Teaching about Climate-Efficient Buildings in the Context of Geographic Education for Sustainability

Abstract

The climate is changing worldwide and, with it, living conditions are changing to varying degrees. As a result, students need to be equipped with a wide range of competences in order to deal with the problems of climate change. In order to successfully acquire these competences, different methods are used in lesson planning. Therefore, in order to achieve the goal of raising awareness in Education for Sustainable Development, large-scale methodological learning form of the proposed model experiment will be used. For this purpose, it is necessary to first develop scientific knowledge about climate change and then present individual climate adaptation strategies using the example of climate-efficient buildings. The structure of the topic is grasped, and the didactically reduced core contents of the subject-specific scientific basics represent the specialist knowledge to be conveyed. This is followed by the construction of a self-designed model that is optimally adapted to the teaching of the subject knowledge. The subsequent series of measurements serves to evaluate the suitability of the model for the intended purpose of achieving a successful learning process under the aspects of quality criteria and practicability. The proposed model experiment has been found to be suitable and worthwhile for this purpose.

1. Introduction

The teaching of geography at the university level aims to equip students with the ability to think and act responsibly in order to secure a present and a future worth living. This subject enables students to understand the interrelationships of world events by showing the interactions between nature and society. The knowledge gained should be translated into spatially effective action. It focuses on the relationship between people and their environment. The aim of geography is to inspire students to act responsibly. Many phenomena cannot be grasped directly because human perception is quantitatively limited [1]. In order to grasp and understand them holistically, people try to focus their attention on the relevant aspects of these phenomena. However, the multiple interactions of reality make it difficult to focus. Therefore, reduced and specified images of reality have been used to reduce complexity. These reduced images are called models and allow access to different phenomena. Since “science […] can neither be taught nor learned without models” [2], they are, among other things, an essential part of geography education. With their help, new knowledge can be constructed.

One field of action for climate adaptation strategies is climate-efficient construction. In the future, not only people but also buildings will have to withstand the extreme adversities of climate change (e.g., heat, hail, heavy rain, floods, and storm events). This will require a wide range of structural adaptations [3].

In order to minimise society’s vulnerability to natural hazards, a basic awareness of the issue needs to be encouraged. As adaptation to change is usually associated with great efforts and additional costs, people need to recognise the urgency of this issue. This is the only way to create a willingness to adapt. As a basis for raising awareness, people need comprehensive and unbiased knowledge about the consequences of climate change and the likelihood of its occurrence. Building on this basic knowledge, a change in lifestyle can be tackled to address current key problems. It is the role of educational institutions to provide the necessary skills and knowledge. This is why it is so important to integrate the topic of individual climate adaptation strategies through climate-efficient construction into university teaching.

The concept presented here aims to show different ways of adapting to climate change at an individual level. In doing so, it opens the possibility of contributing to climate adaptation through the construction method of future buildings itself.

In addition to teaching technical and evaluation skills, the theme should also promote methodology and communication. As models are an excellent teaching method, a model experiment should ensure the targeted and successful acquisition of competences [4]. The aim is to design a model that illustrates climate-efficient buildings and makes the underlying mode of operation understandable. The quality of knowledge transfer will be significantly enhanced by the numerous advantages of model-based teaching and learning methods [5].

2. Climate-Efficient Building

Building their own home is an important goal for many people. Their wishes for their own four walls are often very different. However, they all have one thing in common: they want their home to be safe and sustainable. That is why buildings are always subjected to building regulations. These regulations are based on decades of experience and are constantly being updated. Guided by the realisation that climate change is an unavoidable problem for present and future generations, structural adaptation strategies to climate change are increasingly becoming the focus of building design. New buildings should be able to withstand external weather conditions and leave the indoor environment as unaffected as possible. However, as climate change with its extreme weather events is only becoming more frequent and severe in the latter half of this century, it is not possible to draw on decades of building experience. New climate-smart construction methods are constantly being developed based on predictions of future climate change. The suitability of a particular mitigation measure depends on the site-specific impact assessment used, the feasibility and effectiveness of the measure, and the financial outlay [6].

2.1. Adaptation to Heat

Adaptation to heat is a key area of mitigation. In order to keep the indoor environment comfortable for occupants even in the summer, different adaptation strategies are available to deal with rising outdoor temperatures. In principle, preventive measures that prevent buildings from heating up in the first place are the more cost-effective and environmentally friendly alternative to conventional cooling systems. However, as these measures only reduce heat that has already been generated, they are expensive in terms of energy consumption and cause additional anthropogenic heat flow outside the building. It is, therefore, important to integrate heat avoidance strategies into building design. One of the many possibilities is the greening of outdoor areas with natural shading elements. This includes the planting of different types of trees. When selecting tree species, care should be taken to ensure that they have a certain level of storm resistance, grow to an appropriate height, and are able to withstand temporary drought stress. Both trees and open green spaces contribute to pleasant outdoor temperatures in the summer. As plants derive their energy directly from solar radiation, they absorb it from their environment and convert it into latent heat. This removes heat from the surrounding air. The radiation absorbed by plants causes the water stored in them to evaporate and leave as water vapour. This process is called evaporative cooling. The cooled indoor air now has the potential to release heat to the environment via the exterior façade, ventilating the indoor spaces with cooler air and making it more comfortable to be outside [7,8].

