27.01.2026

Lumen as a design tool: light meets architectural visions

Building design

The photo by Yuhei Abe Studio shows the powerful shadows of an escalator that create exciting lighting effects in an urban setting.

Lumen as a design tool – sounds like just another buzzword in the architect’s toolbox, but in reality it is nothing less than a revolution in our spatial thinking. Light has long since ceased to be an atmospheric accessory and has become a central player that shapes buildings, cities and even entire societies. Anyone who still regards light as a static factor has missed the signs of the times – and is missing the opportunity to lead architecture into the future.

How light works as an active design tool in architecture – technically, aesthetically and socially.
Innovations in daylight and artificial lighting design between digitalization, simulation and adaptive control.
The role of artificial intelligence and digital twins in lighting design.
Specific challenges and solutions for sustainable lighting concepts in the DACH region.
The specialist knowledge and skills that architects and planners need today.
Debates about light pollution, user comfort, health and energy efficiency.
How lighting design influences global discourse – from smart cities to climate protection.
Visionary approaches, criticism of technocratic light fetishism and an outlook on the future of light in architecture.

Light as a guiding material – from atmosphere to strategy

Anyone walking through cities in Germany, Austria or Switzerland today usually encounters light in its most well-behaved form: functional, standardized, sometimes decorative – rarely visionary. Yet light is not a static material, but a formative force that not only illuminates spaces, but transforms them. Lumen has long since become a design unit, a strategic tool that creates atmosphere, orientation and identity at the same time. While classic lighting design was satisfied with lux values and the choice of illuminant, contemporary architecture thinks of light as a narrative and performative component. In projects such as the Kunsthaus Graz, the Elbphilharmonie concert hall or Vienna Central Station, light becomes a staging, a choreography, an invisible hand that brings buildings to life. But the path to this is a rocky one: architects today are faced with the task of not just setting light, but orchestrating it – between user comfort, sustainability and technical innovation. They are increasingly taking on the role of conductors, using sensors, AI and adaptive controls to play a complex game between day and night, inside and outside, efficiency and emotion. The paradigm shift is marked by the fact that light is no longer seen merely as an energy consumer, but as a central control medium for climate, well-being and spatial perception. Lumen is no longer an accessory – it is substance, strategy and challenge at the same time.

The dynamics of innovation in the field of lighting design are both impressive and demanding. Digitalized planning processes, parametric simulations and real-time feedback open up new horizons, but also place high demands on specialist knowledge and willingness to cooperate. While traditional lighting design was often carried out in late service phases, digital tools such as DIALux, Rhino or Grasshopper require much earlier integration into the design process. Anyone who wants to design with light today has to simulate beam paths, optimize glare levels, maximize the use of daylight and take the EU’s energy targets into account at the same time. This sounds like an overwhelming challenge, but above all it is an invitation to redefine one’s own role. The boundaries between architect, lighting designer, engineer and data scientist are becoming blurred – opening up the opportunity to establish light as the leading material of the future.

In the DACH region, lighting design is characterized by an ambivalent attitude: on the one hand, there is an awareness of light as an architectural leitmotif – think of Swiss museums or Austrian cultural buildings. On the other hand, in many places the fear of light pollution, violation of standards or waste of energy still dominates. This tension creates friction, but also pressure to innovate. While adaptive façade solutions and light-directing materials are being tested in Zurich and Vienna, many municipalities are still limiting themselves to replacing light sources with LEDs. The real challenge is to understand light as a dynamic system – not as a static variable, but as part of a networked, digital and sustainable urban fabric.

Lighting design has long been part of the global architectural discourse – not least because it directly affects key issues such as climate protection, health and social justice. The question of how much light, which light and whose light dominates in our cities is not a technical issue, but a social one. The responsibility of planners lies in designing light not just for users, but with them. Participation, transparency and digital interfaces are not luxury problems, but basic prerequisites for a sustainable lighting culture. Those who ignore this not only risk bad architecture, but also miss the opportunity to use light to create spaces for everyone.

All in all, it is clear that lumen as a design tool is not a trend, but one of the central challenges and opportunities of tomorrow’s architecture. Anyone who still regards light today as purely an energy issue has already lost the game. It’s about more – much more. It’s about identity, atmosphere, sustainability and ultimately the question of how we as a society deal with the oldest of all design tools.

