In order to address concerns on buildings energy efficiency and their sustainability in urban development, there is a necessity to identify solutions that contribute to improve buildings thermal performance. Green roofs and green walls are nature-based solutions which contribute to improve buildings´ thermal performance and reduce energy consumption for heating and cooling. However, their effectiveness is influenced by variations in their design, material properties, and thermal characteristics. The focus of this study was to collect and analyze the thermal characteristics of different types of green roofs and walls. A bibliometric analysis of the existing literature was conducted using an adapted PRISMA approach to review the thermal characteristics of extensive, semi-intensive, and intensive green roofs, as well as living walls and green facades. The study focused on variations in design, material properties, and specific parameters such as thermal resistance, thermal conductivity and U-values. The findings provide a comprehensive overview of the thermal characteristics of green roofs and walls, emphasizing their variability across different system types. This demonstrates the necessity for updated construction regulations to facilitate the effective adoption of these systems in urban development, ensuring their optimal thermal performance and contribution to sustainability goals.