Perspective Chapter: From Data to Design – Leveraging Façade Sensors for Intelligent Architecture

Abstract

This chapter explores the fascinating domain of leveraging façade sensors for intelligent architecture, focusing on the seamless transition from data to design. This study will delve into the integration of advanced sensor technologies within building façades to collect valuable data that inform the architectural design process. This chapter investigates how these sensors provide real-time information on various aspects, such as environmental conditions, occupancy and energy usage, enabling architects to design responsive, sustainable and occupant-centric buildings. Architects can improve building performance, optimise user experience and shape the future of intelligent architecture by harnessing the capabilities of façade sensors.

1. Introduction

The built environment has been significantly affected by the incorporation of technology into architecture. Developments in sensor technologies have paved the way for intelligent architecture. The design, construction and operation of buildings can be completely transformed by the use of sensors [1]. By integrating these sensors, architects can gain real-time insights into a building’s surroundings, empowering them to design façades that respond intelligently to climate, natural ventilation, solar heat gain and daylighting. As a result, buildings have become more sustainable and energy efficient, decreasing their reliance on artificial lighting, heating and ventilation systems [2]. To design spaces that satisfy the needs of their occupants, architects can use façade sensors to monitor occupancy patterns. These data assist architects in designing spaces that meet their requirements, such as optimising low-occupancy spaces to save energy while still providing sufficient social and seating areas for high occupancy. By identifying unauthorised access or unusual movement patterns, occupancy sensor data can also help improve building security [3].

Façade sensors also play a significant role in monitoring and improving energy utilisation in buildings by coordinating energy use sensors into the façade, and architects can monitor and analyse the use of power, water and different utilities, empowering them to make informed design decisions that focus on energy efficiency [4]. These data can be used as a guide for design interventions such as better insulation, appliances that use less energy and renewable energy systems. It can also be used to show building users’ real-time energy consumption data to encourage environmentally friendly behaviour. The capability of façade sensors is not only to collect data but also to translate these data into practical recommendations. Architects can now use real-time data to make informed design decisions thanks to advancements in data analytics and visualisation methods. This iterative design process permits architects to enhance their designs for numerous parameters simultaneously, guaranteeing a balance between aesthetic, function and performance considerations.

The integration of façade sensors into intelligent architecture has far-reaching implications beyond the planning stage of a project. By enhancing the user experience and contributing to a more sustainable and occupant-centric built environment, buildings that use façade sensors can shape the future of intelligent architecture. Façade sensors help reduce a building’s impact on the environment while also improving user health and safety, productivity and satisfaction. For example, buildings can create spaces that adjust to individual inclinations, advancing occupant comfort and satisfaction by tailoring the indoor climate based on real-time data. The seamless change from data to design is reforming the field of architecture by providing architects with a deeper understanding of different aspects of design, such as site conditions, environmental factors, building performance and user behaviour. Because of this change in practise, architects are now able to make design decisions based on evidence, which enables them to come up with solutions that are more responsive and appropriate to the context. The capacity to enhance building performance is one of the primary advantages of the seamless transition from data to design. The seamless integration of data into the design process also enables architects to evaluate design alternatives more effectively. Before construction begins, data-driven simulations and modelling can help architects evaluate the performance of various design options, thereby minimising errors and avoiding costly modifications during construction. In addition, the effortless transition from data to design encourages interdisciplinarity and collaboration. For holistic and integrated design solutions, architects can work with builders, environmental consultants and other relevant professionals to collect and analyse relevant data [5].

However, there are obstacles in achieving a seamless transition from data to design. One of the major questions is the shear volume and intricacy of the information accessible. Architects must be equipped with the necessary skills and tools to collect, analyse and interpret data effectively. Realising the potential of data-driven design requires embracing parametric modelling, data visualisation, and computational design methods. The incorporation of data into the design process itself is yet another disadvantage. To achieve a balance between artistic vision and empirical evidence, architects must adopt a mindset that views data as an essential resource [6]. This chapter explores the seamless application of façade sensors in intelligent architecture. This study focuses on the collection and analysis of valuable data as it explores the incorporation of cutting-edge sensor technologies into building façades. This chapter features the pragmatic uses of façade sensors, such as monitoring climate data, predicting user behaviour and optimising energy consumption. Additionally, it emphasises the advantages of user-centred design, flexible spaces, responsive design and the incorporation of façade sensors into intelligent architecture. This chapter accentuates the enhancement of building performance through sensor-driven tasks, propelling sustainability by designing green buildings and the inventive capability of occupant-centric buildings, as well as enhancing health and safety.

2. Overview of façade sensors

In architecture, façade sensors play a key role in the development of smart and sustainable buildings. These sensors are integrated into the exterior surfaces of a building’s façade to monitor and respond to various environmental factors, occupancy and energy usage. They offer rich data and insights that architects, builders and building operators can use to optimise the building’s performance, comfort and energy efficiency.

2.1 Definition and type of façade sensors

2.1.1 Definition façade sensors

Façade sensors, also referred to as building envelope sensors or climate sensors, are instruments strategically positioned on the exterior surface of a building’s façade to measure and monitor several environmental parameters [7]. These parameters include temperature, humidity, wind speed, solar radiation, air quality and noise levels.

Façade sensors are specialised devices placed on the outer surface of buildings to retrieve data on environmental conditions such as temperature, humidity, light levels and wind speed, which are crucial for improving energy consumption and comfort [8].

Façade sensors entail various sensing technologies installed in the building envelope. These sensors enable real-time monitoring and assessment of external factors, enabling responsive and energy-efficient building operations [9].

Façade sensors are tools incorporated on the external faces of buildings to detect environmental parameters. They offer data that supports smart building management systems, allowing for dynamic modifications in lighting, heating and ventilation to conserve energy and improve comfort [10].

Façade sensors include multiple sensors and data gathering instruments integrated into a building’s façade. These devices continuously monitor parameters such as solar radiation, air quality and temperature. The retrieved data are used to improve energy utilisation and form sustainable and responsive building environments [11].