A building’s façade can also contribute to reducing the thermal load of the interior. Influences can be exerted through the use of different building and insulation materials, colour design, and greening of the building façade.

When using building materials, a distinction must be made between building materials and insulation materials. Building materials are used to construct a building, while insulation materials are used to insulate the building. Basically, the thermal conductivity (λ), which indicates how well thermal energy can pass through a material, is central to the evaluation of building and insulation materials. It should be as low as possible to prevent heat entering a building in the summer and escaping in the winter. Building materials with low thermal conductivity serve to protect against both heat and cold [9]. These materials include wood (0.04–0.52 λ), clay (0.47–0.93 λ), and brick (0.50–1.4 λ). Other building materials that have high thermal conductivity and are, therefore, unsuitable for adaptation to climate change are sandstone (2.3–3.9 λ), cement (1.0–1.4 λ), and steel (48–50 λ) [10].

Another climate-friendly construction method is the use of insulation. There are three types of insulation: natural, mineral, and synthetic. Natural insulation materials are of organic origin and are made from renewable raw materials (hemp, wood fibres, and sheep’s wool). Mineral insulation materials (glass wool, mineral foam, and calcium silicate) are made from inorganic materials and usually have a natural fire protection function. Synthetic insulation materials include man-made polystyrene. The purpose of insulation materials is to reduce heat transfer through adjacent building components. Their insulating performance depends on the density of the material. Efficient building insulation is achieved with a low bulk density as the air-filled pores in the material used reduce its thermal conductivity. The best insulation performance is achieved with synthetically produced polystyrene (0.021–0.035 λ) [9,11].

Overall, efficient insulation measures are also increasingly contributing to climate protection as energy consumption is reduced due to lower heating requirements in the winter and reduced activation of technical cooling systems in the summer [11,12].

Another important parameter is the specific heat storage capacity (C = Joule/Kelvin × kg). It indicates how much heat energy a material can store. Basically, the higher the density of a building material is, the more heat it can store. For a building material to absorb heat from the interior and thus provide cooling, the temperature in the interior must be higher than the temperature of the adjacent wall surface. Particularly dense building materials, such as concrete (1000 C), plaster (1090 C), and cement (1130 C), help to cool the interior in hot summers. Solar radiation entering through windows can cause the interior to heat up considerably. This heat is absorbed by building materials, which have a high thermal storage capacity. The result is cooling and comfortable indoor temperatures. In order to effectively contribute to the reduction in heating costs during winter months, heat-storing building materials must be effectively combined with insulation materials; otherwise, heat will be released through the exterior wall into the cold environment due to temperature differences [11,12].

As a natural building material, wood is particularly suitable for climate-efficient construction because the production of this building material resource is sustainable and compatible with climate protection goals [13,14]. In addition, wood has the ability to sequester carbon. The cultivation of wood, therefore, removes CO₂ from the atmosphere. Another advantage of building with wood is that it can be recycled for energy. While the disposal of wood produces energy, the disposal of other building materials is usually associated with high energy consumption [14].

The choice of colour for roofs and façades can also counteract the heating of buildings. Due to the higher albedo of light colours, they reflect more solar radiation. The resulting lower absorption reduces the heating of building surfaces [15].

Another influence on indoor temperature is the number and distribution of windows. As glass is a building material that lets heat into the interior due to its conductivity, the design of windows should take into account shading elements and their exposure to the sun. The choice of glazing thickness can also have an impact on the indoor environment as the insulating effect of windows increases with the thickness of the glass. In double or triple glazing, there is an air gap between the panes. As air has a significantly lower thermal conductivity (0.0262 λ) than glass (0.76 λ), multiple glazing achieves better insulation [16].

Green façades and roofs are natural thermoregulators for the indoor environment. For extensive roof greening, perennials, sedums, herbs, and grasses are recommended as they are particularly suitable for growing on roofs due to their robustness [3]. The exterior façade, on the other hand, can be planted with a variety of soil-bound plants. A distinction is made between self-climbing plants, which colonise the exterior façade with their climbing roots, and scaffold climbers, which require a climbing aid. Ivy (Hedera helix) is a typical self-climbing plant, while Clematis vitalba is a well-known representative of scaffold climbers [17]. Both façade and roof greening act as natural insulation in the winter and can contribute to the cooling of the building façade. In the summer, however, greenery helps to reduce the thermal load of a building through its shading function. Other positive co-benefits of greening include evaporative cooling, which has a positive effect on the microclimate. It also acts as a buffer for rainwater, reducing the load on sewerage systems during heavy rain events [18].

2.2. Adapting to High Winds, Hail, and Snow

To prepare for increasingly severe wind events, a basic precaution is to close windows, gates, and doors tightly. This will prevent roofs from being lifted by wind. In addition, roofs can be reinforced with anchors, such as storm hooks or storm clips, and stabilised with extra weight. Hail resistance is achieved through the use of resistant materials. A green roof provides additional protection against hail damage. A more stable roof structure can be used to address the potential threat of snow loads in the winter [7].

