WSDS Thematic Track: Integrated Approach Towards Achieving Energy Efficiency and Thermal Comfort Through Active and Passive Interventions

Background Note

As India moves towards Viksit Bharat, enhancing energy efficiency and thermal comfort is crucial, particularly with cooling demand expected to increase eightfold by 2037-38 (ICAP). Addressing rising temperatures, growing energy needs, and rapid urbanization requires an integrated approach that blends traditional wisdom with modern innovations to create sustainable and low-energy solutions.

The integration of Passive and Active—including climate-responsive strategies such as real-time shading systems, hybrid ventilation, and thermally adaptive materials—offers scalable, cost-effective alternatives while enhancing sustainability and energy efficiency. A holistic approach, integrating strategies, technologies, and finance, is essential for equitable and climate-resilient future. Strengthening cross-sectoral partnerships will be key to transforming India's built environment into a global model for sustainable thermal comfort and energy efficiency.

India's rising cooling demand, exacerbated by urban heat island effects and climate change, poses significant challenges to energy security, public health, and environmental sustainability. While passive strategies offer energy-efficient solutions, their impact remains limited without integration with active interventions. The broad adoption of sustainable interventions in buildings to achieve thermal comfort is hindered by financial constraints, technological barriers, and ineffective policy implementation. A holistic, synergistic approach—combining policy support, industry innovation, and research—is essential to mainstreaming climate-responsive, energy-efficient strategies and ensuring sustainable thermal comfort in India's built environment.

India has made notable progress in energy-efficient cooling through initiatives like the Energy Conservation and Sustainable Building Code (ECSBC), Eco-Niwas Samitha (ENS), the National Mission on Sustainable Habitat, and the India Cooling Action Plan (ICAP). Despite this progress, challenges remain in achieving large-scale implementation, high upfront costs of advanced energy-efficient technologies, limited awareness and expertise in passive cooling/heating solutions, inadequate integration of renewable energy systems, and fragmented cross-sectoral collaboration for policy and market adoption. Overcoming these barriers will require strengthening partnerships among government agencies, industry stakeholders, and research institutions to foster innovation and ensure the successful deployment of integrated passive solutions that enhance energy efficiency and thermal comfort in the building sector.

The key objective of orchestrating this session at WSDS 2025 is to foster the role of integrated active and passive interventions to achieve energy efficiency and thermal comfort through cost-effective, climate-responsive solutions. It promotes integrating traditional and modern passive design strategies, optimizing cooling through sky modeling, and scaling up low-cost, energy-efficient technologies. The objectives include raising awareness of energy-efficient interventions, integrating passive solutions, supporting renewable energy, addressing barriers to large-scale implementation, and enhancing cross-sectoral collaborations. The track also aims to advance market adoption, technological advancements, and climate-resilient infrastructure planning to mitigate urban heat island effects and rising cooling demands.

Event Proceedings

The event began with the welcome address from Mr Sanjay Seth, Senior Director at TERI and Vice President of GRIHA Council, welcoming the audience. He emphasized that India’s cooling demand is set to increase eightfold by 2037-38 and that a holistic, scalable, and sustainable approach is essential to tackling this challenge. He set the tone for the discussions, stressing that while traditional passive design strategies are crucial, their impact must be enhanced with modern innovations such as real-time shading, hybrid ventilation, and thermally adaptive materials for a low carbon & resilient future.

Keynote Address: Addressing the Challenge of Scalability:

Following the welcome remarks, Dr Shailesh Kumar Agrawal, Executive Director, BMTPC (Ministry of Housing & Urban Affairs), delivered the keynote address. His speech was a powerful call to action, highlighting India’s rapid urbanization and the urgent need for scalable solutions and strengthening India’s entrepreneurship spirit. He emphasized that affordable housing programs like PMAY must integrate thermal comfort and energy efficiency, ensuring that even the most marginalized communities could benefit from sustainable solutions. Innovation in materials, such as Structurally Insulated Panels (SIPs), AAC blocks, and thermally adaptive facades, would play a crucial role. He emphasized India’s energy transition must be built on a foundation of traditional wisdom and modern innovation as he described low-cost, low-carbon solutions from his hometown, Roorkee, where mud phaska (mud mixed with husk) had been used for generations to regulate indoor temperatures.

Advancing Research-Based Solutions: TERI’s Perspective

Building on the keynote address, Ms Shabnam Bassi, Director of the Sustainable Buildings Division at TERI, provided an overview of TERI’s ongoing initiatives. She emphasized the critical role of research in mitigation, adaptation, and evaluation, highlighting how these elements form a feedback loop that drives meaningful change. Additionally, she introduced TERI’s current research endeavors and collaborations, including its partnership with international glass manufacturers and its policy advisory work under the India Cooling Action Plan (ICAP). She also discussed the development of energy efficiency retrofit manuals for BEE.