2.1.2 Types of façade sensors

2.1.2.1 Temperature sensors

Temperature sensors are important for contemporary architecture because they provide valuable data that helps architects and building operators create efficient, comfortable and sustainable environments. These sensors are integral components of smart buildings, enabling real-time monitoring and control of indoor and outdoor temperatures. Their application in architecture spans several phases, from initial design to post-occupancy evaluation. In the early stages of architectural design, temperature sensors facilitate building energy simulations and modelling. They assist architects in assessing how sunlight and outdoor temperature variations affect the building’s thermal comfort. This insight enables the design of passive heating and cooling systems, such as building orientation, shading and natural ventilation, to reduce the dependence on energy-consuming heating, ventilation and air conditioning (HVAC) systems. After a building is completed, temperature sensors are installed indoors to sustain thermal comfort for the occupants. These sensors monitor indoor temperatures, ensuring that they remain within a designed range for different locations of the building. Architects can create responsive and zoned climate control, allowing personalised comfort for occupants while optimising energy consumption by linking temperature data to HVAC systems [12].

Temperature sensors provide real-time data that can be incorporated into building management systems. This data allow for the dynamic regulation of heating, cooling and ventilation systems based on existing situations. For example, if a class room experiences a sudden increase in occupancy, temperature sensors can signal the HVAC system to adapt and sustain an optimised environment. When combined with occupancy sensors, temperature sensors facilitate smart climate control systems that adjust to the number of people in an area. Unused spaces can be conditioned to a reduced level, reducing energy use while ensuring comfort when occupants are around. Architects are gradually integrating temperature sensors into adaptive façades and building envelopes. These sensors deliver data to manage dynamic shading devices, louvres and phase-changing materials that respond to outdoor weather conditions. This approach improves energy efficiency and reduces the building’s environmental impact. When the building is in use, temperature sensors continue to contribute to its performance evaluation. Architects can identify areas for improvement and fine-tune the building’s systems to achieve superior performance and comfort by evaluating temperature data with a combination of energy consumption data. In larger construction projects, temperature sensors play a role in smart grid integration. Buildings equipped with temperature sensors can participate in demand response programmes, regulating their energy utilisation during peak periods, thus enabling grid stability [13].

2.1.2.2 Humidity sensors

Humidity sensors gauge the amount of moisture in the air, providing data that assists architects and facility managers in optimising HVAC systems, preventing moisture-related issues and improving the general health and safety of occupants. Humidity sensors are crucial for sustaining optimal indoor air quality and comfort. Architects can guarantee that indoor areas remain within the planned relative humidity level (typically 30–60%) [12]. Appropriate humidity regulation hinders the growth of mould and mildew, minimises the risk of respiratory issues, and promotes a better indoor environment by continuously controlling humidity levels. In areas with fluctuating weather, humidity sensors help avoid condensation problems on windows and walls. By providing real-time humidity data, these sensors enable architects to design proper insulation ventilation systems. Humidity sensors are influential in improving HVAC systems, mainly in humid environments. When incorporated with building automation systems, these sensors allow smart control of humidification and dehumidification processes and reduce energy waste [14].

Humidity levels can, to a large extent influence, the durability of building materials such as timber, steel and paint. Architects can prolong the service life of these materials, thereby reducing maintenance budgets and preserving the building’s aesthetics by maintaining suitable humidity levels. Humidity sensors are essential in critical spaces of the building, such as bathrooms, kitchens and basements, where moisture levels tend to vary. Early identification of high humidity in these areas can enable proper ventilation and humidity control measures, mitigating potential dampness and growth of biological deterioration agents. In construction projects involving indoor agriculture or greenhouses, humidity sensors play a critical role in improving the growth environment for plants [12]. These sensors help maintain the appropriate level of humidity to support plant growth and prevent pest diseases. Humidity sensors allow for data-driven design and post-occupancy evaluations. Building designers can identify areas for improvement, optimise system performance and ensure that the building meets its performance objectives by analysing humidity data with other environmental parameters.

2.1.2.3 Light sensors in the architecture

Light sensors, also referred to as photodetectors, are instrumental devices in modern architecture, that enable accurate monitoring of artificial lighting systems and optimise energy efficiency. These sensors create green and human-centric built environments, by providing real-time data on natural and artificial light conditions. Light sensors are an integral element of energy-efficient lighting systems in architecture [15]. By measuring the intensity of natural light in a space, light sensors enable the automatic regulation of artificial lighting [16]. When daylight levels are satisfactory, artificial lighting dims or turns off, thereby minimising electricity usage immensely. This dynamic lighting control system not only lowers energy consumption but also reduces greenhouse gas emissions. Integrating light sensors into building design allows effective daylight harvesting, an approach that uses natural light as the main source of lighting. Light sensors can detect the varying daylight levels and match with lighting regulators to sustain a continuous lighting condition. Buildings can attain higher energy efficiency and Leadership in Energy and Environmental Design (LEED) certification by reducing the use of natural light [17]. Light sensors contribute to improving occupant health and safety by considering the human circadian rhythm. These sensors can control artificial lighting intensity and colour temperature during the day to align with sunlight’s varying qualities. Buildings can positively impact occupants’ sleep behaviours, productivity, and well-being by promoting a circadian lighting environment [18].

Light sensors are often integrated with occupancy sensors to produce occupant-responsive lighting systems. When occupants are identified in a specific location, the light sensors evaluate the available sunlight and alter the artificial lighting levels. Thus, energy is preserved by providing lighting only when needed, thereby minimising running costs [19]. Combining light sensors with adaptive façades and building envelopes enhances the sustainability of architecture. These sensors detect incoming artificial lighting and alter shading devices, glass tinting or dynamic elements on the façade to improve sunlight diffusion and thermal comfort [20]. The adaptive nature of the façades reduces the building’s energy demands, forming a more environmentally friendly design. Light sensors allow architects to assess the effectiveness of lighting design approaches. Architects can fine-tune their design and improve the building’s performance by collecting data on light levels, usage behaviours and occupant feedback [21, 22].

