Retrofitting for Energy Efficiency Improvement Using Kinetic Façades in Residential Buildings: A Case Study from Saudi Arabia

Abstract

Kinetic façades represent a climate-responsive design solution that improves building adaptability by responding to seasonal needs such as daylighting and shading. They offer an attractive retrofit strategy that improves both the esthetics and environmental performance of buildings. This study investigated the integration of an origami-inspired kinetic façade into a student dormitory building located in Dhahran, Saudi Arabia. Using numerical simulations, 35 façade configurations were analyzed under varying conditions of façade orientations, closure ratios (from 5% to 95%), and cavity depths (from 20 cm to 100 cm). The findings highlight the critical impact of kinetic façade design characteristics on daylight availability and solar exposure and the required trade-off between these two variables. In this context, this study observed that at higher façade closure ratios, increasing cavity depth could effectively mitigate daylight reduction by promoting reflected daylight penetration inside the cavity. As for heat gains and cooling load reduction, mid-range façade closure, 50 cm in this study, achieved balanced performance across the three examined orientations. However, the southern façade showed slightly higher efficiency compared to the eastern and western façades, which achieved lower cooling reductions and showed a similar UDI compromise. Thus, a dynamic façade operation is recommended, where higher closure ratios could be applied during peak solar hours on the east in the morning and the west in the afternoon to maximize cooling savings, while moderate closure ratios can be maintained on the south to preserve daylight. Future work should incorporate real-time climatic data and smart control technologies to further optimize kinetic façade performance.

1. Introduction

Global warming, mainly caused by the buildup of greenhouse gases (GHGs) in the atmosphere, has resulted in a notable rise in the Earth’s average surface temperature. Since 1880, global temperatures have climbed by roughly 1 °C and are expected to increase by about 1.5 °C by 2050, reaching between 2 °C and 4 °C by the year 2100 [1]. These changes disrupt ecosystems and poses serious challenges to human settlements, mainly in densely populated urban environments, where maintaining thermal comfort is essential for human health and productivity [2]. Buildings are a crucial focus of mitigation efforts, as they account for approximately 36% of global energy consumption and 40% of global carbon emissions [3]. The residential sector alone is responsible for about 25% of global energy use [4]. As global temperatures continue to rise, energy demand for cooling in buildings is expected to surge, particularly in hot regions. Increased heat stress due to rising global temperatures exacerbates the demand for cooling systems, leading to higher energy consumption and an increase in carbon emissions, further fueling the cycle of climate change [5].

The utilization of building design to improve energy efficiency and thermal comfort depends on proper awareness of the local climate including the need for proper solar control. This holds true for both new and existing buildings, particularly when considering that more than 70% of the buildings currently in use are expected to remain operational by 2050. Energy retrofitting refers to the process of upgrading the existing buildings to improve their energy efficiency. It typically involves implementing a range of strategies focused on the building envelope, which plays a crucial role in reducing energy consumption and maintaining users’ thermal comfort. These strategies may include improving insulation, upgrading windows, and integrating additional systems such as double skin façades or solar panels. Furthermore, energy retrofitting can involve optimizing building automation and control systems to ensure more effective energy management [6]. Several design solutions have been proposed and investigated in this regard including kinetic façade systems. Kinetic façades are adaptable architectural systems that can be incorporated into the envelope of new or renovated buildings to enhance both visual appeal and environmental efficiency.

Accordingly, this study investigates the effect of integrating an origami-based kinetic façade into a student dormitory building in Dhahran, Saudi Arabia, on daylighting levels and cooling loads. A parametric numerical simulation was conducted to evaluate various façade configurations with closure ratios ranging from 5% to 95%, and façade cavity depth, ranging from 20 cm to 100 cm. By improving indoor environmental conditions through a façade system that has an open-close mechanism, this design approach aims to reduce the reliance on excessive air conditioning for cooling load while maximizing daylight penetration into the building.