2.3. Adaptation to Heavy Rainfall

As heavy rainfall events have increased in recent years due to climate change, it is necessary to adapt to the enormous destructive power of water. Water hazards can be reduced by building efficient rainwater and wastewater drainage systems. In addition, unsealed surfaces can positively influence the infiltration of surface water into subsoil. This can be achieved by using infiltrative surfaces (gravels, crushed stones, chippings, wood chips, grass paving, and paving with open joints). The creation of retention areas and swales to collect and infiltrate rainwater also protects buildings from water damage [13]. As an ecological adaptation strategy, it also has a positive effect on groundwater recharge and reduces pressure on public sewers. In addition to infiltration areas, purposefully created water areas (e.g., ponds) can absorb additional rainfall and, thus, reduce surface runoff. They also have a positive effect on evaporative cooling in the summer. Overall, near-natural strategies for water infiltration can be easily integrated into the visual design of outdoor facilities and are easy to maintain.

To protect basement spaces from soil moisture infiltration, the construction of a “white or black trough” is considered an effective adaptation strategy. A “black tank” is a thick bitumen coating to waterproof basement walls, while a “white tank” is made of concrete. It is less expensive but does not have the full watertightness of a “black tank”. In addition, pressure-tight basement windows can be chosen and lower building openings can be protected by roofing. To prevent backwater from the sewage system, backflow prevention devices, such as flaps or gates in the building drainage system, have proved effective. These allow water to flow away while preventing backwater [7].

The climate-efficient building concepts presented here show how wide the field of possible action is. Even if the implementation of preventive measures is initially costly, in the long term, they can protect buildings from larger and more expensive consequential damage. Depending on the local situation and the resulting effects of climate change, it is necessary to decide on a case-by-case basis which climate-efficient construction method should be used to protect a building.

3. Guiding Principles for Climate-Efficient Building

3.1. Models in Geography

Geography studies natural phenomena and processes. It uses models to explain them. A model (Latin: modulus) is an illustration of reality that shows its inner workings and functions on a different scale. As a reduced or enlarged image of reality, models have the characteristics of simplification and self-design [19]. Through the accentuated design of models, the section of reality relevant to a geographical question is represented in an idealised way. The function of models is to show the regularity of spatial conditions and processes. The simplified representation of complex reality serves to facilitate and guide the acquisition of knowledge in scientific issues. Models are considered key to understanding phenomena [19]. In geographic education at universities and schools, models are, therefore, primarily used as teaching and learning tools for the acquisition of specialised knowledge [2].

Geographical models can be divided into two- and three-dimensional representations. Two-dimensional models are iconic and symbolic representations (maps, profiles, and block diagrams). Three-dimensional models, on the other hand, are plastic reproductions [20] and are distinguished according to their intended use as visual, functional, working, planning, or experimental models [21]. The model on which a project is based is a three-dimensional experimental model in which the transitions to a geographical experiment are fluid. Model experiments are experiments in which geographical processes are simulated on an idealised model and analogies to reality are drawn [20]. With the help of a model, different variables can be systematically varied under controlled conditions in order to observe their influence on the facts and to derive explanations from them. The use of models in geography education follows the principle of operative visualisation and is an important part of the learning process. In operative visualisation, knowledge is gained through self-activity by imitating and visualising various geographical processes with the help of a model [19].

The use of models in geography leads to the acquisition of model competence. Students first learn to name the general properties of models as a basis, develop the object of a model, and understand its purpose. This competence is extended by the ability to use models to clarify scientific phenomena and questions and to establish analogies with reality. This is followed by testing models for adequacy of representation and correspondence to reality. A model critique takes place, which enables students to optimise their model in its problem definition and to extend it to subsequent thematically relevant scientific questions [2,4,5].

For the use of models to lead to the development of model literacy, several conditions must be met. On the one hand, models must correspond to reality in their essential characteristics. On the other hand, they must be simplified and visualised in a way that is appropriate for the target group. Despite being an idealised representation, however, they should represent relevant aspects of reality in a scientifically correct manner in order to enable truthful statements [22].

The use of models is particularly important for the development of scientific literacy. Scientific literacy enables students to apply acquired knowledge in everyday contexts in a problem-solving and reflective way. The transfer of knowledge from the classroom to the real world should be reflected in action-oriented behaviour and responsible participation in societal decision-making. Scientific literacy consists of three essential sub-competences. Students should be able to identify and explain scientific phenomena, plan appropriate investigations and experiments, and interpret the data obtained. Model experiments are particularly suitable for effectively training these sub-competences, as they provide not only conceptual expertise but also procedural knowledge about appropriate methods for gaining knowledge [23].

In addition to promoting scientific literacy, the use of models in geography has practical benefits. Models are often used when the real object is inaccessible or unavailable due to its spatial extent. Models are also used when reality does not allow individual variables to be tested in isolation in order to make their influence tangible. Models are, therefore, more manageable, available at any time, and suitable for targeted investigations.