Digital transformation: how AI and simulations are rethinking light

Digitalization is radically transforming the field of lighting design. What used to start with hand drawings and thumbnails is now controlled by algorithms, simulations and digital twins. The development of lighting concepts is no longer limited to empirical values and standard tables – it is data-based, iterative and highly dynamic. Programs such as DIALux, Relux and Rhino not only enable precise calculations, but also real-time feedback on daylight sequences, glare risks and energy consumption. Particularly exciting is the use of artificial intelligence, which is setting new standards in the optimization of lighting management, control and maintenance. AI can anticipate lighting sequences, analyze user behavior and control adaptive systems that adjust to changing requirements in real time.

Digital twins are increasingly becoming the centerpiece of lighting design – at least in the pioneering cities. A digital twin of a building or district makes it possible to simulate lighting effects, reflections, shading and even the influence of weather or pollution. In Zurich, for example, entire districts are already being equipped with real-time light simulations to test the impact of new buildings on public spaces. Vienna is experimenting with adaptive lighting systems that use sensors and AI to automatically adjust to the volume of users and the time of day. This clearly shows that the days of fixed lighting times and on/off switches are finally over.

In Germany, however, skepticism still often dominates. The integration of digital lighting planning tools is perceived by many as too complex, too expensive or too technical. Yet it is precisely these tools that offer enormous potential for sustainability, user comfort and cost-effectiveness. The challenge is to master the interface between architecture, technology and user experience – without falling into technical fetishism. Anyone who sees light merely as a playground for nerdy software experiments forgets that, in the end, the focus must still be on people.

The influence of digitalization on lighting design can hardly be overestimated globally. In Singapore, for example, entire districts are being equipped with AI-controlled lighting systems to minimize energy consumption while maximizing the quality of stay. In Copenhagen and New York, public spaces are being equipped with adaptive lighting scenarios that react to events, weather and user movements. The race for the smartest, most sustainable and most user-friendly lighting solution has long since begun – and German-speaking countries must be careful not to be left behind.

The central question remains: How much digitalization can lighting design tolerate without losing its poetic, social and cultural dimension? Light is more than an algorithm – but without digital tools, it often falls short of its potential. The art lies in understanding technology as an enabler, not as an end in itself. Anyone who understands this can create something truly new with light.

Sustainability and responsibility: light between resources and quality of life

The sustainable design of light is the great unsolved puzzle of the industry. On the one hand, light is indispensable – for safety, orientation, well-being and identity. On the other hand, light is one of the largest energy consumers in building operation and a central source of light pollution. The balancing act between comfort and climate protection is challenging, but unavoidable. In Germany, Austria and Switzerland, the requirements are strict: Energy Saving Ordinance, EU taxonomy, national climate targets – all require lighting systems to be efficient, durable and recyclable. Switching to LED was only the first step. Today, the focus is on adaptive systems, daylight-dependent controls, presence-controlled luminaires and intelligent maintenance.

But sustainability is more than just energy efficiency. It is also about the choice of materials, life cycle, maintenance requirements and social sustainability. An office flooded with light may be more demanding in terms of energy, but it increases productivity and health – which in turn creates added social value. The debate about light pollution brings another level into play: cities such as Zurich, Basel and Munich are experimenting with dynamic lighting concepts that dim down at night or specifically illuminate certain zones. The aim is to protect flora, fauna and people’s natural biorhythms without sacrificing quality of life.

The technical implementation of sustainable lighting concepts requires a deep understanding of control technology, sensor technology and user behavior. Architects and planners must learn not only to design lighting systems, but also to operate and maintain them. This requires new skills and close cooperation with engineers, manufacturers and users. The traditional silos of the industry are beginning to falter – and that is a good thing.

From a global perspective, the pressure on sustainable lighting design is intensifying. Cities such as Paris, Milan and Toronto are setting benchmarks for adaptive lighting concepts that address energy consumption, user comfort and biodiversity in equal measure. The lesson to be learned: If you are too late, the electricity meter will punish you – and so will public opinion.

The responsibility of planners is enormous. They must understand light as part of an overall ecological, social and economic system. Sustainability is not an add-on, but an integral part of good lighting design. Those who ignore this will at best produce interchangeable standard solutions – and at worst light smog, energy guzzlers and social exclusion. The time of the naive sea of light is over.