2. Literature Review

In recent years, Saudi Arabia has witnessed substantial growth in both its population and economy. The population increased to over 35 million by mid-2024 with an annual growth rate of 4.7% [7]. Energy demand has increased dramatically as a result of this economic and demographic expansion, continuous urbanization, and rising living standards. Although Saudi Arabia is striving to achieve its 2030 target of sourcing at least 50% of its energy from renewable sources, the country’s main reliance is on fossil fuels. One major problem with this growing demand is the low energy efficiency of many residential buildings and apartments in Saudi Arabia. Before the current energy efficiency regulations took effect, a significant portion of the residential buildings, about 539,899 units, were constructed between 1984 and 2014. These buildings are between ten and thirty years old, which requires a major retrofit plan to upgrade them for better energy efficiency [8]. One promising approach in this context is façade retrofitting using dynamic systems such as kinetic façades.

The integration of dynamic structures for climate-responsive control has gained increasing attention in recent research. For instance, Minelli et al. [9] developed an early prototype of a modular, sun-tracking photovoltaic (PV) system designed for large-scale urban applications. The system’s flower-inspired geometry, with movable, petal-like elements, enhances electricity generation compared to fixed PV panels while simultaneously providing shading in densely populated areas. Similarly, kinetic façades in buildings feature dynamic components, such as movable panels or louvers, that actively respond to environmental conditions like sunlight and wind and regulate indoor environmental quality. Unlike double skin façades and other environmental control passive systems, it is essential for kinetic façades to employ mechanical systems to control and adapt the movable elements [10]. Originating from traditional Japanese paper folding, origami principles have influenced dynamic and deployable systems in biomedical, aerospace, and architectural applications due to their modular adaptability and transformative capabilities. These qualities can be harnessed for solar management and daylight optimization [11]. Kinetic façades could be integrated into existing buildings as a retrofit strategy to enhance environmental performance, occupant comfort, and architectural design of buildings. This process typically involves installing a secondary skin composed of operable panels that are mounted on lightweight structural frames attached to the building’s primary envelope. This system is operated through control mechanisms that can be automated using environmental sensors [6,10].

The integration of kinetic façades into the building envelope not only serves as a thermal barrier but also improves visual esthetics. Kinetic façade could considerably improve architectural esthetics by including rhythmic motion, varying patterns, shifting transparency, and manipulation of exterior lighting and shadow design. This engages users with their urban context and improves users experience and comfort [12]. This could be enhanced by the incorporation of smart materials, which opens new design possibilities in which functionality and esthetics complement one another [13]. Biomimetic façade techniques have also expanded the visual and functional language of kinetic façades. Biomimetic kinetic designs go beyond traditional architectural expression by drawing inspiration from nature including plant morphologies. The constant evolution of these façades makes them fascinating visual features in their surroundings [14]. Kinetic façades could also be designed based on geometrical patterns using repetitions and rotational movement, which provide sophisticated visual dynamics including basic origami fold techniques [15,16,17,18,19]. Figure 1 illustrates some examples in this regard.

A thorough review of the literature shows that kinetic façade designs have advanced significantly, as they could improve daylight performance, thermal comfort, and energy efficiency across various climate zones (Table 1). Several advanced methods, such as biomimetic and origami-inspired designs, have been extensively studied and shown to adapt to changing environmental conditions. Several studies have explored kinetic façade use in hot climates, emphasizing adaptability and environmental performance enhancement in various architectural contexts. A recurring theme in the literature is the diversity of kinetic façade operation mechanisms and their impact on energy consumption and daylight modulation. Building materials also emerge as critical parameters influencing façade performance. Materials selection should consider not only thermal properties, e.g., emissivity, conductivity, but also durability and visual impact. For example, Eddine [17] investigated methods to enhance the performance of deployable building façades using biomimetic strategies tailored for efficient thermal and environmental response. Similarly, Fraternali et al. [18] focused on developing and evaluating dynamic origami-inspired solar devices to improve energy harvesting within traditional Mashrabiya systems.