3.2. Methodology

The presented project is part of the course “Applied Planning-Oriented Urban Climatology” and explicitly promotes social and methodological competence in addition to technical competence. Students are able to name the theoretical basics of urban climatology, apply them concretely to examples on site, master the necessary planning instruments, and are able to interpret the results collected by measurement and with the help of the described model itself with regard to their spatial effects and to present these findings.

The methodology for the implementation of the project is essentially based on the didactics of educational theory. The suitability of the course content is based on five central criteria: exemplarity, relevance to the present, relevance to the future, structure, and accessibility [22].

In the course of didactic reduction, the course content is narrowed down via structural reduction in such a way that the basic principles of the thermal effect of a respective adaptation strategy become clear. Elementary reduction, also called sectoral reduction, requires the presentation of the exclusively relevant part of the system. In particular, the use of models leads to a simplification of reality. During the construction of a model, it is analysed which real aspects should be included in the model and how. In the course design, it was decided not to include the sun’s path in the model used as this would not reduce or falsify the knowledge gained about the thermal influence of climate-efficient construction methods. The simulation of the sun’s path using a heat lamp would only complicate the model experiment manually and require additional time without adding any value to the knowledge gained. The interactions of solar radiation with other weather phenomena that occur in reality, such as clouds, rain, or hail, are also not taken into account by the model. This does not mean that the model does not recognise the existence of other weather influences, but these influences have been deliberately omitted for the sake of didactic reduction. By visualising only those aspects that are relevant to heat reduction, the influence of the test variables on the question becomes clearer and easier to understand. Through didactic reduction, the teaching content is optimally adapted to the essential elements necessary for knowledge acquisition. The key messages are presented to the students in a structured way and the learning process is focused [24].

In the course of didactic reduction to the elementary level, a detailed range of climate-efficient construction methods is not tested on the model. The teaching, therefore, follows the exemplary principle [25], in which the central learning content is conveyed through in-depth examination of an essential example. The primary learning product is the understanding of central system interrelationships that are detached from individual examples.

The simplifications made are also helpful and indispensable for lesson planning [26]. Similarly, “Cognitive Load Theory” explains that the capacity of a learner’s working memory is limited. After subtracting the load of the content and the demand on the learner’s capacity by using an external presentation of the learning content, what remains is the so-called “Germane Load”. This is the remaining capacity of the working memory available for the construction of new knowledge. To avoid overloading the working memory, it is therefore didactically sensible to avoid redundant content.

3.3. Structure of the Model

In addition to subject knowledge and model competence, geography teaches action competence. Action competence is one of the most important human abilities for dealing with central problems of our time (e.g., climate change) [27]. In order to enable students to develop individual action competence in the problem area of “climate change”, a tailor-made model experiment was designed. The aim of the model is to show the students their concrete options for action in the field of climate-efficient building for heat reduction. Two model houses were built to find out which climate-efficient building methods could best be represented in the model. These models were used to test adaptation strategies in terms of choices of building materials, insulation materials, glazing thickness, window position, greening, and façade colour. A series of measurements were taken to assess the suitability of the models and the selected climate-efficient construction methods for further use in the classroom.

The two model houses were made from a total of three kits from the “Walachia” and “Teifoc” companies. The first one is a wooden house from the “Walachia Vario kit” (Walachia Vario—Baukastenset; www.walchia.com; 33.00 EUR). The 72 parts of the kit can be used to assemble individual buildings. The components are beech logs with a diameter of 15 mm, which are available in different lengths (see Figure 1, left). The second model house was built from a kit from the company “Teifoc”, which is a brick house (TEI 4300—Fachwerkhaus—Multi Color; www.idealo.de; 38.00 EUR). The kit contains 200 parts, including roof and wall tiles, door, windows, trowel, mortar, and mortar tray. In addition, another basic kit was used to have more bricks available (see Figure 1, right; TEI 1000 Grundbaukausten Basic Set; www.ideolo.de; 35.00 EUR). In order to have as identical a measurement base as possible for data collection, the houses were not built according to the instructions provided. They are, therefore, self-made and have identical dimensions of 24.5 cm × 14.5 cm × 19 cm. For the wooden house, the logs were selected from the kit according to their length and joined together with wood glue. The brick house gets its stability from the hardening mortar. The roof was also built by the builder so that both model houses are identical. Similarly, the same elements were used in the selection of windows and doors to avoid differences in the size of the openings on the building façade. The materials used came from the “Teifoc kits”. As the windows consist only of a plastic frame without glass, a laminated plastic film was also inserted into the frame. The purpose of this is to realistically simulate window glass and prevent heat loss through the window openings. The adjustment of all components not considered as measured variables results in a congruent measurement base. The thermal deviations of the individual measurements shown are, therefore, exclusively due to the variation in the corresponding variables. The models that have been set up, thus, represent a basic framework that can be modified in many ways during an event through active modifications by the students under the aspect of constructing climate-efficient buildings. The roofs of the houses were simply placed on top of the walls and were not fixed with glue or mortar to make it easier to attach the test bodies. This makes it easy to add insulation to the interior walls, replace windowpanes, landscape the façade, and install temperature sensors inside.