2.1.2.4 Air quality sensors

Air quality sensors are indispensable devices in smart architecture, allowing precise monitoring and control of indoor air contaminants. These sensors are crucial for creating healthy and comfortable indoor environments while contributing to energy efficiency and sustainability. Air quality sensors allow architects to consistently control indoor air pollutants, such as volatile organic compounds (VOCs), particulate matter, carbon dioxide (CO₂) and formaldehyde [23]. These sensors allow timely responses to variations in contaminant levels, ensuring that occupants breathe clean and safe air by offering real-time data on air quality. Air quality sensors are combined with ventilation systems to facilitate demand-based ventilation. When pollutant levels are above satisfactory thresholds, the sensors activate increased ventilation flow rates to eliminate toxins and improve indoor air quality [24]. This adaptive ventilation strategy not only improves occupant comfort but also reduces electricity consumption by avoiding unnecessary ventilation. Maintaining good indoor air quality is critical for the welfare and productivity of building occupants. Air quality sensors facilitate the identification of harmful contaminants that can cause respiratory diseases. Architects can contribute to a healthier and more productive indoor environment by proactively managing indoor air quality.

2.1.2.5 Solar radiation sensors

Solar radiation sensors, also referred to as solar pyranometers, are vital tools in modern architecture for evaluating solar energy availability and improving sustainable building design. These sensors allow architects to harness sunlight to enhance the energy efficiency of buildings. Solar radiation sensors play a crucial role in Site analysis during the early stages of architectural design [25]. By measuring solar irradiance, architects can evaluate solar access and detect areas with improved sunlight. These data help in determining the orientation of the building to reduce natural light consumption and eliminate the need for artificial lighting during the day. Architects can design passive solar systems that use solar energy for heating and lighting. By strategically placing windows, roof lights and shading instruments based on solar radiation data, buildings can achieve improved thermal comfort and energy efficiency [26]. Passive solar design reduces dependence on artificial heating and cooling systems, leading to energy savings and reducing carbon footprint.

For buildings that integrate photovoltaic cells (PV) systems, solar radiation sensors are essential for system improvement. By controlling solar irradiance levels, architects can determine the most suitable positions and angles for PV panels to increase energy generation. This improvement ensures that PV systems produce the highest electricity output from existing sunlight. Solar radiation sensors are incorporated into building energy simulation tools to model solar gains and evaluate building performance. Using solar radiation data, architects can simulate a building’s energy performance, forecast cooling and heating demands, and assess passive solar design approaches [27]. This assessment helps in making informed design decisions to design energy-saving buildings. Solar radiation sensors contribute to dynamic façade design. These sensors can identify incoming solar radiation and activate responsive shading systems. The dynamic façade adapts to varying solar conditions, maintaining a comfortable indoor environment and lowering cooling needs.

2.1.2.6 Occupancy sensors

Occupancy sensors, also referred to as motion detectors, identify the movement of occupants in an area to allow accurate monitoring of lighting, heating, ventilation and air conditioning (HVAC) systems. Occupancy sensors are valuable in sustainable lighting control in architecture because they identifying the occupants in a space and activate automatic on/off of lighting systems [28]. Consequently, electricity usage is reduced by eliminating the need for illumination in vacant spaces. Combining occupancy sensors with HVAC systems allows for adaptive climate control in buildings. When people are identified in an area, the sensors can alter the heating or cooling levels to maintain thermal comfort. In vacant spaces, the ventilation system can work at lower levels to save energy. Occupancy sensors enable personalised user experience in building spaces [29]. The sensors can adapt lighting, ventilation and other environmental parameters to satisfy user needs, which improves occupant indoor comfort.

These sensors are usually integrated with light sensors in a daylight harvesting system to regulate artificial lighting settings based on the available sunlight which will enable energy saving by lowering artificial lighting when sunlight is adequate. They also help in enhancing building security and safety. In vacant spaces, sensors can initiate lighting or security systems. When integrated with a building automation system, data from occupancy sensors aid smart and energy-saving building operation, which contributes to a green built environment. Architects use occupancy sensor data to inform data-based design, improve space allocation, identify opportunities for energy saving and comfort optimisation by analysing occupant behaviours.

2.1.2.7 Structural health monitoring sensors

Structural health monitoring (SHM) sensors allow consistent monitoring and surveillance of buildings. These ensure the safety, reliability and maintenance of the building. They facilitate real-time and consistent monitoring of the structural integrity of buildings. They are strategically installed in structural elements, such as slabs, beams, columns and foundations, to determine shear stress, deflection, vibration and uneven settlement. SHM sensors help in the timely identification of structural decay. Any changes in the behaviour of a building, such as differential settlement or sudden shock, can indicate potential issues; they provide a warning signal of potential structural problems for preventive maintenance [30]. With SHM sensors, architects can develop performance-driven design and appraisal methodologies. Instead of relying on design codes, architects can use real-time data from sensors to validate design assumptions and improve structural stability. This method results in cost-effective designs.

The application of micro-electro-mechanical systems (MEMS) sensors in the diagnosis of seismic capacity for historic structural glass systems indicates a new advancement in structural engineering. These sensors offer real-time monitoring capabilities, enabling continuous data capture of structural vibrations and responses. This information supports structural engineers in understanding the dynamic behaviour of these glass structures, mainly under seismic loads [31]. MEMS sensors, characterised by their high precision and sensitivity, can detect subtle structural movements and potential problems. In addition, MEMS sensors are important for evaluating the mechanical performance of glass façades subjected to seismic loads. These sensors monitor vibrations, strain and deformation in real time, providing invaluable data for structural engineers to analyse structural integrity during earthquakes. By allowing detailed data capture and assessment, MEMS sensors support informed decision-making for maintenance, improving the safety and resilience of glass façades in seismic-prone regions [32].