Attia [20] conducted an in-depth case study evaluating adaptive façade systems in the United Arab Emirates, highlighting their suitability for hot climates. Yunitsyna and Sulaj [23] aimed to optimize daylight in south-facing classrooms by implementing a biomimicry-inspired kinetic façade shading system that addressed both environmental and functional goals in educational spaces. Meloni et al. [24] also explored origami-based designs, developing an adaptive façade to reduce reflected solar radiation in outdoor urban environments, and improve pedestrian comfort. In the context of school environments, Elfeky et al. [25] proposed origami-inspired interactive kinetic façades that respond to students’ positions to improve their visual comfort. Together, these studies demonstrate the growing interest in adaptive, responsive, and bio-inspired façade technologies aimed at improving energy efficiency, visual comfort, and environmental performance in buildings. Finally, Radhi et al. [26] examined multi-façade systems designed to reduce cooling energy in the hot climate of the UAE. They found that increasing cavity depth from 0.5 m to 1.2 m could reduce annual energy usage by 13% by lowering conductive heat transfer and increasing airflow.

Overall, these studies highlighted the potential of façade geometry to enhance seasonal adaptability and daylight performance. However, there remains a need for thorough investigation of kinetic façade integration into existing structures under extreme hot-climate conditions, such as those in Saudi Arabia. This includes the investigation of the trade-offs between daylight penetration and thermal regulation. Therefore, this study extends previous research by considering the severe hot climatic conditions of Saudi Arabia through parametric simulations to evaluate the interplay between geometry and cavity design to improve energy efficiency. It investigates how incorporating an origami-inspired kinetic façade into residential buildings located in the hot climate of Saudi Arabia could influence both daylight availability and cooling loads. A parametric simulation approach was employed to explore various scenarios of façade closure ratios, from 5% to 95%, and cavity depths, between 20 cm and 100 cm. The goal of this open-close façade system is to enhance indoor environmental quality by optimizing daylight access while reducing reliance on air conditioning for cooling.

Table 1. A summary of the reviewed literature on kinetic façades.

Ref.	Year	Climate	Façade Type	Analysis Methods	Key Findings
Hosseini et al. [14]	2021	Hot desert, Iran	Multilayered biomimetic kinetic shading system	Simulation using Rhino, Grasshopper, and Diva	Improved Spatial Daylight Autonomy (sDA) and UDI through layered transformations.
Yunitsyna & Sulaj [23]	2025	Mediterranean, Albania	Biomimicry-based hexagonal modular kinetic façade	Simulation using ClimateStudio and users’ survey	Glare reduction by up to 94%
Ming et al. [27]	2025	Temperate, London	Adaptive fenestration thermotropic and transparent insulation	Modeling with experimental validation	Summer heat gain cut by about 30% and winter loss by about 20%
Naeem et al. [28]	2024	Hot desert, Egypt	Horizontally rotating sunscreen actuated by Shape Memory Alloy	Full scale testing and simulation using Rhino and Honeybee	Up to 55% cooling load reduction with no mechanical systems.
Mangkuto et al. [29]	2022	Tropical, Indonesia	Internal horizontal adaptive shading with slat angle variation	Simulation using Rhino, Grasshopper, and Diva, and Colibri toolbox for optimization	Adaptive slats significantly improved daylight autonomy and reduced glare probability to less than 6%
Talaei et al. [30]	2022	Cold semi-arid, Iran	User-responsive microalgae bioreactor	Experimental testing and EnergyPlus simulation	Summer cooling savings of about 30%
Besbas et al. [31]	2022	Hot arid, Algeria	Parametric kinetic shading module with rotating hexagonal cells	Simulation using Rhino, Grasshopper, Ladybug, Honeybee, and Octopus	Energy Use Intensity (EUI) reduction by 14.1%, improved UDI from 35.2% to 78.3%
Berge et al. [32]	2015	Cold, Sweden	Adaptive pressure-controlled opaque wall system	Laboratory measurement and Energy simulation	Adaptive U-value façade reduced weighted energy demand by up to 20%
Wanas et al. [33]	2015	Hot arid, Egypt	Horizontal louvers with kinetic movement	Simulation (Rhino, Grasshopper, Diva, and Radiance)	Best-case kinetic louvers increased day-lit zone from 53% to 63%

Table 1. A summary of the reviewed literature on kinetic façades.