In addition to the model houses, a 60 cm × 35 cm chipboard base was provided with an artificial lawn and a path of granite chippings. The base was also decorated with a white miniature wooden fence. The base is not necessary for data collection; the model houses could be used as a model experiment without it. However, because of its advantages, it was decided to build it. Firstly, a mark was made on the ground to indicate where the model houses should be placed for each measurement. This saves time during the lesson as the distance to the heat source does not have to be measured again. On the other hand, the attractive visual design helps to increase attention and motivation.

3.4. Data Collection

The model houses form the basis for determining the effectiveness of different climate change adaptation strategies. They form the basic framework that can be modified in a few steps in the course of constructing climate-efficient buildings. The models were used to determine the impact of different adaptation strategies by testing the relevant variables on them. As the field of action for Germany in the context of climate change is heat adaptation, climate-efficient construction methods for heat reduction were tested in the following way. The focus was on five adaptation strategies. The adaptation strategies investigated included the thermal influence of building materials, insulation materials, windows, greening measures, and façade colour. In all measurement series, the external factors were kept constant to ensure only variation in the variable to be tested. This was performed by maintaining a constant room temperature of 25.1 °C and the same distance and orientation of the heat source. The heat source used in the model experiment was an infrared lamp that simulates heating by solar radiation (Infraphil HP1540, Phillips; Hamburg, Germany; see Figure 2). It was placed in the middle of the model houses at a distance of 30 cm. The temperature at the outside wall was measured using a laser thermometer (Helect H-1020; www.ihelct.com). The room temperature inside the model houses was measured using a digital probe thermometer (Dostmann 30-1020-TFA; www.tfa-dostmann.de). In addition, pictures were taken with a thermal imaging camera (ICOdata SN:30320637; www.icodata.de). The measurement time per series was 20 min. The first measurement was taken before exposure to determine the baseline temperature of the models. The infrared lamp was then switched on and the next measurement was taken after four minutes. The interval between measurements was intended to represent some baseline warming due to irradiation since, in reality, buildings are also continuously irradiated. From this point on, data were collected at two-minute intervals. Within the entire measurement period, the effects of the thermal efficiency of the adaptation strategies could already be determined, so a longer exposure period was not used in order to protect the model houses from the enormous thermal stress caused by the infrared lamp. To ensure that the models had the same initial thermal conditions for each series of measurements, a fan was used to cool the models after each exposure period. Only when the initial temperatures of 25.1 °C on the outer wall and 24.8 °C in the interior had been reached was the next series of measurements started.

Measurement 1 investigated the thermal influence of the choice of building materials. Model houses No. 1 (timber house) and No. 2 (unpainted brick house) were used to determine the different heating requirements of wood and clay (see Figure 1). For this purpose, both model houses were exposed to the heat source for 20 min, and the temperatures on the outside wall and inside the houses were measured continuously. In addition, the values of the brick house served as a baseline for comparison with the other series of measurements as modifications with respect to the adaptation strategies were made to this model house.

Measurement 2 tested the effect of the building and the greening of the exterior. For this purpose, the roof of model house No. 2 was planted with garden cress (Lepidium sativum) and the outer façade was planted with summer jasmine (Solanum jasminoides). These were intended to correspond to a roof with marsh bluegrass (Sesleria caerulea) and a façade with ivy (Hedera helix) in reality. The original plants were deliberately not chosen because the ratio of the size of these plants to the model house is not optimal (see Figure 3, left). In a separate measurement, only the outdoor area was planted to capture the effect of natural shading elements. The false cypress (Chamaecyparis lawsoniana) used in the model corresponds to the planting of a Monterey cypress (Cupressus macrocarpa; see Figure 3, right) in reality. The model house with the greened exterior was also exposed to the heat source, and the temperature values were recorded so that the heat absorption of the houses with and without greening could be compared.

Measurement 3 was used to record the thermal effect of windows. Both different thicknesses of glazing and solar radiation on the façade were investigated. This was tested on model house no. 2 (brick house without paint). Firstly, single glazing was imitated by applying a laminated plastic film to the window frame. Triple glazing was imitated by applying two more laminated films. These allowed air gaps between the individual films required for multiple glazing. The model house was then exposed to a heat source in the same way as the previous series of measurements. A further measurement of the position of the window front was carried out with single glazing. Here, the back of the house was turned towards the heat source so that no window was exposed to the heat source. For both measurements, only the indoor temperature was measured as the influence of the glazing was only relevant to the indoor environment.

Measurement 4 tested different insulation materials. First, the interior of model house No. 2 was lined with polystyrene panels, and the house was irradiated again, with the temperatures recorded. The same measurements were then carried out with cork panels and foam padding in turn. All three insulation materials tested had a thickness of 0.5 cm. The thermal effect could, therefore, be attributed solely to the nature of the insulation material used and not to its thickness.