2.2 Integration of advanced sensor technologies into building façades

In the quest for smart architecture, the incorporation of smart sensor technologies into building façades has emerged as a promising strategy. These smart sensor technologies, ranging from occupancy sensors to light detectors, are critical to improving user experience, improving building performance and reducing carbon footprints. Photodetectors are important when incorporated into building façades for daylight harvesting. They gauge the quantity of sunlight in buildings and regulate artificial lighting settings. Through this adaptive lighting control, electricity usage in buildings can be reduced by using available natural sunlight. Sunlight harvesting not only conserves energy but also contributes to occupant health by providing natural lighting environment. Incorporating humidity detectors in building façades enables accurate climate control. These sensors monitor indoor humidity, allowing HVAC systems to regulate heating and ventilation by optimising thermal comfort in real time, which facilitates energy savings without detriment to user satisfaction [33]. Moreover, they help prevent condensation, ensuring a healthier indoor environment. They are also instrumental in creating energy-efficient spaces within building façades. These sensors detect the presence or absence of occupants in rooms and trigger the lighting and HVAC systems accordingly. By turning off lights and reducing heating or cooling in unoccupied areas, buildings can achieve substantial energy savings.

Solar radiation sensors, also called pyranometers, are important the design of green building façades. They gauge solar irradiance and support architects in determining building orientation and shading design [34]. Buildings can reduce dependence on mechanical lighting and ventilation systems, leading to less energy utilisation and environmental impact by leveraging sunlight. Incorporating air quality detectors in building façades aids in the realisation of a healthy indoor environment. These sensors detect volatile organic compounds (VOCs) and carbon dioxide (CO₂), providing sensible ventilation control [12]. Maintaining acceptable indoor air quality improves occupants’ mental health and productivity, making it a critical consideration in contemporary architecture. Integrating proximity sensors in building façades allows touchless interaction in building areas. They sense hand gestures and enable touchless control of doors, elevators and windows. Touchless control encourages hygiene, reduces the spread of diseases and addresses post-COVID design considerations. The incorporation of SHM detectors in building façades, guarantees the safety and longevity of buildings by monitoring stresses and vibrations to assess structural integrity. The timely identification of structural problems through SHM detectors allows for preventive maintenance and disaster management [31].

2.3 Collection and analysis of sensor data

In the field of smart architecture, the collection and analysis of sensor data in building façades have become important for creating energy-saving, user-centric and resilient buildings. Smart sensor technologies installed in building façades enable real-time data gathering, giving architects valuable insight into numerous areas of building performance. Environmental sensor networks are embedded in building façades to offer real-time surveillance of environmental parameters [33]. They monitor temperature, humidity, air quality and solar radiation, assisting architects in understanding the building’s response to environmental conditions. The data captured helps in enhancing indoor climate control systems, optimising occupant comfort and saving energy. Light sensors, installed in building façades, allow daylight harvesting through the measurement of sunlight intensities [35]. This data-driven method enables for adaptive lighting adjustment, where mechanical lighting is controlled based on available sunlight. Sunlight harvesting also improves the health of the occupants by creating a dynamic lighting environment.

Occupancy sensors, a vital component of building façades, detect the presence or absence of occupants in various spaces [3]. The data captured by these detectors enable energy-efficient building operations by activating lighting and climate control systems based on real-time occupancy behaviours. This automated system enhances resource use and agrees with green building agenda. SHM sensors are embedded in building façades to monitor their structural integrity [32]. Data from SHM detectors enable architects to perform early maintenance to ensure the safety and resilience of the building. The valuable data retrieved from several detectors in building façades allow designers to embrace data-informed design solutions and decision-making [36]. Analysing the retrieved data enables for evidence-based design adjustments. Data-driven decisions lead to better space allocation, improved energy efficiency and improved user satisfaction. Incorporating data retrieved from building façade detectors into smart building systems improves building performance. Data integration enables dynamic building operations, where different systems work together to enhance energy utilisation, user experience and sustainability. Smart building sensors leverage big data to create an adaptive and user-centric building environment.

3. Real-time information on architectural design

3.1 Environmental condition sensors

In the search for sustainable and climate-responsive architecture, monitoring and analysing climate data play a significant role in shaping state-of-the-art façade. Façades, as the outer skin of buildings, act as the interface between the outdoor and indoor environments. Architects can design façades that adapt to dynamic weather by integrating climate data into the design processes. Monitoring climate data offers a better understanding of local weather patterns, temperature and radiation levels. This information aids architects in choosing suitable façade materials, shapes and shading to enhance building performance. Climate data-driven design approaches enable the development of passive façades that respond to environmental conditions, thereby reducing the building’s reliance on artificial heating, ventilation and lighting. Analysing climate data is important for optimising thermal comfort in façade design. Understanding temperature variations and wind patterns helps architects implement passive design measures that control internal temperature [37]. Double-skin façades, thermal mass incorporation and natural ventilation can drastically impact the internal thermal environment and safeguard user health. Climate data inform sunlight harvesting agendas and solar gain control in façade design. Architects can determine optimum glazing ratios, orientation and shading to reduce sunlight while minimising undesirable solar heat gain by analysing solar radiation data. This approach optimises visual comfort and supports circadian rhythms. Integrating climate data into façade design allows climate adaptation measures. Architects can design façades that resist heavy rains, lateral forces and heat by understanding the climate conditions [38]. Climate adaptive façades contribute to the long-term durability and functionality of buildings in dynamic climates.

Monitoring and analysing climate data are key in considering the embodied energy of façade materials. Studying the environmental impacts of material selection aids architects in choosing green materials [39]. Climate-conscious material selection helps reduce the greenhouse gases in buildings. Climate data plays a critical role in forecasting and measuring building energy performance. Energy simulation platforms, integrated with climate data, allow architects to assess the energy efficiency of different façade design strategies [40]. This analysis allows for iterative design processes, leading to energy-efficient façades that align with sustainable goals. Monitoring and analysis of climate data after construction aid data-driven façade improvement. User experience helps architects evaluate the actual performance of the façade design. Real-world data aids in detecting spaces for optimising design, ensuring that the façade performs as intended during its life cycle.

