Mainstreaming Thermal Comfort for All and Resource Efficiency in Affordable Housing

Introduction

The document focuses on the critical need to integrate thermal comfort and resource efficiency into affordable housing projects, emphasizing the challenges, solutions, and strategies for achieving sustainable and livable housing in India. Below is a detailed summary of its key findings and recommendations.

Context and Importance of Thermal Comfort

Affordable housing often suffers from poor indoor conditions, inadequate thermal performance, and energy poverty. These issues are exacerbated by climate change, urban heat island effects, and economic challenges, leading to adverse impacts on residents' health and well-being5. Addressing thermal comfort is essential for climate resilience, energy efficiency, cost savings, and improved living standards24.

Assessment of Affordable Housing in Telangana

Scope of Study

The study evaluates affordable housing projects in Telangana under the 2BHK scheme. It assesses planning layouts, material choices, compliance with energy efficiency standards like Eco Niwas Samhita (ECBC-R), and the impact of alternate walling technologies on thermal comfort13.

Key Parameters

• Thermal Comfort: Influenced by ventilation, orientation, shading devices, and material properties.

• Daylighting: Examined to optimize natural light in housing units.

• Energy Efficiency: Measured using Residential Envelope Transmittance Value (RETV), which gauges heat gain or loss through building envelopes13.

Findings from Thermal Comfort Simulations

Material Choices

• Concrete blocks are widely used but provide limited thermal comfort.

• Fly ash bricks and AAC (Autoclaved Aerated Concrete) blocks offer better insulation and significantly increase annual thermal comfort hours1.

• Combining AAC blocks with concrete walls enhances both thermal comfort and construction speed. For example:

  • A combination of 100mm AAC with 150mm monolithic concrete blocks adds 114–158 thermal comfort hours annually.

  • Using AAC as exterior walls while employing poured concrete for load-bearing walls allows faster construction while improving comfort13.

Limitations of RETV

The study highlights inconsistencies in RETV's reliance on U-values (thermal transmittance). Materials with high thermal mass perform better in terms of thermal comfort but may not score well on RETV. For instance:

• Compressed Stabilized Earthen Blocks (CSEB) outperform fly ash bricks in thermal comfort despite weaker RETV performance.

• High thermal mass materials should be prioritized for low-rise housing typologies to achieve better indoor conditions3.

Daylighting Analysis

Daylight simulations reveal significant variations in daylit areas depending on site layouts. Units simulated in isolation perform better than those simulated within clustered site conditions. Optimizing layouts can improve daylight access without financial implications or extensive simulation studies1.

Policy Recommendations

Adopting Energy-Efficient Guidelines

The study advocates incorporating ECBC-R standards into state-level housing policies to ensure thermally comfortable and energy-efficient designs. These guidelines should address:

• Orientation for optimal ventilation.

• Use of shading devices like chajjas to limit solar heat gain.

• Selection of materials with better insulation properties14.

Focusing on Material Innovation

Telangana's widespread use of concrete blocks should be supplemented with better insulating materials like AAC blocks. Strategies such as combining AAC with monolithic concrete walls can reduce annual hours of discomfort while maintaining cost-effectiveness13.

Leveraging Thermal Mass

Materials with high thermal mass should be prioritized for low-rise typologies under mass housing schemes like PMAY-U. This approach balances construction speed with enhanced thermal comfort3.

Challenges in Implementation

Barriers Identified

• Lack of data on indoor conditions in affordable housing5.

• Limited awareness among stakeholders about the benefits of thermally comfortable designs.

• Financial constraints in adopting advanced materials and technologies.

Potential Solutions

• Conducting stakeholder consultations to bridge knowledge gaps.

• Promoting innovative technologies like AAC blocks through incentives.

• Integrating climate-responsive design principles into national housing missions45.

Energy Impact Analysis

The study emphasizes the long-term benefits of minimizing energy use through thermally efficient designs. Affordable housing built under PMAY-U can significantly reduce operational energy consumption, contributing to national climate goals4. Key strategies include:

• Using insulation-based technologies for enhanced energy savings.

• Prioritizing materials that balance cost-effectiveness with performance34.

Conclusion

Mainstreaming thermal comfort and resource efficiency in affordable housing is crucial for addressing India's growing urbanization challenges. By adopting climate-responsive designs, innovative materials, and energy-efficient guidelines, affordable housing can become more sustainable, resilient, and livable. The findings from Telangana's case study provide valuable insights into improving mass housing schemes nationwide while aligning with India's environmental goals14.