Green Roofs and Green Walls as Heat Stress Mitigation Strategies for New Delhi, India

Abstract

New Delhi, India's urban environment is grappling with escalating challenges posed by rising heat stress, exacerbated by urban heat islands, rapid urbanization, and deteriorating air quality. This master's thesis underscores the urgent imperative of implementing green roofs and green walls as nature-based solutions to combat these pressing issues. Green Roofs and Green Walls are sustainable building elements that incorporate living vegetation to enhance environmental benefits and aesthetic appeal. With climate change projections indicating an increase in the frequency and duration of heat waves, posing grave risks to human health and the environment, the adoption of these solutions has become paramount. At the building scale, these solutions not only reduce energy consumption, and enhance insulation properties which ensures thermal comfort for residents, but also foster microclimates that lower air and surface temperatures, manage stormwater, boost biodiversity, purify the air, enhance well-being, improve aesthetics, mitigate noise pollution, and store rainwater for future use. On a citywide scale, the adoption of green roofs and green walls contributes to the mitigation of the urban heat island effect, maintaining clean air in the city, reducing noise pollution, combatting smog, promoting sustainability, and enabling cities to be resilient and future-ready by mitigating and adapting to the effects of climate change. This thesis takes a comprehensive approach by meticulously examining various critical factors that underpin the successful adaptation of green roofs and green walls to the unique climatic conditions of New Delhi, India. It delves into the intricacies of substrate selection, plant species suitability, water dependency, and other essential considerations, all supported by scientific studies. By encompassing both small-scale and large-scale factors, this research aims to bridge the gap of uncertainty surrounding the integration of green infrastructure in the cities. The overarching aim of this thesis is to offer practical insights and actionable knowledge to a diverse audience, including architects, designers, urban planners, developers, and other stakeholders. Through an evidence-based approach, this research seeks to empower these professionals with the tools and information needed to confidently integrate green roofs and green walls into their future projects. This study examines how the deployment of green roofs and green walls can alleviate heat stress in New Delhi. It incorporates the proposal of a design case tailored to the specific climatic conditions and urban context of New Delhi. This study aspires to be a catalyst for the widespread adoption of green technologies, fostering sustainable urban development and addressing the pressing challenges of heat stress, urbanization, and pollution in the city. Furthermore, the implementation of these nature-based solutions aligns with the broader goal of advancing sustainable living practices and reducing the carbon footprint of buildings. This research underscores the transformative potential of green roofs and green walls in reshaping the urban landscape of New Delhi, making it healthier, greener, and more sustainable for its residents while offering valuable insights for cities worldwide facing similar challenges.