Incorporating weather patterns into façade design decisions has emerged as a transformative approach. Architects can design façades that adjust to change environmental conditions, and enhance occupant comfort by harnessing. Integrating weather patterns into façade design includes using climate data to inform design strategies. By evaluating previous weather data and climate forecasts, architects can obtain insights into temperature variation, radiation level and wind direction [41]. This data-driven methodology allows the design of façades that respond to environmental conditions, facilitating passive design that reduces dependence on artificial heating, ventilation and lighting. Integration of weather patterns into façade design improves thermal comfort for building occupants. Understanding temperature variations and wind patterns allows architects to optimise the façade’s thermal performance [37]. Features such as advanced insulation, glazing with appropriate solar heat gain coefficients, and passive solar design principles contribute to a comfortable indoor environment, thereby reducing energy consumption and improving occupant well-being.

Climate data empower architects to harness sunlight and control solar gain. By analysing solar radiation data, architects can improve façade fenestration, shading systems and light redirection elements. Amplifying sunlight while minimising heat gain reduces the building’s energy load and creates visually comfortable and healthy spaces. Weather-based façade design contributes to climate adaptation. Integrating weather patterns into façade design aligns with sustainability goals. Climate-driven design includes selecting materials with less environmental impact that lower energy consumption [38]. Such considerations foster environmentally friendly architecture and reduce the building carbon footprint. Monitoring and analysing climate data enable energy improvement in façade design. Building performance simulations, combined with climate data, allow architects to assess the energy efficiency of different façade [4]. Monitoring weather patterns after construction aids in data-driven façade improvement. Real-world performance feedback informs architects of the façade’s actual response to the climate. This data-driven approach allows for fine-tuning, ensuring that the façade remains climate-responsive throughout its lifespan.

3.2 Occupancy sensors

Architects are increasingly integrating technology to track user behaviour in buildings. This method seeks to enhance creating user-centric buildings. Designers can understand how occupants use the building façade, enabling for bespoke design that responds to change preferences by leveraging data analytics. Monitoring user behaviour enables architects to understand how occupants interact with the façade. Designers can identify patterns of user movement by analysing data from motion sensors and occupancy detectors [42]. This data-driven strategy allows architects to design façades that cater to specific user preferences. Architects can anticipate user preferences and adjust the façade’s features. For instance, the façade could automatically adjust shading, ventilation or lighting based on user comfort needs, resulting in a user-friendly building. Tracking occupant behaviour contributes to optimising thermal comfort. Architects can enhance façade design to provide adequate sunlight and regulate the indoor environment by tracking occupant movements. Real-time data feedback informs design decisions, leading to efficient sunlight use and reducing the need for artificial lighting.

Predicting occupant behaviour promotes architectural innovation. Continuous data gathering and analysis enable architects to assess the efficiency of design [43]. This approach leads to innovative façade designs that evolve with occupant preferences. Design decisions are driven by the goal of designing buildings that ensure the health and safety of occupants. This approach promotes a stronger link between the building and its users, resulting in more functional spaces. Data-driven insights into occupant behaviour support building maintenance. Facility managers can enhance space allocation and manage resources by understanding user preferences.

Designing façades based on user behaviour includes the incorporation of sensors in buildings. Motion detectors and thermal cameras are used to gather data on occupant’s behaviour [28]. These sensors offer real-time and past data, which architects can leverage to enhance façade design for occupant comfort. Architects can design façades that respond in real-time to the changing preferences of building users by analysing user activity data. Designing façades based on occupancy behaviour improves user experience. Understanding how occupants use spaces aids architects in designing intuitive layouts [44]. Architects can fine-tune building systems to align with actual needs by monitoring occupant movement. This approach supports environmentally responsible design. Data on occupancy patterns aid facility management. Facility managers can use the data to improve HVAC systems, and manage space allocation [45].

3.3 Energy usage sensors

Monitoring energy usage in façade design includes the incorporation of sensor technology. Smart metres, occupancy sensors and environmental detectors aid real-time data collection on energy usage, indoor environments and lighting conditions [28]. This information informs architects about building performance. They are vital in enhancing energy savings through façade design. Architects can detect energy-intensive spaces and energy-saving opportunities by analysing sensor data. This approach facilitates evidence-based design strategies, resulting in façades that minimise operational costs. Façade design can integrate passive strategies such as thermal mass, shading devices and natural ventilation to regulate indoor airflow and optimise energy consumption. Monitoring energy usage through façade design aligns with green building practises. Implementing energy-efficient façades is essential for achieving global sustainability goals [44]. Façade design can incorporate passive strategies to enhance sustainability. Passive design harnesses natural resources, enhancing daylight and thermal conditions to reduce the need for HVAC.

Façade design can incorporate energy-saving glazing. By using high-performance glazing with low U-values and effective insulation materials, architects can greatly reduce energy loss [46]. Improved glazing contributes to better thermal comfort, thus creating a sustainable building. Dynamic façades offer an innovative approach to energy saving. By incorporating sensors, façades can adjust to varying environmental conditions and user preferences. Switchable glazing and adaptive insulation optimise façade’s performance and occupant comfort. Architects can maximise sunlight penetration into the building, reducing the reliance on artificial lighting by using light-redirecting devices. Incorporating sustainable materials into façade design is key to sustainability. Architects can assess the environmental impacts of façade materials and construction methods. Net-zero energy façades are the pinnacle of sustainable building design. These façades produce as much energy as they use, often through integrated renewable energy sources. Net-zero energy façades demonstrate a commitment to environmental responsibility and mitigating climate change. Climate-responsive façade design tailors buildings to local climatic conditions. Using weather patterns, architects can design façades that adapt to varying temperatures, sun exposure and wind [28].