Technical expertise and debates: Between technology, art and ethics

Lighting design today is a field for generalists and specialists alike. Anyone who wants to design with lumen needs technical know-how, creative sensitivity and ethical awareness. The requirements are increasing: radiation physics, color rendering, glare limitation, control technology, knowledge of standards – all of this is part of the repertoire. But empathy, communication and the ability to mediate between different disciplines are just as important. Training often lags behind developments. While specialized Master’s courses and further training are booming in Switzerland and Austria, in Germany the subject of lighting design is still too often a marginal topic in architectural training. This takes its toll in everyday professional life, where incorrect planning, poor coordination or a lack of knowledge can quickly lead to expensive rework.

The debates surrounding lighting design are varied and sometimes heated. While some insist on maximum efficiency and standardization, others plead for more courage for staging and individuality. The fear of light pollution, glare and energy wastage contrasts with the desire for atmosphere, identity and quality of stay. Particularly controversial: the question of how much design freedom digitalization actually allows. Will the architect become a vicarious agent of algorithms, or will technology open up new freedoms for creative solutions? Opinions differ, and that’s a good thing. After all, innovation only comes about through debate.

Another contentious issue: who is actually responsible for good lighting design? The architect? The lighting designer? The user? Or ultimately the AI that regulates everything automatically? The answer is as simple as it is uncomfortable: everyone. Good lighting design can only be created through dialog – between planners, technicians, users and operators. Those who shirk this responsibility produce mediocrity at best.

The global debate on lighting design is characterized by visionary projects, but also by growing criticism of technocratic lighting fetishism. In Asia and North America, lighting design is increasingly being used as a marketing tool – sometimes at the expense of sustainability and user comfort. In Europe, on the other hand, there is a growing awareness of the limits and side effects of light as a design tool. The challenge is to balance vision and responsibility, technology and poetry.

In the end, the question remains: how much light does architecture need – and how much darkness can it tolerate? The answer is individual, context-dependent and constantly changing. One thing is certain: if you don’t interfere, you will be shaped – by algorithms, standards and electricity bills.

Outlook and conclusion: Lumen as the key to the architecture of tomorrow

Light as a design tool is not a trend, but the key to the future of architecture. In the interplay of technology, sustainability and social responsibility, light is becoming a touchstone for innovation and quality. Digitalization opens up unimagined possibilities, but also demands new skills and a critical awareness. In Germany, Austria and Switzerland, the industry is on the move – between experimentation, caution and excellence. Those who design light courageously, competently and responsibly can create spaces that inspire, protect and connect. Those who shirk technology or responsibility will remain stuck in mediocrity.

The future belongs to those who see light as an active medium – not as an accessory, but as a strategy. It’s not about more or less light, but about the right light, at the right time, in the right place. The architecture of tomorrow will not be characterized by walls, but by lumens. Those who understand this are not only designing spaces, but the society of tomorrow. Welcome to the age of intelligent light.

05.11.2024

New master houses for Dessau

Building design

The famous Meisterhaus estate has been repaired, according to Dessau. Repaired, not reconstructed. This language is important to politicians, conservationists and architects, because for decades there was a dispute about how to deal with the famous Meisterhaus estate near the even more famous Bauhaus buildings in Dessau. There were loud calls to rebuild the two houses that were hit by a bomb in 1945 – […]

The famous Meisterhaus estate has been repaired, they say in Dessau. Repaired, not reconstructed. This language is important to politicians, conservationists and architects, because for decades there was a dispute about how to deal with the famous Meisterhaus estate near the even more famous Bauhaus buildings in Dessau. There were loud voices rejecting the rebuilding of the two houses that were hit by a bomb in 1945 – the single Gropius house and the semi-detached Moholy-Nagy house.

However, after the existing Masters’ Houses were restored in 1992, the flaws became all the more apparent. After several projects by the Bauhaus Dessau Foundation on the issue of “updating modernism” and several architectural competitions, it was not only the city – as the owner of the estate at the time
owner of the estate at the time – that the entire artists’ colony could only be visualized in a way that was compatible with the preservation order if the building lines and cubatures of the destroyed buildings were also restored.

On May 16, Federal President Joachim Gauck opened the “repaired estate”, which now once again consists of the house of director Walter Gropius and the three semi-detached houses Moholy-Nagy/Feininger, Muche/Schlemmer and Klee/Kandinsky.