Ref.	Year	Climate	Façade Type	Analysis Methods	Key Findings
Hosseini et al. [14]	2021	Hot desert, Iran	Multilayered biomimetic kinetic shading system	Simulation using Rhino, Grasshopper, and Diva	Improved Spatial Daylight Autonomy (sDA) and UDI through layered transformations.
Yunitsyna & Sulaj [23]	2025	Mediterranean, Albania	Biomimicry-based hexagonal modular kinetic façade	Simulation using ClimateStudio and users’ survey	Glare reduction by up to 94%
Ming et al. [27]	2025	Temperate, London	Adaptive fenestration thermotropic and transparent insulation	Modeling with experimental validation	Summer heat gain cut by about 30% and winter loss by about 20%
Naeem et al. [28]	2024	Hot desert, Egypt	Horizontally rotating sunscreen actuated by Shape Memory Alloy	Full scale testing and simulation using Rhino and Honeybee	Up to 55% cooling load reduction with no mechanical systems.
Mangkuto et al. [29]	2022	Tropical, Indonesia	Internal horizontal adaptive shading with slat angle variation	Simulation using Rhino, Grasshopper, and Diva, and Colibri toolbox for optimization	Adaptive slats significantly improved daylight autonomy and reduced glare probability to less than 6%
Talaei et al. [30]	2022	Cold semi-arid, Iran	User-responsive microalgae bioreactor	Experimental testing and EnergyPlus simulation	Summer cooling savings of about 30%
Besbas et al. [31]	2022	Hot arid, Algeria	Parametric kinetic shading module with rotating hexagonal cells	Simulation using Rhino, Grasshopper, Ladybug, Honeybee, and Octopus	Energy Use Intensity (EUI) reduction by 14.1%, improved UDI from 35.2% to 78.3%
Berge et al. [32]	2015	Cold, Sweden	Adaptive pressure-controlled opaque wall system	Laboratory measurement and Energy simulation	Adaptive U-value façade reduced weighted energy demand by up to 20%
Wanas et al. [33]	2015	Hot arid, Egypt	Horizontal louvers with kinetic movement	Simulation (Rhino, Grasshopper, Diva, and Radiance)	Best-case kinetic louvers increased day-lit zone from 53% to 63%

3. Materials and Methods

This study investigates the influence of different kinetic façade configurations on daylight performance and cooling loads in the case study building. The research workflow is illustrated in Figure 2.

3.1. Climatic Conditions and Building Description

This study examines a student dormitory building at King Fahd University of Petroleum and Minerals (KFUPM), located in Dhahran, Eastern Province, Saudi Arabia, as a case study. Dhahran (latitude 26.27° and longitude 50.17°) represents one of the main climatic categories in Saudi Arabia [34], namely the hot desert climate zone, characterized by long, hot, and arid summers and cool, dry winters (

Table 2. Average climatic conditions of Dhahran, Saudi Arabia [35].

Parameter	Summer	Winter
Average Dry Bulb Temperature	36.5 °C	17.7 °C
High Dry Bulb Temperature	43.7 °C	23.3 °C
Low Dry Bulb Temperature	29.3 °C	12.0 °C
Relative Humidity	34.7%	63.7%
Precipitation	2.9 mm	14.3 mm

). The examined building is a typical KFUPM student dormitory consisting of three floors, each measuring 1211 m² in area and 2.9 m in height. It features an L-shaped layout, includes three staircases, and contains 29 double-occupancy bedrooms in each floor (Figure 3). The building was constructed using precast concrete. The external walls have a U-value of 0.563 W/m²·K. The wall thickness is 27 cm including 4 cm of expanded polystyrene (EPS) insulation. Room windows are aluminum sliding windows measuring 2.35 m by 1.2 m. They are double-glazed, consisting of 6 mm-thick bronze-tinted glass divided by a 12 mm air gap, giving them a Solar Heat Gain Coefficient (SHGC) of 0.86 and a glazing U-value of 2.66 W/m²·K [6]. Windows have no shading devices, but they are uniformly distributed with one window allocated to each room. The building has a window-to-wall ratio of 9.9%, and a total façade area of 2032 m². All room surfaces were assumed to be adiabatic components except the exterior wall.

