This research article delves into the transformative potential of repurposing royal heritage buildings into sustainable green ventures. As the demand for environmentally conscious initiatives grows, the adaptation of historic structures provides a unique opportunity to blend cultural preservation with modern green entrepreneurship. The article explores case studies, innovative strategies, and the broader implications of such initiatives on sustainability, local economies, and heritage conservation. The case studies included in this research are mainly from Tamil Nadu adapting the vernacular method of Dravidian construction techniques. It is also an overview of the global shift towards sustainable practices, Heritage Preservation and Cultural significance in entrepreneurship. Exploration of various green entrepreneurship models applicable to historic structures showcasing the sustainable design principles applicable to heritage building renovations. Examination of cutting-edge technologies enhancing energy efficiency and environmental performance. Recommendations for best practices in balancing heritage preservation and green entrepreneurship. This research article aims to provide a comprehensive overview of the intersection between heritage preservation, green entrepreneurship, and sustainable development, offering insights for scholars, practitioners, and policymakers interested in this evolving field.