Scaling Sustainable Materials: MoU Signing with AACPA

A significant milestone during the event was the MoU signing between TERI and the Autoclaved Aerated Concrete Producers Association (AACPA). Mr Siddharth Bansal, Executive Director, Magicrete, elaborated on the three primary advantages of AAC blocks in sustainable construction:

• Lower U-value, reducing heat transfer and improving insulation
• Recycled content, such as fly ash, decreasing raw material consumption
• Recyclability of construction and demolition (C&D) waste, supporting circular economy principles
• Data-Driven Approaches: The Launch of the Skyscanner Report for Chennai

The event also marked the launch of the Skyscanner Report for Chennai, the second regional study following Gurugram. Mr Ankit Bhalla from the GRIHA Council presented insights on climate-responsive daylighting optimization strategies, which are based on 15 types of global sky conditions. He emphasized the importance of region-specific modeling to enhance building performance. Briefly outlining the instrument’s functionality and the methodology used to interpret the results, further detailed in the report which highlighted that optimizing daylighting strategies through climate-specific sky modeling could reduce energy consumption by up to 25%.

Panel Discussion: Policy, Industry, and Technological Perspectives

The panel, moderated by Mr Sanjay Seth, facilitated a multidimensional discussion on scaling energy-efficient passive and active cooling solutions through regulatory frameworks, technological innovation, and financial mechanisms.

The panel commenced with Ms Pravatanalini Samal (BEE, Ministry of Power) addressing India’s regulatory landscape, acknowledging that while India has a strong framework—including the Energy Conservation and Sustainable Building Code (ECSBC) and Eco-Niwas Samhita (ENS)—ensuring compliance and large-scale implementation remains a key challenge. She noted that while 25 states and UTs have adopted ECBC, full enforcement at the state level is still evolving. Stressing the importance of passive cooling interventions, she advocated for mandating strategies such as cool roofs, improved ventilation, reflective materials, and shading devices in government housing schemes like PMAY, ensuring both urban and rural housing developments incorporate these measures. She also highlighted advancements in active cooling interventions, noting that while over 40 appliances are now included in the standards and labeling program, continuous efficiency improvements are necessary. Citing air conditioner efficiency improvements (from 3.5 ISEER to 5.6 ISEER), she emphasized the need for further enhancements, with a new benchmark expected by 2026.

Following Ms Samal’s remarks, Mr Santosh Dhangar (CPWD) provided an overview of CPWD’s ongoing initiatives to institutionalize energy efficiency in government buildings. He highlighted the upcoming Delhi Schedule of Rates (DSR) as a critical tool for standardizing sustainable construction materials and equipment, ensuring a more streamlined adoption of best practices. Emphasizing the importance of maintenance, he noted that while many government buildings are designed for efficiency, their performance often deteriorates due to inadequate upkeep. He also discussed successful small-scale interventions that have demonstrated significant energy savings, including the replacement of conventional fans with 27W BLDC fans at Shastri Bhawan, the implementation of voltage optimization and sensor-based controls to minimize energy wastage, and the avoidance of over-designed HVAC systems to enhance overall building efficiency.

Dr Kartik Kumar, R&D Director at Saint Gobain Group steered the discussion toward technological advancements in materials and AI-driven optimization, emphasizing the need for greater collaboration between industry, policymakers, and researchers to ensure effective integration of emerging technologies. He highlighted the prevailing fragmentation in policy frameworks, advocating for a more cohesive approach to sustainable construction. Stressing the significance of education in driving sustainability, he underscored the need to raise awareness among architects and consumers about embodied carbon, Life Cycle Assessments (LCA), and Environmental Product Declarations (EPDs), which are critical for assessing environmental impact. Additionally, he challenged the widespread misconception that ‘green buildings’ are defined merely by the use of green glass, calling for a more performance-driven approach that accounts for the entire life cycle of building materials

Building on Dr Kartik Kumar’s insights, Mr Vishal Arora expanded on the role of solar shading in enhancing energy efficiency, highlighting its underutilization in India. He emphasized that industry fragmentation has led to a lack of awareness and adoption of dynamic shading solutions, despite their potential to significantly reduce cooling loads. He particularly discussed the advantages of fabric-based shading systems, noting that fabric like glass has key performance metrics (G-value, U-value) that can be optimized to enhance both thermal and visual comfort. Expressing interest in collaborative research, he proposed integrating Somfy’s sun-tracking systems with TERI’s sky modeling initiative to develop dynamic façade performance strategies tailored to India’s diverse climatic conditions

The final panelist, Mr G N Gohul Deepak from Glazing Society of India, emphasized the critical role of optimized glazing solutions in enhancing energy efficiency. He underscored the need for simplified compliance processes to facilitate broader adoption of advanced glazing technologies. He advocated replacing clear glass with energy-efficient glass in affordable housing and CPWD projects. He also highlighted advancements such as self-cleaning glass and smog-absorbing glass, which offer promising solutions for improving building performance. Additionally, he underscored the need for greater awareness among architects and developers, noting that many stakeholders, especially in smaller cities, still lack a clear understanding of green building principles. He concluded by reaffirming that while the glass industry is well-equipped with cutting-edge technologies, ensuring large-scale implementation remains a key challenge

Bringing the discussion to a close, Mr Sanjay Seth emphasized that while technical solutions and policy frameworks exist, the real challenge lies in translating insights into action. He stressed the importance of bridging the gap between research, regulations, and implementation by fostering stronger collaboration among policymakers, industry leaders, and researchers. The session concluded with a collective commitment to advancing energy efficiency and thermal comfort solutions in India’s built environment.