences on recipes and instructions in conservation

To participate, please send an e-mail to: “moderne-kunst@restauratoren.de”. You will then receive the link for the Zoom conference. Please note that the event is already fully booked due to high demand. The VDR specialist group will be offering a follow-up event soon.

Petra Kahlfeldt: Criticism of Berlin’s new building director

Building design
The BDA Architecture app is here!

The BDA Architecture app is here! (Photo: Paul Siewert via Unsplash)

Since architect Petra Kahlfeldt was appointed Berlin’s new Senate Building Director at the end of December 2021, criticism has been raining down from the German architecture scene. There is talk of a “victory for Berlin’s traditionalists” and that Petra Kahlfeldt’s previous commitment is in “stark contrast” to Berlin’s current challenges. In the context of the debate, the opinions […]

Since architect Petra Kahlfeldt was appointed Berlin’s new Senate Building Director at the end of December 2021, criticism has been raining down from the German architecture scene. There is talk of a “victory for Berlin’s traditionalists” and that Petra Kahlfeldt’s previous commitment is in “stark contrast” to the current challenges facing Berlin. The debate brings together the opinions of two highly renowned German architects. An overview of the current situation – including Petra Kahlfeldt’s first public reactions – by Theresa Ramisch, editor-in-chief of G+L – Zeitschrift für Landschaftsarchitktur und Stadtplanung.

It has been clear since December 2021 that architect Petra Kahlfeldt will succeed Regula Lüscher and Hans Stimmann. Petra Kahlfeldt will become Senate Building Director in the Berlin Senate Department for Urban Development, Building and Housing under Senator Andreas Geisel. She thus helps to determine the cityscape and overall planning of Berlin. Regula Lüscher, who is Swiss, held the office of Senate Building Director for 14 years. She retired in July 2021. Berlin’s former building senator Sebastian Scheel kept the position vacant until after the parliamentary elections. Petra Kahlfeldt’s appointment is currently drawing a protest from the German architecture scene.

Petra Kahlfeldt (*1960 in Kaiserslautern) studied architecture in Berlin and Florence from 1979 to 1985. After studying architecture, she worked at the Berlin architecture firm Henning Pohle and also worked independently in an office partnership with her husband Paul Kahlfeldt from 1987 until her appointment as Senate Building Director in 2021. She was also a research assistant at the Chair of Design and Building Construction at TU Berlin from 1990 to 1995. From 2001 to 2003, she chaired the BDA Berlin. Between 2004 and 2009, she taught as Sutor Professor for Monument Conservation and Design at the Hochschule für Bildende Künste and at HafenCity University in Hamburg. Since 2004, she has been a professor in the teaching and research field of “Historical Building Constructions, Monument Conservation and Design” at the Hamburg University of Fine Arts, HafenCity Hamburg, the University of Bologna and the Berlin University of Applied Sciences. She is also a member of various advisory boards. More about Petra Kahlfeldt here.

Opponents describe the decision as an affront

In the run-up to the appointment, numerous renowned architects, academics and initiatives had already called for a transparent and open process for filling the position. 450 architects, initiatives and associations had signed an open letter “For an open and transparent selection of the new Senate Building Director”. On Monday, December 20, 2021, the SPD officially announced that Petra Kahlfeldt would take over the position of the new Senate Building Director. Since then, there have been numerous comments in various media about Petra Kahlfeldt’s appointment. One of the loudest voices is probably the initiative around HG Merz, Philipp Oswalt and Matthias Sauerbruch. On archplus.net, they published a text with the subtitle “Declaration of war on a social and ecological urban policy” in the wake of Petra Kahlfeldt’s appointment. In it, they describe the appointment without a selection process and public discussion as an “affront to the signatories” of the above-mentioned open letter.

Criticism of Petra Kahlfeldt: conservative and pro-privatization

According to the publication, Petra Kahlfeldt’s “previous job profile is in stark contrast to the current challenges facing Berlin”. Together with her husband, she has so far been “responsible for the realization of villas and luxury residential complexes in the upper price segment”. According to the report, Petra Kahlfeldt does not stand for “a city oriented towards the common good”, “sustainable, climate-friendly urban development” or “affordable housing construction oriented towards the common good”. It threatens to “relapse into the ideological trench warfare of an era in which key issues for the future were neglected for a long time”. She is “close to conservative circles that have campaigned for the reconstruction of the city according to historical patterns”. She has also “repeatedly advocated the privatization of public spaces”. Kahlfeldt is co-author of a Berlin position paper “in which a far-reaching privatization of public land in the center of Berlin is called for”. Petra Kahlfeldt had “also repeatedly reaffirmed this position in later speeches”. Therefore, “considerable conflicts in Berlin’s urban society” and building policy blockades are to be expected.

Withdrawal of the appeal demanded

The text was signed by the following planners:

Those involved are calling for the appointment of Petra Kahlfeldt as Senate Building Director to be withdrawn and for an open and transparent selection process to be carried out “that is appropriate to this important office and worthy of a capital city”. You can read the exact wording here.

Matthias Sauerbruch on Petra Kahlfeldt: “no experience with more complex participatory processes”

The initiative is not alone in its criticism. Architecture critic Nikolaus Bernau described the appointment of Petra Kahlfeldt in the Berliner Zeitung as a “victory for Berlin traditionalists”. He came to the conclusion that the “well-situated bourgeois architectural aesthetic a la Kahlfeldt & Kahlfeldt” could not cope with the current challenges facing Berlin.
In an interview with Die Welt, the renowned architect Matthias Sauerbruch said: “Petra Kahlfeldt is a colleague who has simply run an architecture firm, who has taught to a certain extent at various universities and has sat on a number of juries. She is a very friendly and communicative person, but has no experience with more complex participatory processes or administration at city or state level.”

