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Digitalization for existing buildings

Construction in existing buildings is one of the most important levers on the path to a sustainable future: This is where the greatest potential for resource-saving construction and achieving climate targets lies. After all, the building sector accounts for more than a third of greenhouse gas emissions and around 40 percent of energy consumption in the European Union. Digitalization thus plays a key role in the transformation of existing buildings. digitalBAU 2026 will also focus on the associated challenges, but first and foremost on digitally driven solutions and innovations for dealing with existing buildings in a sustainable manner. One of the four key topics is therefore digitalization and construction in existing buildings.

From an exact survey to planning renovation projects and converting inner-city neighborhoods, digital solutions offer diverse potential for efficiency, sustainability and cost control. In this context, existing buildings are the decisive lever for achieving the climate targets we have set ourselves, as a large proportion of today’s buildings will also still be standing in 2045. Germany is aiming to achieve climate neutrality by then, with a significant reduction in emissions in the building sector already by 2030. That requires a comprehensive energy and structural upgrade. Political measures such as the federal funding program Bundesförderung für effiziente Gebäude (BEG) for efficient buildings set up by the Federal Ministry for Economic Affairs and Climate Protection and the KfW programs provide economic incentives for developers and investors. However, the challenges are complex: The heterogeneity of the existing buildings, decades of renovation backlog, cost pressure and a shortage of skilled workers make digitalization both necessary and essential.

Making existing buildings comprehensible

A successful refurbishment begins with an in-depth understanding of the existing buildings. The as-is status and important life cycle data, the gray energy, and the carbon footprint therefore need to be recorded in as much detail as possible. Modern technologies make it far easier to collect comprehensive and precise inventory data. Key elements for this are:

  1. Inventory digitalization
    It transforms the analog and often fragmented information about existing buildings into logically ordered, digital data models. This is the fundamental basis for any refurbishment project and enables maximum efficiency and transparency regarding the “as-is situation” for all subsequent project steps.

  2. 3D measurement and laser scanning
    Instead of time-consuming manual measurements, digital technologies such as drone surveying or mobile laser scanners can be used to generate millions of measurement points in no time, which are then merged into an as-built model. An accurate image of the existing building – even of complex details – can thus be generated. At the same time, this as-built model forms the basis for digital twins, which can be updated throughout the course of the project.

The digital twin

Digital twins are information models that create a dynamic, virtual image of the real building. In addition to geometric data, they also contain information on building performance, sensor data, components, material compositions or maintenance history. The introduction of Building Information Modeling (BIM) with consistent data management anchored in a 3D model is the key to the digital twin: Different scenarios can thus be simulated, such as the effects of different concepts for a change of use.

© Messe München GmbH

Realistic simulations can also be used to ensure optimized facility management (FM), efficient energy management and, thanks to the wealth of digital information, precise valuation. Large-scale (supra-regional) planning—for example, for entire conurbations or inner-city development areas—can also be digitally simulated and optimized before a single stone has been moved.

Digital building and material passports

Digital building resource passports, such as those offered by the DGNB or the federal state of NRW together with Madaster, increase transparency and form the basis for sustainable decisions and a genuine circular economy. They document not only the condition and energy performance of a building, but above all the materials used, their origin and recyclability, as well as the options for reuse and recycling. The integration of specialized recycling databases is an important step here toward efficiently keeping materials in the material cycle at the end of their life cycle or returning them to the cycle after recycling.

Digital tools for refurbishing existing buildings

  1. Building Information Modeling (BIM)
    BIM is by no means reserved for the new construction sector, but is particularly effective in complex existing buildings. Scan-to-BIM transfers the high-precision data from laser scans into an intelligent BIM model. This eliminates errors caused by manual transfers on old as-built plans, and accelerates precise construction of a digital model. The as-built model is the basis for the subsequent architectural and specialist planning models and enables collaborative work, conflict detection and accurate quantity takeoff at an early stage, which is associated with considerable time and cost savings.

  2. Use of sensor technology
    Intelligent sensors are the “eyes and ears” of a building, so to speak. Smart meters, CO₂ sensors, temperature and humidity sensors, as well as pressure sensors in pipes or motion detectors in the corridors and rooms of a building provide real-time data on the state of repair of the building. This information is the basis for data-based renovation strategies: It identifies and locates weak points such as leaks, thermal bridges or inefficient ventilation. Measures can thus be strategically implemented where they have the greatest impact. Sensor technology also allows decisions to be substantiated and made based on data, making refurbishment projects smarter, more efficient and more sustainable.

The future is now: support from AI

Artificial intelligence (AI) and specialized software tools are revolutionizing refurbishment planning and implementation. AI can analyze huge datasets, identify patterns and suggest optimum refurbishment concepts on this basis, taking account of costs, efficiency and sustainability. Last but not least, these tools already support the task of submitting complex funding applications by automatically compiling relevant data and generating the necessary supporting documents.

The use of AI makes it possible to quickly run through and evaluate countless planning variants, for example, when converting existing buildings: The conversion of former office space into valuable living space can be simulated, the feasibility of the conversion measures checked and their economic viability evaluated. The performance of artificial intelligence is developing rapidly and will fundamentally change the way we continue to automate and optimize complex processes in existing and new buildings.