Measurement 5 determined the thermal effect of different façade paints. Originally, data collection was planned to be carried out with model house No. 2, which was to be painted differently on all four external walls (see Figure 4). However, as the position of the fenestration was found to have thermal influence during measurement 2, this factor could not be neglected. The uneven length of the external façades would also have meant that the measurements would not have been comparable. For this reason, only the façade of the model house was irradiated in all the series of measurements being carried out. As a result, the model house had to be repainted and dried after each series of measurements for each façade colour. The paints were applied from the lightest to the darkest colour to ensure complete coverage of the substrate. The façade colours to be tested were white, red, blue, and black. The white colour corresponds to the typical façade colour of many German houses, while the red colour corresponds to Swedish houses. In addition, a blue colour was chosen to represent Norwegian houses [28]. A black exterior façade was also tested to emphasise the albedo effect, especially in comparison to the white paint. The temperatures of the respective measurements were recorded for both the exterior wall and the interior.

4. Results of the Test Series

In order to test the suitability of using the model houses for teaching climate-efficient construction methods, the respective adaptation strategies were tested in separate series of measurements. It was investigated to what extent the effects of the thermal efficiency of different climate-efficient construction methods measured using the models correspond to reality and, thus, to theory. The results presented serve as a basis for the following discussion of effectiveness. The evaluation was carried out via a comparison with the baseline values measured using the unmodified model house No. 2. Without any modifications, this model house represents a house without a climate adaptation strategy. Only if the results obtained correspond to reality can correct acquisition of knowledge as a basis for action competence take place.

Measurement 1 was used to record the thermal effects of the choice of building materials. Figure 5a shows the temperature differences for timber and earth building materials. The brick house showed continuous heating of the outer wall and the interior during the irradiation period. After 20 min, the external wall temperature was 3.6 K higher and the internal temperature was 0.5 K higher than the wooden model.

In order to determine the effect of the climate-efficient design of the greening measures, the façade and the outdoor area were greened separately for measurement 2. This allowed a differentiated evaluation of the different greening measures. In addition, a comparison was made with the ungreened brick house. Figure 5b shows that both greening measures have a heat reducing effect. After 20 min of exposure, the temperature on the greened exterior wall was −2.5 K cooler than in the ungreened condition. With a temperature difference of 5.2 K, the green façade also had a reduced heat absorption effect compared to the ungreened brick house. Both the greening of the façade (−1.7 K) and the greening of the outdoor area (−2.0 K) resulted in more “comfortable” indoor temperatures than in the ungreened brick house.

The thermal influence of glazing thickness and window position was investigated in measurement 3. Figure 6a shows that triple glazing results in a −1.3 K lower indoor temperature compared to single glazing. The position of the window in relation to the heat source also results in a different temperature curve inside the building (Figure 6b). After 20 min of irradiation, a temperature of 30.7 °C was measured at the window front facing the sun, while the window front facing away from the sun caused the interior to heat up by −2.1 K to a temperature of less at 28.6 °C.

In measurement 4, the thermal insulation effect of different insulation materials was determined. Again, a comparison was made with the unmodified brick house to show the effect of the lack of insulation. Figure 7 shows that all the insulation materials used result in a reduction in the heating of the interior. At the same time, these materials increase the temperature of the external wall. The most effective insulation during the 20 min exposure period was achieved with foam, where the internal temperature was −2.2 K lower than inside the uninsulated house. The polystyrene insulation achieved a −2.0 K lower internal temperature, and the cork insulation achieved a −0.7 K lower internal temperature. The external wall warmed up significantly more than the uninsulated house, with +9.3 K for the foam insulation, +8.6 K for the polystyrene insulation, and +6.5 K for the cork insulation.

In measurement 5, the influence of different façade paints on the external wall and internal temperatures was determined. Figure 8a shows that the white paint has caused the lowest heating of the exterior wall at 35.2 °C after 20 min of exposure. The black façade, on the other hand, heated up the most at 52.1 °C. The red façade showed the second lowest heating at 37.3 °C. A similar picture was seen with the heating of the brick house without paint. The blue paint resulted in an external wall temperature of 40.8 °C.

The internal temperature was also influenced by the colour of the external façade. Figure 8b clearly shows that the interior temperature is positively influenced by the lighter colours in terms of lower heat absorption. After 20 min of exposure, the lowest indoor temperature of 29.0 °C was measured with the white paint. The black paint, on the other hand, induced an increased indoor temperature of 32.2 °C, while the red façade paint reached 30.4 °C and the blue façade paint reached 32.0 °C. The unpainted brick house had the lowest indoor temperature of 29.0 °C after 20 min of exposure. The unpainted brick house had an internal temperature of 30.7 °C. All the climate-efficient construction methods studied using the model houses show thermal effectiveness in reducing the heating of a building’s interior.

5. Discussion of the Results

The results of the measurements show that the thermal effectiveness of the adaptation strategies can be successfully reproduced with the self-built models. The data collected allow an evaluation of the efficiency of the different strategies and their suitability for thematic discussion in geography classes.