The simulated kinetic façade was inspired by origami, adopting a modular square shape, where each module measures 500 mm by 500 mm (Figure 4). This shape was chosen because it is easy to replicate, efficient in material use, and versatile enough to fit within different building types. Each module employs origami folding patterns, creating nine vertices that move in specific ways: the corners are fixed, while others move horizontally along the X axis, vertically along the Z axis, and the center vertex moves along the Y axis to create dynamic shading (Figure 4). Movements were restricted to 237.5 mm for the X and Z directions, and 219 mm for the Y direction, to ensure controlled and stable performance. Several building materials could be used in the construction of kinetic façades.

Table 3. Some commonly used materials in the kinetic façades [36,37,38].

Material	Density [Kg/m3]	Specific Heat [J/kg·K]	Conductivity [W/m·K]	Visible Light Transmittance [%]	Reflectance [%]	Emissivity
ACP	1230	1458	0.3	0	85	0.35
Polycarbonate	1210	1250	0.205	74	15	0.9
ACG	2500	792	1.05	40	10	0.84
PTFE	2200	970	0.29	45	60	0.875

shows some commonly used materials, including Aluminum Composite Panels (ACP), Aerogel-filled polycarbonate panels, Actuated Colored Glass (ACG), and Polytetrafluoroethylene (PTFE) panels [36,37,38]. ACP was assumed to be the primary construction material of the kinetic façade as it is already used as a façade cladding material of some students’ dormitory buildings on campus. ACP has a solar reflectance of 0.85, visible transmittance of 0.5, and specular reflectance of 0.5.

Figure 3. The site plan of the student housing zone [39], a typical floor plan and elevation, and the representative room used in the building simulation.

Figure 3. The site plan of the student housing zone [39], a typical floor plan and elevation, and the representative room used in the building simulation.

3.2. Simulation Variables and Cases

This study considered building orientation, kinetic façade cavity depth, and closure percentage as independent variables. It also considered Useful Daylight Illuminance, UDI, fabric gains, and cooling loads as dependent variables. Regarding the independent variables, three façade orientations were analyzed, i.e., south, east and west. The surrounding context, including trees and other surrounding buildings, was not considered. Cavity depth varies depending on design objective. For example, narrow cavities as low as 20 cm enhance stack effect and facilitate airflow to extract warmer air from occupied spaces [40,41]. In contrast, Deeper cavities, e.g., 1.2 m, provide access corridors and allow for shading devices installation [42]. This study considered five façade depths (ranging from 20 cm to 100 cm, in increments of 20 cm), and five façade closure percentages (ranging from 5% to 95%, in increments of 22.5%) as the key independent parameters.

As presented in

Table 4. A summary of the simulation cases considered in this study.

Variable	Façade Orientation
	South	East	West
No. of façade closure options	5	5	5
No. of cavity depth options	5	1	1
Resulting no. of simulation cases	25	5	5
Total			35

, this resulted in 25 operational scenarios for the examined façade with a southern orientation. To consider the effect of eastern and western façade orientations, an additional ten scenarios were analyzed, considering the above-mentioned five façade closure percentages and a fixed façade depth of 60 cm, which was sufficient to capture the trends of the thermal performance indicators as explained in the results section.

