Outdoor spaces play a critical role in sustainable building design, influencing both human thermal comfort and ecological resilience. Recent sustainability frameworks increasingly emphasize nature and biodiversity integration in urban environments, while established practices continue to prioritize outdoor thermal comfort through well-defined indices and parameters. However, these two domains—thermal comfort and biodiversity—are often addressed in isolation by different stakeholders, such as building sustainability consultants and landscape architects, leading to fragmented design strategies.
This paper explores the potential for a unified metric that synergistically evaluates outdoor thermal comfort alongside nature and biodiversity considerations, providing a guiding principle for integrated design development. The study adopts a comprehensive literature review to identify and analyze key parameters influencing thermal comfort and biodiversity in urban contexts. Based on this review, a preliminary framework for a composite index will be proposed, outlining parameter selection criteria and conceptual formula development. While the primary focus is on theoretical formulation, potential case studies will be referenced to illustrate applicability and validate the proposed approach. The anticipated outcome is a foundational tool to support interdisciplinary collaboration and promote outdoor spaces that are both thermally comfortable and ecologically supportive.