Measurement 1 (see Figure 5a) confirms the thermal effect of the choice of building materials. The measured data agree with the theory. As a building material, wood causes lower heat absorption on the outside wall and lower heat emission to the interior. Wood is, therefore, more suitable for thermal insulation than clay. This effect can be explained by the heat storage capacity of the building materials used. Because wood is less dense than clay, it stores less heat energy. This results in cooler temperatures on the outside of a wooden wall. The lower internal temperatures are due to thermal conductivity. This is significantly lower for wood (0.04–0.52 λ) than for clay blocks (0.50–1.4 λ). Due to the lower thermal conductivity, less of the thermal energy from the radiation source is conducted through the building material into the interior.

Measurement 2 (see Figure 5b) shows the cooling effect of the greening measures. The model experiment successfully shows that the greening measures lead to lower temperatures on the exterior wall and in the interior. This effect is mainly achieved through the shading function of the vegetation elements.

Measurement 3 (see Figure 6) confirms the climate-efficient effect achieved with increasing “glazing thickness”. The measurements show that “multiple glazing” is associated with higher insulation. Triple glazing, for example, transmits less heat into the interior than single glazing because the two air gaps between the three laminated films reduce the thermal conductivity of the pane (Figure 6a). The model can also be used to simulate the effect of window orientation (Figure 6b). A window facing a radiation source will increase the heating of the interior. On the other hand, if the window is turned away from the sun, lower indoor temperatures are achieved. This effect can be explained by the thermal conductivity of glass, which is much higher than that of bricks, thus favouring the transfer of thermal energy to the interior.

Measurement 4 (see Figure 7) shows the thermal performance of insulation materials. Compared to the uninsulated model house, all the insulated models have lower indoor temperatures. The thermal energy is first absorbed by the external wall. The insulation materials ensure that the thermal conduction from the external wall through the building materials to the interior is lower, so that the absorbed thermal energy accumulates in the external wall. This is confirmed by the measured external wall temperatures, which are significantly higher than that of the uninsulated model. However, a more detailed analysis of the insulation materials shows deviations from the theory. In reality, the most efficient insulation of the three materials tested is achieved by polystyrene, which has the lowest thermal conductivity of 0.035–0.05 λ. Cork (0.04–0.05 λ) and foam (0.06 λ) have higher thermal conductivity.

However, the data from the fourth measurement do not correspond to the expected results. They show that the best insulation is achieved with foam. A possible explanation for this discrepancy is that the insulation materials are all 0.5 cm thick. A possible source of error is, therefore, the composition of the materials. The insulation materials used in the model test, therefore, do not optimally reflect reality.

Measurement 5 (see Figure 8), on the other hand, confirms without contradiction the theoretical findings regarding the thermal effect of the façade paints. Lighter colours have a higher albedo than darker colours. The model experiment also shows that the white façade paint reflects the most heat energy from the radiation source and, therefore, has the lowest temperatures on the exterior wall (Figure 8a). At the same time, less heat is emitted into the interior due to lower heat absorption (Figure 8b). The black paint, on the other hand, increases the absorption of heat energy, resulting in higher temperatures on the exterior wall and in the interior. Comparing the red paint with the unpainted façade shows similar temperatures on the exterior wall and the interior. This is due to the natural reddish colour of the bricks, which results in a comparable albedo.

6. Educational Suitability of the Pilot Project

As it has already become clear, the topic of climate-efficient building is suitable for teaching individual and responsible action competence in the classroom. For a model to be suitable for classroom use, it must meet several criteria. One criterion is relevance [4,5]. The learning process must be clearly structured in order to achieve goal-oriented transfer of knowledge. This is achieved through didactic reduction. On the one hand, the model used must correspond to the learning requirements, while on the other hand, it must be reduced to the relevant learning content [2]. The constructed model fulfils the criterion of fit. In order to only teach adaptation strategies in the area of heat dissipation, only a small part of the Earth’s climate system is modelled. Heat radiation represents solar radiation, while other weather phenomena, such as rain, snow, hail, and wind, are difficult to model. This reduces the complexity of the facts to be conveyed.

Another criterion is realism [27]. Despite the simplified representation due to didactic reduction, the model used must contain the essential characteristics of the original source [2]. This criterion is met because the model has many analogies to reality. All the model houses built in this study realistically represent the aspects relevant to the understanding of the subject. Both the materials used for construction (bricks, wood, mortar, etc.) and the variables to be tested (glass, plants, paints, etc.) represent the originals adequately and functionally.

Although a model represents a problem in an artificial and simplified way, it must be accurate [4,5]. The knowledge gained from the model must correspond to the recognised and currently valid state of the science [2]. This criterion is not fully met. The data from measurements 1, 2, 3, and 5 correctly reflect the thermal efficiency of the underlying climate-efficient construction methods. Only the fourth set of measurements shows deviations. It is not possible here to rank the insulation materials in terms of their theoretical thermal performance. Nevertheless, the measurements prove that insulation is a climate-efficient adaptation strategy as it leads to lower indoor temperatures compared to uninsulated construction. Thus, the general function of insulation can be illustrated using the models. In order to present only technically correct results to students in a lecture, the fourth measurement has to be adjusted. Since the insulation materials tested (polystyrene, foam, and cork) do not optimally represent reality, no differentiation can be made with regard to the efficiency of thermal insulation. Nevertheless, the fourth measurement shows the general advantage of insulation measures. The model experiment should, therefore, be limited to a comparison between an uninsulated and an insulated house. Polystyrene is suitable as a representative insulation material because it successfully demonstrates thermal spread in the series of measurements and achieves one of the best insulation performances in reality.