As for the dependent variables, UDI is typically defined as the percentage of occupied time (over a year) during which the indoor illuminance at a point lies between two set thresholds, commonly 100 lux and 3000 lux [43]. Values below 100 lux are considered under-lit, while values above 3000 lux are likely to cause glare. Thus, UDI assesses natural light availability, balancing visibility and comfort [44]. UDI was calculated using a grid of 108 measurement points with a daylight lower threshold of 125 lux, and an upper threshold of 2500 lux, providing greater protection against under-lit conditions and glare. A kinetic façade responding dynamically to solar exposure can reduce cooling loads by optimizing shading performance [45]. Solar exposure depends on building geometry, orientation, and urban context. In this regard, shading helps to reduce solar exposure and therefore minimize unwanted heat gains from direct sunlight and incident solar radiation on building surfaces. This significantly affects both energy use and thermal comfort conditions [46,47,48], as excessive solar exposure results in higher cooling loads and discomfort, particularly in hot climates.

3.3. Simulation Tools and Workflow

To evaluate the thermal performance of the examined kinetic façade, this study conducted a parametric simulation using Grasshopper for Rhinoceros (version 8), and the environmental plugins Ladybug and Honeybee (version 1.8.9). The simulation process began by developing a detailed 3D model of the building in Rhinoceros 3D. Grasshopper is a visual programming extension for Rhinoceros 3D. It enables users to create parametric designs without the need for coding or scripting. Additionally, it features an extensive library of add-ons that enhance its functionality [49]. Using Grasshopper, the study defined the kinetic façade geometry and control parameters, including the cavity depth between the inner and outer façade layers and the extent to which external shading panels were configured to open or close. Sliders and list components were used to create multiple façade scenarios, allowing rapid generation and testing of different design options. To account for local climate conditions, Ladybug was used to import and visualize weather data from the EnergyPlus Weather (EPW) file specific to Dhahran. This facilitated solar radiation analysis and UDI calculations. Simulations were conducted for each façade configuration to evaluate how the cavity depth and closure percentage influence daylight penetration into the rooms. Honeybee was employed for thermal analysis, including heat gains and cooling load calculations, using EnergyPlus modeling engine. The following usage conditions were considered: an occupancy intensity of 0.2 people/m², internal equipment heat gains of 3.5 W/m² [50], lighting heat gains of 4.5 W/m² [51] and a setpoint of 21 °C for heating and 24 °C for cooling. Data from both simulations were then analyzed and compared to identify patterns and trade-offs between daylight performance and solar exposure. Figure 5 summarizes the simulation process and variables.

4. Results and Discussion

4.1. Daylight Availability

Simulation results from the examined cases were analyzed, focusing on cavity depths from 20 cm to 100 cm and closure percentages from 5% to 95% for the southern orientation. UDI was selected to quantify daylight availability, as it accounts for both under- and over-illumination conditions, thereby providing insight into potential glare issues or insufficient lighting. Figure 6 shows the UDI results for the southern orientation of the examined façade configurations A general reduction in UDI values was observed following the application of the kinetic façade. It also shows how UDI is inversely proportional to the façade closure percentage, while being directly proportional to the cavity depth values. This relationship resulted in a consistent zigzag pattern, peaking at the highest cavity depth and the lowest façade closure percentage. The annual average of UDI recorded its highest value (29.9%) in the case of 5% closure percentage and 100 cm gap depth (case 5_100). UDI then gradually decreases as closure percentage increases until it reaches 5.2% in case 95_20. It can also be observed that within each closure percentage group, increasing cavity depth slightly improves UDI. This indicates that lowering the first parameters (façade closure percentage) and raising the second one (cavity depth) represent the optimal scenario for maximizing UDI while maintaining solar protection. Figure 6 also illustrates how daylight penetration varies in four selected cases that combine a combination of the maximum and minimum cavity depth, and the highest and lowest closure percentages of the kinetic façade. Daylight penetration patterns observed are consistent with the UDI data trends discussed above. While higher closure percentage results in lower daylight penetration, this could be improved by increasing cavity depth. This allows for multiple daylight reflections and therefore more daylight penetration into the space, as demonstrated when comparing cases 95_100 with cases 95_20.