Energy-efficient refurbishment and smart technology

There is huge potential for combining energy-efficient refurbishment and digital process control, particularly in existing buildings: While energy-efficient refurbishment concerns the physical building envelope, smart technology ensures sustainable efficiency gains in building operation.

Two hands hold a tablet displaying technical monitoring data from buildings.
© Messe München GmbH

Building automation, heating control and user behavior

Modern building automation connects all of the technical systems in a building, from the heating and ventilation to the lighting and solar protection. It is already included in the concept for new buildings, but can also be a problem solver for existing buildings.

For example, smart heating control responds to the room temperature, learns from usage behavior, takes account of weather data, and adjusts the comfort parameters individually. But it is the concerted interaction of building technology, existing building fabric and user requirements that enables predictive energy management, while at the same time ensuring a high level of convenience for users. This approach can therefore also be technically possible and economically viable for the existing buildings.

Identifying qualities in existing buildings: from vacant to smart building

No matter whether it’s about converting an empty village school into a private smart home or an old commercial building into a complex smart building, intelligent planning, networking and consistent digital control systems enable the operating processes to be continuously optimized. Predictive controls ensure that the heating or cooling is only switched when it is really necessary, and, thanks to automated maintenance cycles, problem areas can be located long before the building technology breaks down. Running costs and energy consumption can thus be reduced sustainably and over the entire period of use of a property—decisive factors for the economic viability of refurbishment projects.

Energy monitoring and management in building operation

Real-time data from digital energy monitoring provides the necessary transparency for optimized energy management. In existing buildings in particular, where energy consumption and the associated assessment of energy efficiency have to date often been opaque, digital tools and applications help identify and exploit potential and thus continuously improve performance.

Away from individual measures toward a digital neighborhood solution

Networking at the neighborhood level offers great potential on the path to climate neutrality. Digital solutions therefore enable the development of integrated approaches in existing buildings that are already being used today:

  1. Neighborhood approaches
    Setting up district heating networks, photovoltaic sharing or monitoring energy flows across buildings creates synergies for the neighborhood and makes energy-efficient refurbishment particularly efficient at this level. Digital tools and systems enable coordinated planning and implementation, particularly in a situation involving existing building with a heterogeneous structure.

  2. Platform economy in the neighborhood
    Open systems, interoperable data rooms and digital interfaces are the basis for holistically connected existing buildings. They enable the exchange of neighborhood-related energy data, the shared use of generation and storage infrastructure, and digital services for residents – from load management for the power supply and a smart charging infrastructure for vehicles to neighborhood apps.

  3. The role of public authorities and energy providers
    Municipalities and municipal utilities play a central role a) as initiators and b) as facilitators of digital neighborhood solutions. They create the basic legal and technical framework for using digital neighborhood solutions, promote pilot projects, and actively drive forward overarching digitalization in urban development. Their support is therefore necessary to navigate from individual solutions to a comprehensive, efficient and high-quality neighborhood development – also and above all for existing buildings.

Information on the role of the state and the need for holistic urban development can be found on the website of the Federal Ministry for Housing, Urban Development and Building (BMWSB).

Clear commitment: Plan existing projects digitally. Shape a sustainable future.

The stringent digital transformation of our existing buildings is essential for sustainable construction, the protection of resources, and the effective achievement of the ambitious climate targets by 2045. Digitalization is the key to successful projects in existing buildings, as it makes the challenges of building in existing structures manageable.

Tools such as Scan to BIM, a model-based planning method, or digital neighborhood solutions digitize and optimize previously analog processes. They enable informed decisions and create transparency across the entire life cycle of a building or a complete development. However, the effective use of digital technologies in the future will require binding standards, digital interfaces that are still open, and the targeted education and training of skilled workers, who are becoming increasingly scarce.

Consistently digitize and remove obstacles in a targeted manner

Despite numerous tools, promising planning technologies like BIM, and growing support from AI tools, digitalization is also encountering obstacles when it comes to construction with existing buildings. On the one hand are the investment costs for hardware and software in design and planning or the lack of financing options for project implementation, because lending banks and potential investors need to be convinced time and again. On the other are the lack of digital expertise among those carrying out the work and the acute shortage of skilled workers that need to be considered.

Another problem is the fragmentation of the construction industry. Heterogeneous data structures and a lack of standards among the many small and medium-sized companies in planning and execution make it difficult to exchange digital information and hinder the establishment of digital processes. Added to that are the bureaucratic hurdles due to excessive standards and guidelines in Germany. Targeted funding measures, individual employee training, and a change of mindset in many people’s heads are essential in order to fully exploit the potential of digitalization, also in dealing with existing buildings.

The foundations for successful digitalization construction in existing buildings have already been laid, and innovative research, services and suitable products are available. Visit digitalBAU 2026 in Cologne to find out about the latest developments and solutions. Industry, politics, research, engineering, industry associations and decision-makers will meet in Cologne to drive digital construction forward together. Become part of this community.

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