The two new houses correspond exactly to the old ones in terms of their external dimensions, the arrangement of the structures and the position of the windows. However, with “built blurs”, as the Berlin architects Bruno Fioretti Marquez describe their way of repairing the Meisterhaus estate as a total work of art. Seen from the outside, this means that any view through the gray window surfaces is denied. The houses appear almost ghostly and a little unreal. Inside, the principle of “built blurriness” continues elegantly and effortlessly. The historical position of ceilings, walls and staircases was taken as a model, but parts of the ceilings and walls were omitted. In this way, completely new views, rooms and balconies were created in the dimensions of the original layout, which seem far removed from the intimacy of the neighboring, originally preserved residential buildings and yet are closely related to them. Uta Baier
You can read a detailed review of the reconstructed Dessau master houses in issue 07.2014.

09.12.2024

“Warnow offers Rostock a unique opportunity”

Building design

A conversation about the BUGA 2025 in Rostock with Anja Epper, Head of Department at the Rostock Office for Urban Development, Planning and Economy.

The city of Rostock plans to host the BUGA 2025 in a few years’ time, and a completely new district at the Osthafen is set to become one of its core projects: the Warnowquartier – funded with a total of 74.2 million euros. Last summer, we spoke to Anja Epper, Head of Department at the Rostock Office for Urban Development, Planning and Economy, about Rostock’s water projects of the future for the June 2020 issue of Garten + Landschaft.

Anja Epper, we start with a current project of the city of Rostock. The Hanseatic city has been working for almost ten years to update the structural concept for Warnemünde, probably the city’s best-known district. However, there are always problems with implementation. Why?

In 2011, the Rostock city council adopted the Warnemünde structural concept. Regular evaluation was already anchored in the resolution. The process of updating the concept began in 2016/17. A number of questions relating to the various fields of action in the structural concept could not be answered in the update, either because political decisions were not available at the time or because decisions could not be made.

This concerned, among other things, the further development of the shipyard areas in the south-east of the district, the handling of the parking space concept, the further development of a possible caravan site and the development of the housing market. Another key topic was the future development of the Mittelmole. Here, it was not possible to reach a consensus on a few key points in civil society and politics, but also with the owners of the land and the specialist administration.

As a result, the new mayor of Rostock, Claus Ruhe Madsen, halted plans for the future use and development of Warnemünde’s Mittelmole for the time being last September. Why is the development of the area so difficult?

Further planning for the central pier in Warnemünde was put on hold last year. With the mayor’s decision, we are starting the work process again, including participation in the update. As in many places, there is a classic conflict at the Mittelmole: the residents want no or very small-scale or minimal development with a more historicist design. At the same time, there is a strong desire for communal open spaces and meeting places. Investors want to build the necessary apartments and infrastructure, but these must also be considered from an economic point of view. In addition, contemporary architecture is generally required for new construction projects.

There was supposed to be a public exhibition at the start of the public participation process last April. Then came the coronavirus pandemic. What is the plan now?

The coronavirus pandemic has had a major impact on public participation in planning processes – possibly even in the long term. We are therefore currently considering which participation formats we can implement online. These include an exhibition. But with all digital solutions, there is always a lack of direct exchange. This is particularly difficult with informal participation. We are also looking for appropriate solutions for other formats such as public meetings, which can be held in small groups and with the necessary minimum distance.

Water as an economic basis

As a Hanseatic city, you in the Rostock Office for Urban Development, Urban Planning and Economics are particularly confronted with how to deal with water in the city. What significance does the element of water have for the city of Rostock?

The relationship to water has always been of outstanding importance in the history of the city. The city’s urban and economic development is still based on its location on the Baltic Sea/Warnow – and will continue to be so in the foreseeable future. In particular, ports, shipbuilding, the navy, tourism and fishing are to be mentioned here. It is precisely the facets and changes in these areas that are constantly driving urban development. In addition to the increasing demand for living space and all the associated facilities for the numerous employees, these are the location requirements in detail, such as more and different areas as well as their access and connection, but also relocations or the abandonment of areas, which opens up new planning possibilities.

In principle, planning is about securing water and all necessary areas as an economic basis and at the same time improving access and the experience of water for the public. Of course, the many ecological and nature conservation concerns must also be taken into account in this context.

Taking sea level rise into account

What particular challenges do you face in Rostock due to its proximity to the sea?

One particular challenge is protection against storm surges, i.e. flood protection. The technical responsibility for flood protection lies with the State Office for Agriculture and the Environment, Central Mecklenburg (StALU MM). The StALU MM is responsible for the protection of the outer coast as well as the protection along the Warnow. There is a constant coordination process between the StALU MM and the city (primarily the Office for Environmental Protection, but also the Office for Urban Development, Urban Planning and Economics). This relates to fundamental issues such as the course of the flood protection line and keeping endangered areas free of construction use, but also to the specific individual construction measures.