4. Leveraging façade sensors for a responsive design

4.1 Designing adaptable spaces

4.1.1 Dynamic façades that respond to environmental conditions

Dynamic façades in architecture characterise an important development in the area, where building externals are designed to react smartly to dynamic weather conditions. These façades are designed to communicate with environmental factors such as sunlight, temperature and wind, demonstrating a state-of-the-art combination of technology, sustainability and aesthetics [4]. This architectural approach supports diverse purposes, ranging from improving energy efficiency to creating appealing visual experiences. The core idea behind dynamic façades is to design building envelopes that are capable of adapting themselves to enhance the indoor environment. Such flexibility can greatly influence a building’s energy utilisation and thermal comfort, aligning with the overall objectives of sustainable architecture. The components used in dynamic façades differ, integrating several technologies and design methods. One strategy includes the application of photochromic and thermochromic materials in façade mechanisms. These materials respond to variations in luminous intensity and temperature, triggering the façade’s appearance to change. Another method integrates kinetic components, such as movable louvres, panels and shading devices. These components can be manually regulated or automated to control parameters such as light infiltration, ventilation and sensible heat gain.

Researchers have shown a growing attention to dynamic façades. Bedon et al. [36] discusses the structural aspects and performance assessment of adaptive façades in modern buildings. Adaptive façades are designed to respond to changing conditions and improve the overall building performance. They highlight the need for experimental methods and regulations to evaluate the structural safety, durability and fire safety of these innovative façade systems. It also presents a classification proposal and possible metrics for assessing their structural performance. The chapter emphasises the importance of considering material-related, kinematic, geometrical and mechanical aspects in the design of adaptive façades. The goal is to develop standardised and reliable procedures for the mechanical and thermo-physical characterisation of these novel structural systems. In the same vein, Bedon et al. [47] discuss the importance of experimental testing for adaptive façades, which are building enclosures that can respond to changing conditions. It discusses the performance requirements of façades, including airtightness, water-permeability, fire resistance and structural performance. The study explains that testing can be done in a laboratory or on-site, and that the configuration of the testing should include all relevant details for performance assessment. It also discusses the challenges of testing adaptive façades, such as determining the limit deformations and addressing impact and blast load scenarios. The article concludes by emphasising the importance of certified facilities for testing adaptive façades. Sudhakaran et al. [48] studied the performance of a dynamic façade system in campus buildings. This research involved the application of a climate-adaptive building envelope on a base model and validates and analyses it through thermal simulation and prototype experimentation. The results indicated a noticeable projected energy saving of more than half in annual energy usage (approximately 60% less) as against the normal condition without the adaptive building envelope. It proves that the adoption of adaptive building envelopes that are tailored to the solar movement, incident solar radiation and summer and winter conditions show an improved functioning of the building envelope.

4.1.2 Creating flexible interiors for changing occupancy needs

Flexible interiors improve the functionality of a space and also contribute to sustainability, as they can prolong the life of a building and reduce the need for costly maintenance. One key aspect of creating flexible interiors is the incorporation of adaptable spatial configurations. This comprises the use of movable partitions, furniture and flexible partitioning approaches that allow spaces to be easily reconfigured to satisfy diverse needs. Architects have increasingly turned to solutions such as demountable walls, sliding components and convertible furniture to allow rapid alterations of spaces. These elements enable the swift adaptation of space, for example, an open office into individual workstations, a conference room or a lounge, based on specific requirements. This approach is in sync with the principles of sustainable architecture by reducing the need for new construction when occupancy requirements change. According to Zhang et al. [49] flexible interiors not only reduce construction waste but also lead to lower energy consumption and reduced greenhouse gases associated with construction activities, demonstrating that such design approaches contribute to the sustainability of buildings.

Additionally, the integration of smart building technologies plays a crucial role in achieving adaptable interiors. Sensors, automation and building management systems can be installed to monitor space utilisation and occupancy patterns in real time. This data can inform the dynamic changes in lighting, temperature and ventilation, creating an environment tailored to the existing occupants. Such intelligent systems boost user experience and support the prudent use of space. The benefits of flexible interiors extend beyond commercial buildings. In residential buildings, adaptable interiors allow landlords to reallocate spaces to accommodate changes in family sizes, lifestyle preferences or the need for remote workspaces. This adaptability increases the long-term value of residential properties and aids sustainable living practises.

4.2 Personalising user experience based on real-time data

Real-time data analytics is a vehicle for personalising user experiences. Sensors and Internet of Things (IoT) devices installed in buildings incessantly gather data on user behaviours, temperature, lighting and user preferences. This pool of data serves as the basis for designing spaces that adjust dynamically to the needs of each user. Real-time data permits the customisation of many features of the built environment. For example, smart lighting systems can alter colour intensity based on the time of day, occupancy in a room or user preferences. Likewise, heating, ventilation and air conditioning (HVAC) systems can be adjusted to maintain ideal thermal comfort for each occupant. This level of customisation improves user comfort and also contributes to energy efficiency by curtailing unnecessary energy consumption.

Furthermore, personalising the user experience is more important than environmental controls. Architectural designs are increasingly integrating responsive systems such as flexible partitions and spatial configurations that can be modified to suit particular applications. These systems can be controlled manually or automatically on the basis of data inputs. For instance, an office building might reconfigure itself into a conference room or workstation depending on the user’s needs. Neuhofer et al. [50] identify the requirements of smart technologies for experience creation, including information aggregation, mobile connectedness and real-time synchronisation. It also highlights how smart technology integration can lead to two levels of personalised tourism experiences.