In addition to the criteria that the models meet, there are other advantages. The glue and mortar construction method gives the houses a certain stability. This makes it possible to act independently and make changes without fear of contact with the models [2]. In addition, the model experiment can be classified as harmless as no chemicals or dangerous tools are used. Only the heat lamp is a minor hazard due to the heat it generates. Before the model experiment is carried out, a warning should be given about careful handling of the lamp. Another advantage is the attractive visual design, which attracts attention. This also increases motivation and willingness to learn. The visual presentation and the special nature of the model experiment also lead to a better anchoring of what has been learned in the long-term memory.

However, for all the benefits outlined above, there are a number of implementation issues that need to be considered to ensure a smooth process. These issues must be anticipated and taken into account in the design decisions. Firstly, thermal imaging has proven to be an inappropriate measurement method. Thermal imaging tends to show temperature differences throughout a building. Thermal weak points, where heat exchange is facilitated, can therefore be identified by the colouration of the thermal images taken. However, due to the small size of the models and the intense radiation from the infrared lamp, a thermal imaging camera cannot record differentiated temperatures within the model houses. The images only show the temperature difference between the model houses and the ambient temperature. This is not meaningful.

Another disadvantage of the model experiment is the cooling time of the model houses between the measurements before and after a modification is made. However, this is necessary to ensure a consistent measurement base. As the aim is to teach students about constructing climate-efficient buildings in about 90 min, the time available is limited. Therefore, it is necessary to work on individual adaptation strategies in the social form of group work with subsequent presentation of the results in a plenary session. The resulting disadvantage is the quantitative need for many model houses to provide each group with an independent working base. This requires a lot of preparation on the part of the teacher as several model houses have to be built. However, such model houses are very strong and stable and can be used as often as required; thus, it is a one-off production process.

All in all, the advantages outweigh the disadvantages, and the use of models in geography lessons can be considered useful and appropriate [2,4,5].

7. Conclusions

The educational project presented was dedicated to the challenge of constructing a model for use in the classroom that represents an ideal method for teaching action competence in dealing with the consequences of climate change. Spatially effective action competence is acquired on the basis of the question on how to deal with climate-efficient building methods in a sustainable way. In order to make the topic comprehensible and to facilitate the learning process, reality was simulated in a simplified form by means of a model. To enable the students to work with the model in an intensive and independent way, it was necessary to construct a model on which various experiments could be carried out. The model should be suitable for action-oriented teaching.

For the project, two model houses were built that could be modified by different variables. The variables represented different climate-efficient construction methods. In order to create an identical measurement base, the building dimensions, façade openings, and roof truss had to be completely constructed by the students themselves. Only in this way could the thermal effects shown be reliably attributed to the variations in the variables. Even the climate-efficient construction methods initially considered suitable for the model experiment did not fully confirm their thermal efficiency in theory. This was shown by the series of measurements carried out on the insulation materials. The reason for this was that the model variables were not sufficiently similar to reality. In addition, the enormous amount of time required to fully verify all of the pre-defined climate-efficient construction methods became apparent, and this had to be taken into account in the implementation planning.

In conclusion, the project results show in detail that the didactic use of the model houses to convey knowledge about individual climate adaptation strategies by means of climate-efficient construction methods can be confirmed to be extremely economical, supportive of the learning process, and efficient. As a teaching method that is beneficial in terms of teaching and learning, it should, therefore, not be dispensed with despite the cost of production.

The content of the individual climate adaptation strategies for constructing climate-efficient buildings was didactically reduced, and the learning objectives to be achieved were defined. On the basis of the didactic concept, a suitable methodical structure for the learning process was selected, with the model experiment being the central focus. Due to the time frame of 90 min and the time-intensive model experiment, the social form of group work with subsequent presentation of the results in a plenum proved to be appropriate. In this way, all students were able to gain knowledge about several climate-efficient construction methods. The small group format meant that the model houses were needed several times, depending on the number of students.

However, it is questionable whether every lecturer is willing to build the required number of model houses, despite the obvious benefits. In order to avoid the production effort of individual lecturers and to gain further benefits from the idea of such a model experiment, the model work can be planned as a large-scale methodological learning form during a project week. A project on individual climate adaptation strategies through constructing climate-efficient buildings could be designed in such a way that students go through the whole modelling process independently. The lecturer acts only as a supportive contact person and coordinator, who defines the learning framework in advance within which everyone can develop freely. At the beginning of the project week, everyone familiarises themselves with the topic and plans and builds their model houses independently. This is followed by model experiments and data analysis. Finally, the results are processed and presented. In addition to the above-mentioned advantages of the model experiment, a project week can explicitly promote independent work, self-organisation, and perseverance on the part of the students.