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Windows account for 30—10°% of heat exchange across building envelopes and contribute up to 25-30% of total HVAC energy use. Conventional coatings offer limited adaptability to seasonal variations. This study investigates scattering-based spectral-selective glazing strategies within the solar spectrum, with an emphasis on the optical mechanisms governing visible transparency and near-infrared (NIR) heat-gain suppression. A mechanism-driven modeling framework is developed using Mie scattering analysis to examine how particle size, refractive-index contrast, and core-shell configurations affect wavelength-dependent scattering and extinction behaviour. These scattering-based pathways are positioned relative to absorptiondominated thermochromic approaches for dynamic NIR modulation. The results highlight physical trade-offs: while larger dielectric particles enhance NIR shielding, they introduce significant visible haze. Core-shell architectures are shown to partially decouple these effects by engineering effective refractive-index contrast. The findings establish a theoretical foundation for bridging nanoparticle optics with building-scale performance evaluation, identifying design boundaries for future climate-adaptive glazing systems. 

With continued urbanization and the increasing occurrence of extreme weather events, urban areas have become more vulnerable to environmental and infrastructural challenges than in the past. A key concern in this context is the Urban Heat Island (UHI) effect. It is primarily driven by two factors: solar irradiation— which includes both direct sunlight and indirect reflections or re-radiation from building facades and urban surfaces—and anthropogenic heat, such as emissions from vehicles and waste heat from HVAC systems. Among these, glazing façade play a pivotal role by interacting with solar radiation, emitting surface heat, and contributing anthropogenic heat through HVAC systems, collectively influencing the surrounding outdoor microclimate. The situation is further intensified by certain material choices and designs—such as low-emissivity (Low-E) windows—that are intended to enhance building energy efficiency and indoor thermal comfort but can inadvertently increase solar reflection and create heat traps in the surrounding area. To address the challenges posed by current glazing façade designs and to enhance energy efficiency, thermal comfort, and UHI mitigation in a coherent manner, we propose several innovative alternatives, including Low-E/ATO co-coated double-pane windows, retro-reflective coated windows, translucent windows, and window-integrated greenery or gardens. These glazing façade designs are then tested both experimentally and numerically and benchmarked against other commonly used glazing systems. By examining key performance indicators from multiple perspectives—such as Energy Use Intensity (EUI), Total Solar Irradiance (TSI), and the Universal Thermal Comfort Index (UTCI)—we identify the most suitable design and further derive the optimal design strategy. The results show that with newly proposed Low-E/ATO co-coated double-pane window, modelled urban area could achieve the similar energy performance as the highly reflective Low-E window, but drastically reduce the adjacent ground's TSI (up to 25%) and therefore improve the outdoor thermal comfort (some locations up to 3.2°C UTCI decrease). 

This work investigates the full-spectrum optical and photothermal properties of Antimony Tin Oxide (ATO)-coated glass for application in energy-efficient building glazing. A simple, scalable dip-coating method was employed to deposit ATO films, and their spectral optical performance was characterized across a broad wavelength range of 250 nm–20 µm [UV–Vis–near-infrared (NIR)–mid-infrared (MIR)]. In this study, for the first time, comprehensive optical data, including spectral transmittance, reflectance, absorptance, visible light transmittance, haze, and spectral and total mid-infrared emissivity (5–20 µm), are reported together for the full solar spectrum, along with the photothermal performance. UV–Vis–NIR spectroscopy and Fourier transform infrared analysis were performed for optical characterization, and surface morphology and nanoparticle dispersion were examined using scanning electron microscopy. The results reveal that ATO-coated glass exhibits high photothermal performance with light-to-heat efficiency greater than 65%, while deposition parameters can significantly affect this efficiency. ATO-coated glass shows high transparency in the visible region with strong and tunable spectral absorptance in the near- and mid-infrared regions, which is a critical feature for thermal control in building applications. The ability to fine-tune near-infrared (NIR) absorption through deposition parameters allows for tailored performance suited to specific environmental conditions. In addition, the coated glass shows low reflectance and high total emissivity in the MIR region (>0.9), specifically in the atmospheric window, enabling efficient radiative heat dissipation. By combining the tunable NIR-selective absorption for solar-heat shielding with controllable MIR radiative dissipation, this study identifies ATO as a promising photothermal material for energy-efficient glazed façade technologies. The comprehensive optical data provided in this study are essential for architectural applications and establish a foundation for future research on photothermal materials in building envelope systems. 

Dynamic building envelopes integrated with renewable energy sources, termed Dynamic and Renewable Source Building Envelopes (DREBE), provide an innovative approach to optimizing building envelope designs. Yet, these systems are not mature enough and not widely adopted in the industry and few literature resources are employed to understand them. These systems dynamically respond and adapt to various environmental, energy, and occupancy demands for higher energy efficiency and comfort levels compared to traditional building envelopes while simultaneously producing energy. Their potential in climate change mitigation and fostering sustainable urban development warrants great attention from industry and urban planners. Especially in positive energy districts, which aim to reach net-positive energy goals through utilizing smart energy efficient building systems on the district level. This paper reviews innovative systems like dynamic photovoltaic shading devices and phase change materials and evaluates their performance by answering two research questions, what are the current DBE trends and are they feasible in achieving net-positive energy consumption? The analysis conducted reveals the dominance of solar-based dynamic renewable energy systems and a great need for alternatives. The study suggests that alternatives like wind as a renewable energy source should be studied with dynamic systems. Moreover, the study highlights current research gaps including insufficient data on long-term application and economic costs associated with such systems. To address this gap, the study suggests exploring in depth some of these systems and then branching into various combinations of dynamic envelope systems with multiple renewable or adaptive components to further enhance the overall building performance. By synthesizing the current body of literature, this paper gives insights into advancing the application of the dynamic building envelope systems and highlights their crucial role in the future of sustainable urban environments. 

Building-integrated photovoltaic (BIPV) systems blend energy generation with traditional architectural facade functions, promoting the development of zero-energy buildings by reducing energy consumption, lowering greenhouse gas emissions, and enhancing aesthetic value. Despite these benefits, the integration of photovoltaic technology into building materials introduces challenges, notably in ensuring structural integrity, maintaining thermal performance, and securing long-term durability under diverse environmental conditions. This review examines current standards and building codes relevant to BIPV windows, highlighting the necessity for testing protocols that encompass combined stressors from extreme weather events exacerbated by climate change. Through a case study focused on Singapore, the review underscores the rising frequency of combined heat and wind events, advocating for robust standards and adaptive policies. The paper identifies critical research gaps and proposes future directions to enhance the reliability and performance of BIPV systems, aiming to solidify their role in sustainable building practices. 

Lighting strongly influences indoor well-being, yet existing metrics like "Daylight Autonomy" and "Annual Solar Exposure" overlook circadian light. Research highlights circadian light's significant impact on human performance, creating a need to explore spatial factors affecting its distribution. This study examines the influence of surface reflectance, proximity to windows, windows' optical properties, and gaze direction on circadian light. Using the Lark Plugin for Grasshopper, simulations were conducted in a box-model room with ten glazing systems varying in visible transmittance. The results show that windows with a visible transmittance below 0.3 fail to provide adequate circadian light unless the gaze is perpendicular. Among surface reflectance factors, wall reflectance proved more critical than ceiling reflectance in optimizing circadian light exposure.