5. Shaping the future of intelligent architecture

5.1 Optimising building performance

5.1.1 Using sensor data to enhance building operations

Sensor devices have become a vital component in the pursuit of intelligent building practises. These devices can monitor a plethora of critical factors, such as temperature, humidity, air quality, lighting and electricity consumption. The data collected by these sensors serves as a valuable resource for architects, builders and facility managers to gain a deeper understanding of the dynamic of building use. One of the advantages of sensor data is that it enhances energy efficiency. For example, temperature and occupancy sensors can work together to regulate the heating, ventilation and air conditioning (HVAC) systems. When no building is occupied, this system can automatically reduce energy usage. Dong et al. [51] demonstrated substantial energy savings through sensor-driven HVAC optimisation. They found that buildings integrated with such systems gain a significant reduction in energy consumption, resulting in both cost savings and less carbon monoxide emissions.

Advanced lighting control systems, for instance, can alter brightness based on the natural circadian rhythms of occupants, thus improving comfort. Moreover, data on indoor air quality can activate ventilation systems to dissipate fresh air when contaminants pass threshold levels, contributing to a better indoor setting. Also, the addition of sensor extends to proactive maintenance. Sensors implanted in critical building systems, such as elevators, HVAC systems and electrical systems, endlessly monitor their performance. By evaluating this data, facility managers can predict when systems are expected to fail, allowing preventive maintenance and preventing downtime. The application of sensor data in architecture can also be scaled to create smarter and efficient urban cities. Cities are increasingly installing sensors to monitor traffic flow, energy usage, waste management and air quality. This data-driven approach informs urban planning and policymakers, paving the way for more sustainable cities.

5.1.2 Improving efficiency and reducing maintenance costs

Efficiency improvements in design often begin with the selection of façade materials. High-performance materials such as double-glazed windows, insulated panels and advanced coatings can significantly enhance the thermal performance of a building. These materials aid in reducing heat loss during winter and heat gain during summer, thus improving energy efficiency. In addition, well-made façades can integrate passive solar systems, exploiting natural daylight while reducing glare and heat gain, consequently minimising the need for artificial lighting and cooling systems. Sheikh and Asghar [52] explore the design of an adaptive biomimetic façade for highly glazed buildings in hot and humid regions. The façade reduces solar heat gain and energy consumption while maintaining visual comfort. The design is inspired by the Oxalis oregana leaf, which tracks the sun’s path and adjusts its position accordingly. The façade module can be folded horizontally and vertically, providing shading under both high and low sun angles. A case study of a 20-story office building in Lahore, Pakistan, demonstrates that retrofitting the façade reduces energy load by 32% and maintains recommended lighting levels in 50% of the interior space. The biomimetic façade offers significant energy savings while preserving visual comfort.

Likewise, the choice of façade materials can impact the cost of maintenance. Durable and maintenance-free materials can reduce the frequency and cost of maintenance. For example, the application of cladding can extend the useful life of façade, thereby minimising the need for regular painting. Façade designs that integrate rain screens and drainage systems can also impede dampness. Integrating smart technologies into façades can further improve productivity and lower the maintenance costs. Automated shading mechanisms, for instance, can regulate changing sunlight, thus reducing HVAC load. Self-cleaning coatings, which can be useful for façade surfaces, can reduce the build-up of dirt, thereby minimising maintenance needs.

5.2 Advancing sustainability

5.2.1 Designing eco-friendly buildings using data-driven approaches

Data-driven approaches include the gathering and analysing of data to inform the design of building façades. Sensors are deployed to collect data on temperature, solar radiation, humidity and wind patterns. This data is then used to make informed decisions throughout the lifespan of a building, from inception to demolition. Through data-driven analysis, designers can determine the effective approaches for increasing natural daylight while reducing heat gain or loss. For example, computational simulations can model the trajectory of the sun during the day and across seasons, enabling designers to position windows and shading devices to enhance daylighting and reduce the need for artificial lighting and cooling. Hosseini et al. [53] underscore the benefits of data-driven daylighting approaches in façades. They assess the concept of an interactive façade that can dynamically adjust to optimise daylight and enhance occupant comfort. The study develops a kinetic interactive façade that can transform based on dynamic daylight and occupant position, improving visual comfort. Daylight parametric simulations demonstrate the high performance of the kinetic interactive façades in improving visual comfort and controlling solar radiation. The results highlight the multifunctional aspects of the façade, which can prevent thermal discomfort and improve occupant health.

5.2.2 Reducing carbon footprints and energy waste

Buildings are responsible for a significant share of global greenhouse gas emissions. In the United States, they account for over 35% of the overall energy utilised and greenhouse gas emissions [54]. Façades, as the main barrier between the interior of a building and the building’s exterior, can overcome these environmental impacts. Energy waste is a direct impact of unproductive building practises. The poorly designed façades can lead to excessive heating and cooling loads, resulting in higher energy utilisation. Architects contribute to the energy efficiency of buildings by minimising energy consumption through façade design. Reducing carbon greenhouse gases aligns with sustainability goals. Sustainable architecture aims to design buildings that harmonise with their surroundings, use resources prudently and have less negative environmental impact. Green façades are the cornerstone of this approach.

Façades should integrate advanced insulation systems and techniques to reduce heat gain/loss. Good insulation minimises the need for heating and cooling, thus minimising the use of energy. Selecting energy-efficient glazing materials with low U-values and better solar heat gain coefficients can considerably enhance the performance of façade. Integrating vents into façades enables natural ventilation, lowering dependence on HVAC installations and reducing energy usage. Using exterior shading components such as sunshades, louvres and brise-soleil can prevent extreme heat gain while allowing natural lighting and reducing the demand for artificial lighting and ventilation. Incorporating renewable energy sources, such as photovoltaic cells into façade design can generate clean energy. Sensor-driven can be used as an automatic control for lighting, heating and ventilation based on user conditions. Assessment of façade materials and the construction technique through life cycle assessments to ensure they have minimal environmental impact over their intended life. Bui et al. [4] propose a computational optimisation approach to improve the energy efficiency of buildings through the design of adaptive façades. Adaptive façades can adjust their thermal and visible transmittance according to changing climatic conditions. The approach combines a building energy simulation programme with an optimisation technique to design the adaptive façade system. The modified firefly algorithm is used in this study, but the method is not limited to a specific optimisation tool or building type. The proposed adaptive façade system is validated through two case studies, showing energy consumption reductions of 14.9–29.0% and 14.2–22.3% compared to static façades. This highlights the potential of adaptive façades to enhance building energy efficiency.

