2.2.1. Usability
Designers strive to develop products that are simple and cost-effective to use. This is called “usability” or “ease of use” [
15]. The ISO 9241-11 standard (ISO, 1998) defines usability as “the extent to which designated users can use a product in a particular context to achieve specific objectives with satisfaction, efficiency, and effectiveness” [
16]. Usability can be applied in different contexts, including building designs, which ideally require a user-friendly and efficient environment. For an efficient building design, economic, functional, and aesthetic factors must be taken into account [
15].
School buildings are where students and teachers interact, while staff, parents, and other personnel strive to create an environment that is conducive to learning and guidance. The size and layout of a structure vary according to its purpose. However, designing a school building requires the consideration of many factors to achieve usability within the building, including safety, wayfinding, thermal comfort, social interaction, orientation, flexibility, acoustic comfort, and connectivity between spaces [
17].
2.2.2. Flexibility and Adaptability
The field of building design has undergone significant changes due to rapid advancements in technology, requiring architects to adapt to the demands of people and utilize the benefits of the latest technology. According to one study, building designs prioritize flexibility over rigid functional ordering and hierarchical arrangements. Therefore, designers use adaptable designs for various purposes. The architect Aldo van Eyck has cautioned against a “one-size-fits-all” approach to design, stating that one design may not be suitable for all users [
18].
New building technologies, such as the use of steel and reinforced concrete materials, have introduced the concept of flexibility to building designs. Architects are now embracing the idea of a free plan [
18]. However, defining and characterizing flexibility in architectural design is challenging since it involves integrating people, functions, and space. To achieve flexibility, an optimal correlation and the organization of areas are crucial in contemporary architecture. Moreover, flexibility is not achieved through reciprocal spatial arrangements but by introducing variability in the interconnections across functions [
18].
The application of flexibility in architectural design can be broadly categorized into functional and adaptable paradigms. However, adaptable flexibility offers more freedom than functional flexibility. For instance, a single space may need to accommodate up to three distinct functions because of variations in ergonomic design requirements. The achievement of adaptability and appropriateness is essential in a flexible space [
18,
19].
2.2.3. Cost-Effective School Design
Research has shown various ways to reduce construction costs. One major principle of sustainable development is to create cost-effective building designs and construction methods [
20]. In school construction, architects and designers have made efforts to reduce costs so that more schools can be built. One effective approach uses local materials and techniques. For instance, architects John McAslan, Parterres, and Arup employed this methodology to construct a low-cost school building in Malawi [
21].
Many new building technologies are more cost-effective compared to traditional methods [
22]. One area of focus for researchers is the selection of optimal building materials for school buildings. In a study aimed at minimizing the construction costs of public schools in Iraq, the researchers used the computer program Analytical Hierarchy Process to select appropriate materials for exterior walls. They compared four building systems: a brick cavity wall system, a lightweight block wall system, a precast concrete wall panel, and a metal-framed sandwich panel. They assessed nine critical attributes—durability, safety, maintainability, flexibility, availability of skilled workers, regional materials, waste management, thermal properties, and acoustic properties. The brick cavity wall system received an excellent rating compared to the other materials [
23].
The use-efficiency method has been applied to the study of primary schools in India to reassess the cost of building a conducive learning environment [
24,
25]. The aim was to increase the utilization of classroom assets from 0.51 to 0.85, which would lead to a 40% reduction in the expenses associated with informal learning in the classroom. This can be quantified using the “Utilization Efficiency” formula, defined as follows:
T classroom is the amount of time spent in classroom spaces. This is the total number of hours classrooms are used for teaching and learning over a specific period.
is the amount of time the school is open. This is the total number of hours the school is operational over the same period. The formula calculates the percentage of school time effectively used for classroom activities. Higher utilization efficiency indicates better utilization of classroom spaces, leading to enhanced cost-efficiency. The goal of this formula is to maximize the effective use of classroom spaces relative to the total available school time, thereby enhancing the cost-efficiency of the learning environment [
24]. However, the study identified some challenges, such as an uncomfortable environment on hot days and poor movement and circulation, which required implementing a terracing area. As a result, the conversion of two classrooms into outdoor terraces reduced the number of classes from five to three. The study concluded that this change resulted in a decrease in classroom demand, optimization of space utilization, and increased acceptance of outdoor learning activities.