From an urban planning perspective, the focus is on ensuring the necessary protection for planned new construction areas (including the height of roads and floors), but also on the form of construction and design of protective facilities (especially in sensitive areas such as the Alter Strom in Warnemünde and the city harbor). Another important topic is the consideration of the rise in sea level caused by climate change.

Rostock: a green city by the sea

You have been working on the “Rostock Future Plan” since 2018. What is this about?

The “Rostock Future Plan” is the working title for the future land use plan of the Hanseatic and university city of Rostock. The land use plan adopted by the city council in 2006 and published in 2009 has so far proved its worth as a preparatory, generalized plan for controlling the city’s spatial development. However, based on the development dynamics expected in many areas in the future, it is becoming apparent that the land use plan currently in force does not adequately reflect the development required in the future.

The pace at which Rostock must develop in the coming years requires a holistic and coherent reconsideration. The city council therefore decided back in 2017 to draw up a new land use plan. In preparation for this, an extensive city dialog was held in 2018/19 for an intensive public exchange on the contents of the “Rostock Future Plan”.

There are also the “Rostock 2025” guidelines, which define Rostock as a “green city by the sea”, among other things …

Exactly, the guidelines for the urban development of the Hanseatic and University City of Rostock were adopted by the city council in 2012. They represent the long-term strategic framework for action for the city of Rostock on its way to sustainable urban development by 2025. They form the basis for the Integrative Urban Development Concept (ISEK), urban land-use planning and all specialist municipal concepts and plans. This also includes, for example, the “Rostock Future Plan” (land use plan). The future plan is aimed at the overarching mission statement (“Positioning Rostock as a regiopole”) and contributes to achieving the goals set out in the eight guidelines (e.g. the “Green City by the Sea” guideline) and the cross-sectional tasks.

BUGA 2025 projects

Hamburg recently announced its plans for the Grasbrook district. What projects can we look forward to in Rostock in the coming years? What are you planning?

You have already mentioned the Mittelmole in Warnemünde. Linked to this planning is the conversion of further quays in the area of the former shipyard basin for cruise tourism and additional commercial space on land, which is currently being planned. A particularly important project for the urban development of Rostock is the bid to host the BUGA 2025, with many far-reaching individual measures and a direct link to the Warnow.

The State Museum of Archaeology, which is to be built in the city harbor, is part of the plans for BUGA 2025. Another outstanding project with a direct connection to the water is the planned “Ocean Technology Campus” (OTC), with the Fraunhofer Institute for Computer Graphics Research (IGD) at its core and a large-scale underwater test field “Digital Ocean Lab”. The OTC is to be built in the area of Rostock’s cargo and fishing port and on the site of the former abattoir to the south.

The city is also planning to develop a new, mixed-use district on the eastern bank of the Unterwarnow. The Warnowquartier.

Yes, the Warnowquartier is to be developed as a green model city of the future – an experimental quarter that demonstrates exemplary solutions to the pressing problems of our time. Starting with the development of a regenerative energy concept for the district, through to answering the question of how residents can organize their daily lives together in a sustainable way, as well as considering which tasks public open and green spaces should take on in the coming years and how new mobility concepts can be implemented sustainably, innovative ideas and proven measures for district development are to be incorporated into the concept.

The aim is to create a modern district for everyone with a model development and lots of open spaces. A place of diversity and flexible uses with a robust, future-oriented basic structure. Building on the water will also play a special role and form an architectural highlight. For the Hanseatic and university city of Rostock, this project offers a unique opportunity to implement the theme of life on the water in the city for the first time and to present itself with original, forward-looking and exemplary solutions. As part of BUGA 2025, which will take place in Rostock, the main focus for visitors will be on this attraction, which will make a further contribution to the city’s maritime image.

BUGA 2025 is to take place despite the coronavirus pandemic.

Anja Epper studied architecture with a focus on urban planning at RWTH Aachen University. She has been Head of the Building Projects and Urban Design Department at the Rostock Office for Urban Development, Urban Planning and Economics since 1996. Anja Epper is a member of the Mecklenburg-Vorpommern Chamber of Architects and a board member of SRL e.V.

Interested in Federal Garden Shows? Read more about BUGA Heilbronn here.

The interview first appeared in the June 2020 issue of Garten + Landschaft.