Petra Kahlfeldt represents positions that run completely counter to the coalition agreement

The Association of German Architects Berlin in turn published a statement entitled “New appointment of the Senate Building Directorate lacking transparency and vision” in which it defines the new appointment “according to apparently party-political criteria” as a missed opportunity to fill the “office that is so important for the development of the city with the support of the professional public.”

In a guest article on freitag.de, Kristin Feireiss and Matthias Grünzig, who also signed the publication on archplus.net, also spoke out in more detail. Here they once again point out the missing examples of affordable housing and the planning of new urban quarters in Kahlfeldt’s portfolio. Furthermore, Petra Kahlfeldt has no experience in managing administrations. At the same time, she represents positions “that run completely counter to the coalition agreement”. As a member of the Stadtkern planning group founded in 2011, she has been advocating the privatization of public properties and areas for years.

Arno Lederer positions himself against Matthias Sauerbruch

In a guest article on welt.de, Arno Lederer, on the other hand, deliberately takes a stand against the criticism of Petra Kahlfeldt and also against some of his fellow architects. “This defamation harms all architects” is the title of his article. In it, he describes Petra Kahlfeldt as a “renowned and widely respected architect” and asks directly whether Matthias Sauerbruch’s statements about Petra Kahlfeldt are defamatory. The interview is peppered with half-truths and insinuations. According to Lederer, Matthias Sauerbruch’s statements left behind a “deliberately manipulative devaluation of the Senate Building Director”. He had even considered whether the interview with the “intelligent and thoroughly charming colleague Sauerbruch” was a fake. At the same time, he is harsh on the eight “esteemed” colleagues who are calling for the appointment to be withdrawn. They do not “even have the linguistic skill to formulate the accusations in a question to the future Senate Building Director”.

Lederer: BDA should call for constructive dialog

In his guest article, he also addresses the BDA and its members directly. He asks whether this is really the way they want to deal with each other. It is a public office that is at stake here, not an individual building. Mutual defamation in public created the image of an “already quarrelling bunch that – for this very reason – should not be taken into consideration”, said Lederer. The demands for a transparent selection process were justified. The open letter had shown that German architects could speak with one voice. What followed was shameful. The BDA would now be well advised to firstly stand up against the public defamation and secondly to call for constructive dialog on the other side.

Berlin architecture critics Zohlen and Haubrich back Petra Kahlfeldt

But Petra Kahlfeldt also received support from other quarters. Alongside Arno Lederer, Berlin architecture critic Gerwin Zohlen also accused the authors of the archplus publication of defaming Petra Kahlfeldt and her architectural oeuvre. In his article, journalist and architecture critic Rainer Haubrich also described the new Senate Building Director as “a good choice”. In turn, Berliner Zeitung publisher Holger Friedrich defined the new SenateBuildingDirector in a debate article entitled “Wenn Frauen bauen: Zum Start von Senatsbaudirektorin Petra Kahlfeldt“, defined the appointment of Petra Kahlfeldt as an “opportunity”. The uproar surrounding her appointment would confirm an opportunity for a new start. The Berlin group of Stadtbild e.V. also publicly welcomed the appointment. Its founder Peter Dobrink wrote in the Berliner Zeitung that Petra Kahlfeldt stands for creative openness, harmonious proportions and local traditions. And that is exactly what Berlin needs now.

In a nutshell: the criticism of Petra Kahlfeldt

To summarize, a total of eight German architects and planners – indirectly supported by the BDA Berlin – have publicly denied that the new Senate Building Director is competent for the position. They accuse her of having outdated views. According to the critics, these are contrary to the modern, sustainable urban design that is now needed in Berlin. Petra Kahlfeldt is accused of approving the privatization of public real estate and spaces in Berlin’s city centre. In the past, she and her architectural firm have primarily realized luxury buildings and villas and have therefore not acted in the interests of the common good. The critics also question whether Petra Kahlfeldt can and wants to promote participatory processes in the sense of a participation-oriented urban society.

Petra Kahlfeldt responds to criticism

What is Petra Kahlfeldt’s opinion on all this? She has since responded to the criticism in various interviews. G+L has also been able to talk to her. In it, she points out that the post of Senate Building Director is not only a professional position, but also a political one. This is often forgotten. She is also surprised that she has been criticized before she has even been able to make a substantive decision. And in an interview with Die Welt, she also discusses her urban development vision. “My guiding principle is the compact European city,” is the headline of the article. And Die Zeit quotes Kahlfeldt as saying: “There will be more high-rise buildings”. However, both articles are subject to a charge.

However, an interview with Petra Kahlfeldt is freely available on radioeins.de. Here she explains her job in general and that she sees herself as a bridge builder in her new position. When asked whether she has experience with a larger scale or the creation of affordable housing, Petra Kahlfeldt replies that her traditional professional focus is actually on conversion areas. These were sometimes larger urban quarters or individual buildings. Her traditional area, however, is the design and construction of existing buildings. Petra Kahlfeldt answers the question of whether Berlin Mitte needs more privatization instead of social housing in the negative. There is a good reason why Berlin has decided not to sell state-owned planning areas. When asked about her proximity to the Stadtkern planning group, Petra Kahlfeldt replies that the group is defined by its interdisciplinarity. This is also where instruments are discussed with urban planners that can be established contrary to speculation. You can listen to the whole interview here.

In an interview with G+L editor-in-chief Theresa Ramisch , the new Berlin Senate Building Director Petra Kahlfeldt comments on the accusations made against her.