5.3 Innovating occupant-specific buildings

5.3.1 Designing spaces that are tailored to individual needs and preferences

The pursuit of designing spaces personalised to person’s preferences denotes a fundamental shift in design philosophy. This is evident in the design of building façades, which serve as a link between the built environment and its occupants. Contemporary architects recognise that tailored spaces not only improve user satisfaction but also contribute to enhanced health and safety. Individual spaces are intrinsically user-specific, providing buildings that suit the unique requirements of users. This improved individual experience contributes to comfort, satisfaction and a sense of ownership over the space. Designing façades with personalisation in mind helps improve space allocation. Spaces can be modified for numerous functions, accommodating different tasks and dynamic requirements with minor refurbishment. Individualised spaces have been shown to positively impact welfare and productivity. For example, a well-lit space with adaptable lighting can minimise eye strain and increase awareness, whereas customisable interiors help relaxation. Spaces that are personalised to person’s preferences tend to be used more efficiently. This can reduce resource utilisation of energy, water and materials are assigned based on actual needs rather than standardised norms [55].

User-specific design begin by conducting extensive user research to understand the specific requirements of the building’s occupants. This information underpins the design decisions. Integrating spatial shapes that allow easy adaptation. Use partitions, modular furniture and versatile zoning strategies that can be adjusted to accommodate different activities and user preferences. Customisable façade elements that enable customisation, for example integrating windows, adjustable shading devices and balcony spaces that can be tailored to suit person’s requirements. Material and finish choices offer options for interior elements such as the floor, wall and cabinet. This enables users to choose finishes that match their needs. Lee et al. [56] assessed control strategy for adaptive façades, specifically movable shading devices. The aim is to determine the optimal positions of the shades based on various control objectives such as daylighting, thermal comfort, glare prevention and energy conservation. Lee et al. [56] propose a multi-purpose control strategy that considers all these factors and aims to optimise heating, cooling, lighting energy and glare. The strategy aims to provide an effective and efficient solution for controlling adaptive façades.

5.3.2 Enhancing productivity and well-being

Increasing the use of daylight is a vital aspect of façade design. Well-placed windows, skylights and glass façades permit natural light to infiltrate into internal spaces, minimising the need for man-made lighting. Exposure to daylight has been associated with enhanced mood, reduced stress and improved productivity among building users. Façades that offer access to views of the natural environment, such as green areas, parks and water bodies, can have a positive impact on welfare. Research demonstrated that views of nature can reduce mental fatigue and improve cognitive function. Façades play a critical role in adjusting the thermal comfort of a building. Better insulation, shading materials and cooling techniques can help achieve thermal comfort annually. A comfortable indoor environment supports productivity and mitigates elevated temperature-based health problems. Façades can also contribute to acoustic performance by decreasing outdoor noise penetration. Noise-resistance components and glazing can provide a noiseless internal environment, minimise disturbance and anxiety and improve awareness and comfort. The aesthetic qualities of a façade, including its design, colour and texture, can influence persons’ perception of the space. An appealing façade can offer a sense of self-importance and identity among individuals, positively impacting their welfare. Allowing occupants some level of control over ventilation, and lighting can contribute to a sense of comfort. Customised control allows occupants to regulate their environment to suit their needs, thus, improving well-being [57]. Hongisto et al. [58] investigate the relationship between the physical environment of an open-plan office and employee satisfaction. The researchers conducted a quasi-field experiment in a 135-employee office, where various refurbishments were made to improve thermal conditions, visual and acoustic privacy, ergonomics, interior design and spatial density. All employees were surveyed twice, before and after the refurbishment, and physical measurements were taken. The study sought to provide evidence of the impact of the office environment on job.

6. Conclusion and areas of future research

6.1 Conclusion

In conclusion, the incorporation of façade sensors into intelligent architecture represents a transformative leap forward in the way buildings are designed, constructed, operated and maintained. Façade sensors, including temperature, humidity, light, air quality, solar radiation and occupancy sensors, provide architects with a wealth of real-time data that empowers them to design buildings that are not only energy-efficient and sustainable but also user-centric and responsive to environmental conditions. The use of these sensors enables architects to make data-driven design decisions, resulting in more efficient and environmentally friendly buildings. By harnessing the capability of sensor data, architects can optimise energy consumption, improve indoor comfort and reduce their carbon footprint. These sensors facilitate the development of dynamic façades that adjust to vary weather conditions, offering occupants a more comfortable and visually aesthetic environment. In addition, the seamless integration of sensor data within architectural design process, fosters teamwork and interdisciplinary approaches, bringing together design, technology and sustainability. However, it presents challenges such as the control of a large volume of data and the need for architects to embrace computational design approaches and data visualisation techniques.

As we dive into the future of intelligent architecture, it is clear that façade sensors will continue to play a critical role in configuring buildings that are at the core of sustainability, user experience and productivity. By leveraging the insights gained from sensor data, architects can design buildings that satisfy current needs and contribute to a more sustainable and resilient future. The journey towards intelligent architecture is ongoing, and façade sensors will remain at the forefront of this transformative evolution, driving innovation and enhancing the built environment for generations to come.

6.2 Further research

There are numerous areas for further research that can offer a better understanding and extend the application of façade sensors in intelligent architecture. Further studies can investigate the following: [1] how nanoscale sensors can provide real-time data on structural health, air quality and other parameters without changing the appearance of the façade, [2] how 3D printing can be used to produce personalised building components with built-in sensors, allowing for highly personalised and responsive architectural designs and [3] how blockchain can improve data integrity, privacy and transparency in multistakeholder environments. Finally, how sensor-installed buildings can contribute to early warning systems, rapid response and post-disaster recovery efforts, thereby improving urban resilience.