Sustainability has become one of the most pressing concerns of the twenty-first century as rapid urbanisation and increasing consumption continue to place immense pressure on natural resources. In a country like India, where cities are expanding at an unprecedented pace, creating environmentally responsible urban communities has become essential. This concern is reflected in Sustainable Development Goal 11, which emphasises the need to build sustainable cities and communities. In the context of Delhi NCR, where high-rise residential developments are often marketed as modern and sustainable, it becomes important to understand whether these claims align with the everyday experiences and practices of residents. While existing studies largely focus on architectural design and large-scale policy initiatives, less attention has been given to the role of individual households and community-level participation in achieving sustainability. This study aims to examine how residents of Ireo Victory Valley, a high-rise residential complex in Delhi NCR, perceive and practise sustainability in their daily lives. A mixed-method approach was adopted for the study. Primary data were collected through a structured survey conducted among 40 residents of Ireo Victory Valley, while secondary sources provided broader contextual understanding of sustainable housing practices. The findings reveal three key themes. First, residents rely heavily on technology such as air conditioners and air purifiers to maintain comfort, indicating that everyday well-being often depends more on technological fixes than passive design. Second, there exists a noticeable gap between the sustainable features promised by housing developments and the lived experiences of residents, who continue to desire improvements such as rooftop solar systems, rainwater harvesting, and better ventilation. Finally, although residents demonstrate awareness of sustainability issues and express a willingness to support environmentally friendly initiatives, their participation is influenced by practical considerations such as affordability and visible benefits. The study highlights that sustainability in urban housing is not determined by infrastructure alone but by the interaction between design, governance, and resident practices. Strengthening community initiatives, improving maintenance and implementation of sustainable measures, and encouraging greater resident participation can help bridge the gap between sustainable intentions and everyday realities.