Figure 7 illustrates the impact of the kinetic façade on UDI across various façade solar orientations, using the median value of cavity depth, i.e., 60 cm, for each closure percentage value (from 5% to 95%). A similar annual trend of UDI values was observed across the three solar orientations. However, a clear seasonal variation was noted when comparing summer averages (for June, July and August) to winter averages (for December, January and February). During summer, higher UDI values were observed in the eastern and western façades due to the lower solar angle characteristic of these orientations. Thus, the impact of façade closure in these two orientations was more significant compared to the southern one. UDI reduction in the eastern and western façades averaged about 35% compared to 26% in the southern façade. In winter, however, the southern orientation outperformed other orientations due to the lower solar angle in winter. This resulted in an increase in UDI value by about 13%. At the highest façade closure percentage (95%), all orientations nearly converged, indicating minimal influence of solar orientation under these conditions.

4.2. Cooling Load Analysis

One of the most important advantages of using kinetic façades in hot climates is their ability to provide shading. This effectively reduces heat gains through both glazing and opaque elements of building envelope, which in turn reduces cooling loads. Figure 8 shows the impact of kinetic façade on the annual cooling load considering cavity depths from 20 cm to 100 cm and closure percentages from 5% to 95% in the southern orientation. In Dhahran, cooling is required for most of the year due to persistently high outdoor temperatures. In winter, cooling systems are typically switched off, and heating is rarely required, usually only for a few weeks. Therefore, priority should be given to reducing cooling load throughout the year. Overall, the kinetic façade consistently achieves a reduction in cooling load compared to the base case. However, the extent of reduction varies depending on the combination of closure percentage and cavity depth. The lowest cooling loads are observed at higher closure percentages (72.5% and 95%) combined with smaller cavities, where solar penetration is minimized and cooling load demand drops below 6000 kWh. In contrast, deeper cavity depths and lower closure percentages yield less significant reductions for the investigated south-facing façades.

Figure 9 compares the impact of the kinetic façade on the annual heat gains and cooling loads across various façade orientations, using a median cavity depth of 60 cm, for each closure percentage value (from 5% to 95%). Heat gains through glazing and external wall consistently decrease at higher façade closure ratios for all orientations, reflecting the façade’s effectiveness in reducing heat gains. The western façade shows the highest annual heat gains in the base case, which gradually decrease until a reduction of 45% is achieved at 95% closure. The southern and eastern façades show lower initial values and follow similar descending trends achieving reductions of approximately 36% and 40%, respectively, at 95% closure. This indicates that the kinetic façade can efficiently reduce solar exposure, especially on the western orientation, which is exposed to solar radiation at lower angles in the afternoon.

The observed reduction in heat gains throughout the year has a direct impact on lowering the cooling load. Figure 9 illustrates the influence of different kinetic façade closure percentages on the total annual cooling load for the examined solar orientations. Across all orientations, increasing the façade closure percentage leads to a reduction in cooling load, demonstrating the façade’s effectiveness in mitigating heat gain through building envelop as previously discussed. This follows the same trend identified in the heat gains analysis. Cooling load reduction was more significant in the western façade, where reductions of 26% was observed in comparison to the base case at 95% closure.

Figure 10 illustrates the annual reduction in UDI and cooling load compared to the base case, considering various façade closure percentages and solar orientations. Overall, higher closure percentages result in greater reductions in both UDI and cooling load, although the extent varies across the different orientations. The conflict between the two objectives, minimizing UDI reduction and maximizing cooling load reduction, can be clearly observed, as achieving one objective requires some compromise in the other. The optimal scenario in this regard depends on specific design priorities. If equal importance is assumed for both objectives, the required trade-off is strongly influenced by façade orientation. In this case, the mid-range façade closure percentage provided a balanced performance across the three examined orientations. However, the southern façade performs slightly more efficiently. For example, at 50% closure, the cooling load was reduced by about 16% compared to the base case, with a UDI reduction of 44%. This outperforms the eastern and western façades, which achieved lower cooling reductions of about 11% and showed a similar UDI compromise. This indicates that the eastern and western orientation sacrifice daylight more heavily than they save cooling energy in this case. Thus, a dynamic approach in these two orientations is recommended, where closure ratio could be increased in the morning on the east and in the afternoon on the west, while relaxing closure at other times to preserve daylight. This ensures a better balance between cooling efficiency and daylight availability.

