Information and communication technology is generally becoming increasingly important for buildings and districts: This is because innovative building technology and the electrical, thermal and digital networking of buildings, districts and energy systems can significantly optimise their energy efficiency. This is being researched and tested in many projects.

For new-build schemes, renovation and also for building management, special tools are being developed for simulating buildings and systems and for energy-efficiently balancing individual buildings or districts. Software is also being developed for architecture and specialist planning as well as for project management, quality assurance and operation management. Work is currently being carried out on integrating Building Information Modelling (BIM) concepts and ensuring a continuity of data management from the design and construction of buildings to their operation. The aim is to achieve a digital information flow for all phases of a building or property.

At the district level, geographic information systems are playing an increasingly important role in planning tools, as are specialised systems for energy management and quality assurance as well as models for energy and CO2 balancing.

To enable the optimisation of planning processes, a continuous, digital flow of information is helpful, ranging from the design and execution to the operation and use of buildings and districts. The increasing digitisation of planning processes and the technological trend away from isolated sub-models to multi-scale solutions and, ultimately, the development of international model standards support this demand. The next logical step would be to synchronise Building Information Modelling (BIM) and Computer-Aided Facility Management (CAFM). Here it would also be conceivable to replace existing concepts such as the energy requirement certificate with such data integration and digital building models.

Annual simulations determine the energy demand of buildings and can create load series for heating, cooling and air-conditioning. Specific simulation tools also calculate yields and the coverage provided by systems using renewable energies.  Simulations in building physics and building technology are currently concerned with aspects such as dynamic component simulations, spatial simulations, building simulations and dynamically coupled simulations.

Once buildings have been constructed, they are there to serve the residents and users. And if they feel uncomfortable or unhappy for whatever reason, they will take matters into their own hands and interfere with the operation of the building. As a result, buildings that have been designed in a very energy-efficient manner may end up consuming considerably more energy in actual operation than originally planned. User satisfaction and acceptance of the building concept must therefore be considered in the planning stage alongside any differences in technical understanding or in cultural and language barriers.
User participation, motivation, and qualification are important factors in the success of energy-efficient buildings and districts. It is only by taking these aspects into account that acceptance of the technology being used within certain economic framework conditions can be achieved. The same applies for those involved in planning, building, and operation: iterative and interdisciplinary planning processes help to ensure team-oriented actions within the framework of an integral planning process. This creates a holistic view of buildings and districts, for example on the issue of sustainability throughout the entire life cycle.

The restructuring of the energy system also requires new business models that are in line with the market. When creating these models, researchers need to consider the requirements of operators, suppliers, and consumers. The latter are increasingly taking on the role of “prosumers”, meaning they act simultaneously as energy producers and consumers. The development and trialling of innovative business models is therefore becoming increasingly important.

When implementing effective efficiency measures, the actors involved are dependent on the data and results of reliable analysis and planning instruments. Numerous planning aids have therefore been developed in the past, for example to simplify the development of municipal energy concepts or as software tools for designing and implementing innovative technologies. Currently, the focus is on creating and testing planning tools that integrate Building Information Modelling (BIM) or are based on geographic information systems in the district planning field. Their use simultaneously promotes and requires continuity in planning, constructing and operating building projects.

The aim of the energy efficiency-based balancing of districts is to compare the energy consumption before and after the implementation as well as to determine the realised energy savings. In addition, the planned savings should be compared with the actually measured energy consumption after the implementation in order to find out whether the planning was reliable and where there are deviations in the implementation, the efficiency of the energy supply or as a result of user influence.

By way of support, researchers are developing tools for balancing, new measurement technology, energy management and quality assurance systems, as well as models for energy and CO2 balancing. In doing so, they are also helping to improve cooperation between all stakeholders and are promoting the implementation of integral planning.

The Energiewendebauen research initiative supports the evaluation of energy-efficient demonstration projects both in individual buildings and urban districts. An important part of these projects is concerned with scientifically evaluating the implemented energy concept based on at least two years of measured data. As an aid, the research initiative provides monitoring guidelines that also deal with well-known software tools for data processing.

How economically viable are energy efficiency measures? This question is of considerable importance for the acceptance of energy efficiency investments. However, it is not so easy to find clear answers here. In practice, there are many different calculation methods and assumptions and data. The topic is complex because it involves different types of buildings or system types, different initial situations and utilisation scenarios, construction costs versus utilisation costs and a comprehensive view of all the costs incurred in the lifecycle of buildings or energy systems.

In addition to the costs, the yields and the benefits of buildings or energy efficiency-related modernisation measures are also of interest, again over time. A comparison of different alternatives, solely on a cost basis, presupposes functional equivalence. If this is not the case, for example due to varying comfort or user acceptance, then the benefits must also be included in the calculation in addition to the costs.

In many model projects, the cost-benefit ratio of the energy efficiency measures is analysed. However, no uniform assessment methodology has yet been established for this.