Additionally, Srivastava showcased alternative school design layouts that could be 20% more cost effective than existing learning environments. These alternatives involved adjustments to construction and design criteria and implementing prefabrication techniques for specific building components. To achieve a low-cost construction plan, empty areas need to be eliminated throughout a school’s design. Therefore, the building’s spaces and functions require high flexibility and adaptability. The designer’s primary responsibility is to prioritize a connection between the learning process and the available resources [
24].
Reducing energy consumption is effective at minimizing the usage cost of buildings. One approach is by strategically designing corridors. Zhang et al. (2017) explored the design of corridors in a cold environment in China to conserve energy within the building. They focused on three types of corridors—double-load, single-load closed, and single-load open—and evaluated them based on six main criteria: shape and direction, temperature control, components of the opaque cover, infiltration, glazing, and ventilation. To conduct the evaluation, the researchers used a computer program called Design Builder. The study concluded that the single-load open corridor is the best-quality design for energy savings compared to the other two forms of design [
11].
A courtyard is an essential architectural element that contributes to a building’s energy efficiency. In an essential study conducted in Kirkuk, Iraq (Najib and Ekici, 2022), researchers explored how the width and orientation of courtyards affected energy consumption in eco-friendly building designs. The study used computer programs such as Revit and Green Building Studio to simulate courtyards according to different criteria and compare the variation in cooling and heating within the building. The analysis produced various proposals confirming that the width and orientation of a courtyard can significantly impact the heating and cooling of a building. Increasing the width of the courtyard can increase energy consumption because of the larger proportion of the build-up area. Najib and Ekici also concluded that areas facing west and east require more thermal energy during the winter, but in the summer, the situation is reversed, resulting in less consumption of cooling energy [
26].
Reducing the costs associated with building schools is crucial for low-income countries. Many studies have been conducted to analyze the strategies used by countries to minimize expenses while ensuring a user-friendly design for modern educational systems. For example, Pereira et al. (2018) examined the analytical design methodologies used to assess the learning environment in the early design phase for public schools in Brazil. Their study aimed to evaluate and enhance the design layout by employing a systematic design process and specifying design parameters. They presented three analytical methodologies for educational buildings: a design quality indicator, the multi-criteria optimization of environmental comfort evaluation method for school buildings, and a comparative floor-plan analysis. The study examined twenty school design layouts using the suggestions from a comparative floor-plan analysis and the foundation for educational development. Pereira et al. (2018) revealed the need to employ a well-designed analytical approach and utilize concrete-based knowledge to provide an effective learning environment [
27].
According to Sureshkumar et al. (2018), constructing a school building at a reduced cost cannot be accomplished by solely relying on low-cost materials. Other factors play a role in a cost reduction assessment, such as the condition of the site, the shape and size of the layout of classrooms, the height of the building, the amount of decorations, and the use of lower-cost local materials. To manage these economic criteria, certain factors need to be considered, such as the availability of natural daylight and permanent ventilation in classrooms and bathrooms, the durability of the materials, maintenance requirements, the central plant area, thermal insulation, fire safety, strength, stability, comfort, and convenience [
28].
2.2.4. Sustainable and Green Building Practices
Sustainable and green building practices are essential for modern school construction, focusing on reducing environmental impact, promoting resource efficiency, and ensuring long-term ecological balance. These practices include using recycled materials like Fiber Reinforced Recycled Aggregate Concrete (FRAC), which enhances the mechanical properties of concrete while recycling construction waste [
29]. Additionally, optimizing energy efficiency through strategies such as natural ventilation and daylighting significantly reduces energy consumption and enhances the learning environment. Green buildings provide multifaceted benefits, including improved environmental performance, economic savings, and enhanced health outcomes for occupants [
30]. Implementing green building standards and certification systems, such as LEED and BREEAM, provides verification of the sustainability of a project and offers various economic and environmental benefits. These benefits include significant reductions in energy, carbon, water, and waste, resulting in cost savings and increased building value [
31]. By incorporating these sustainable and green building practices into school design, we can create educational environments that are not only cost-effective but also environmentally responsible and conducive to long-term ecological balance. These strategies ensure that schools can provide healthy, efficient, and adaptable spaces that support the well-being and academic success of students and staff.