A wave of rising pupil numbers is rolling into the education system in Germany. For the school year 2022/23, the number of pupils starting school has risen by 5.2% compared to the previous year and has thus reached its highest level in 17 years. The federal states of Lower Saxony and Brandenburg are particularly affected, with growth rates of more than 8%. In Berlin, the increase is 6.6%. It is thus foreseeable that, with a few years' delay, the demand for school places at secondary schools will also increase considerably.1
Accordingly, there is not only a shortage of educational specialists, but also of school places. No surprise really, because in 2016/17 there were 2,800 fewer schools in Germany than 10 years earlier. A reaction to the low birth rate after the turn of the century. However, the decline in the number of schools is offset now and in the coming years by a steadily increasing need for new school space. In addition, there is a considerable renovation backlog at existing schools.
Investment in the construction of new school buildings
For Berlin alone, the development results in a shortage of about 20,000 school places in the current school year.2 New schools are urgently needed. Seven years ago, the Berlin Senate launched the Berlin School Construction Offensive (Berliner Schulbauoffensive) as a response to the development of pupil numbers and learning needs. The school construction offensive is intended to bundle all necessary measures and resources in order to guarantee sufficient school place capacities in Berlin in the future by extending existing school buildings and constructing new ones, reducing the renovation backlog and by accelerating the procedures for planned construction projects. The measures include the construction of at least 60 new schools. As a consequence, school construction expenditure has doubled in 5 years. This is a great economic potential, and from the point of view of the HVAC industry, it is not only the investment volume that is interesting, but also the definition of new spatial and energetic standards within the framework of the school construction offensive. Definitions that will also have an impact on the specifications for the construction of other public buildings.
Focus on room acoustics and energetic optimisation
When planning new schools, the Berlin Schulbauoffensive should not only take into account the creation of capacities but also the development of teaching structures from traditional frontal teaching to free, partner and group work. Flexible forms of teaching place new demands on school buildings and require classrooms to be adapted to a higher noise level. The new schools to be built should therefore also be oriented towards the latest standards in terms of pedagogy and architecture.
In order to achieve this, the Berlin Schulbauoffensive has published the set of rules "Standards for the Construction of New Schools" to give building contractors, architects and planning offices an orientation for the planning of new school buildings. According to these standards, "an energy supply concept must be drawn up for every new school building. In doing so, the most economical heat supply variant (including heat distribution and heating surfaces) with the highest possible proportion of renewable energies is to be worked out".3
Due to their high efficiency and diverse combination options with regenerative energy sources, heating-cooling ceilings are an ideal component for meeting the energy requirements of modern school buildings. Heating from the ceiling surface not only opens up architectural possibilities for large-area windows and flexible room design, but is also considered to be particularly health-friendly due to minimised air and dust turbulence. This is why ceiling heating systems are often used in hospitals. In summer, the system can be used for cooling.
In addition to the energetic upgrade, the improvement of room acoustics is of particular importance. With the intended modular and team-oriented teaching and learning processes in inclusive all-day schools, the room acoustics have a considerable influence on learning success. If the teacher is difficult to understand, more cognitive processes are required. An increased reverberation time also results in an increase in the general noise level. A high noise level creates the need to increase the volume of speech in order to make oneself understood (Lombard effect). Studies have shown that if the reverberation time is reduced to an optimal value, the overall noise level can be reduced by more than 10 dB.4
As a result, the construction standards of the Berlin School Construction Campaign call for a well-founded consideration of sound insulation and acoustic conditions by those involved in the planning process. Evidence must be provided in accordance with DIN 18041 and verified by measuring the reverberation time. DIN 18041 gives recommendations on the optimal reverberation time depending on the type of room use. For classrooms, it specifies a maximum reverberation time of 0.55 seconds, which can usually be achieved with sound-absorbing ceilings without additional measures.5
These acoustic specifications are a further reason for using heating-cooling ceilings in school buildings, because the thermally activated ceiling surfaces can also have a positive influence on the room acoustics at the same time, depending on the type of construction. A prime example is the use of BASWAphon Cool elements with BEKA capillary tube mats for the acoustically sensitive rehearsal and voice rooms of the Elbphilharmonie in Hamburg. But even thermally activated and perforated plasterboard improves the acoustic properties of a ceiling.
Heating-cooling ceilings for new school building in Berlin Tempelhof-Schöneberg
The advantages of heating-cooling ceilings for school buildings have already been taken into account in the new construction of the Gustav-Heinemann School, a integrated secondary. The new building is one of three pilot projects for the application of sustainable building criteria in school projects in Berlin and is expected to achieve silver certification according to the Sustainable Building Rating System (BNB) upon completion.
Here, perforated heating/cooling modules from ClimaDomo with integrated BEKA capillary tube mats are used, as they were in the new building of the AOK Bavaria.
The installation is carried out on standard CD drywall ceiling profiles. Required recesses for lamps, cables and pipelines are made possible by individually manufactured modules. The total area of the ceiling heating-cooling system in the new school building is 5,500 square metres.
The perforated heating-cooling ceiling was installed by Kaefer Construction GmbH Innenausbau Berlin. The air-conditioning technology was designed by KLIMA VOM FEINSTEN - Marko Augustat & Partner.
The school, designed by architects kklf. kleyer.koblitz.letzel.freivogel gesellschaft von architekten mbh, is scheduled to open in 2024.
1 aus Berliner Schulbauoffensive, Standards für den Neubau von Schulen: 2019, S.19 (in German)
2 https://buildingradar.com/de/construction-blog/schulbau-report-2020/ (in German, visited 13.02.2023)
3 https://www.destatis.de/DE/Presse/Pressemitteilungen/2022/11/PD22_473_211.html (in German visited 13.02.2023)
4 https://buildingradar.com/de/construction-blog/schulbau-report-2020/ (in German visited 13.02.2023)
5 Maue, Jürgen: Akustische Gestaltung von Klassenzimmern. In: Sicherheitsingenieur 06/2012, S.26-30 (in German)