5. Conclusions

Energy retrofitting is particularly important for buildings that were constructed before the implementation of modern energy standards. This approach mainly aims to reduce energy consumption and associated greenhouse gas emissions while improving occupants’ comfort and indoor environmental quality. It can be achieved through several measures, such as upgrading the building envelope. In particular, facade upgrades are considered one of the most effective retrofit strategies for reducing building energy use—kinetic façades are an attractive solution in this regard due to their environmental and architectural advantages. They can be controlled to respond to different seasonal needs including shading, making them an effective retrofit strategy that enables dynamic movement across the façade surface rather than maintaining a fixed and static building form.

This study examined the effect of integrating an origami-based kinetic façade into a student dormitory building in Dhahran, Saudi Arabia, focusing on daylighting levels and cooling demand. A parametric numerical simulation was conducted to analyze façade closure percentages, ranging from 5% to 95%, and cavity depth, ranging from 20 cm to 100 cm. Selected cases were also simulated to assess the impact of façade solar orientation. The simulation workflow used Rhinoceros 3D, Grasshopper, and the environmental plugins Ladybug and Honeybee. The use of parametric simulation provided a robust framework for performance-based building design and retrofit, enabling a clear understanding of how kinetic façades can dynamically respond to changing environmental conditions and enhance both energy efficiency and occupant comfort. In general, findings showed that several key performance parameters should be considered when evaluating kinetic facades or other facade interventions. Among these, daylighting quality and solar exposure control are essential, as they directly influence both energy efficiency and occupant comfort. It is important to note that daylighting and solar exposure control are interrelated parameters. A façade intervention that blocks sunlight will reduce glare and heat gains, but if not designed carefully it might also dim the daylight to under-lit levels. The advantage of kinetic facades is their ability to balance these two factors dynamically, where the use of metrics such as UDI and heat gains through building envelop is needed. By monitoring these metrics, designers can adjust variables such as the size, spacing, and timing of facade panel movements to find an optimal solution.

Analyzing the resulting UDI, heat gains and cooling loads showed that the folding patterns of the façade significantly affected the environmental performance of the building and improved its adaptability to the seasonal climate changes. Results from the 35 simulation cases demonstrated that both cavity depth and closure percentage of the kinetic façade play crucial roles in balancing daylight availability and solar protection. UDI analysis showed a consistent decline in daylight performance as closure percentage increased, while cavity depth had a positive but limited influence. Cooling load analysis confirmed that the kinetic façade was highly effective in reducing heat gains, with more substantial reductions occurring at higher closure percentages. However, these benefits came with considerable daylight losses, as higher closure ratios led to greater reductions in daylight availability. In this case, the mid-range façade closure percentage provided a balanced performance across the three examined orientations. However, the southern façade performs slightly more efficiently. For example, at 50% closure, the cooling load was reduced by about 16% compared to the base case, with a UDI reduction of 44%. This outperforms the eastern and western façades, which achieved lower cooling reductions of about 11% and showed a similar UDI compromise. These findings suggest that a dynamic façade operation is essential, where higher closure ratios could be applied during peak solar hours on the east in the morning and the west in the afternoon to maximize cooling savings, while moderate closure ratios can be maintained on the south to preserve daylight. This adaptive strategy ensures a more effective balance between solar protection and daylight availability.

Some limitations of this study include the specific climatic conditions and geometrical parameters that were considered, which may restrict the generalizability of the results. The choice of kinetic façade material also presents a limitation, as alternative materials with varying thermal and optical properties could significantly influence façade performance. Moreover, the building’s immediate context, such as surrounding trees, adjacent structures, and topography, was not considered in the simulation process. Future research should extend these findings through glare analysis, airflow simulation within the façade cavity, and control-based dynamic simulations to reflect real operational behavior. Incorporating real-time environmental data and advanced smart materials, like phase-change materials or shape-memory alloys, is also recommended to further enhance façade adaptability and performance.