“The two crises of climate and biodiversity cannot be treated separately, and restoring nature and replenishing biodiversity are essential to absorb and store more carbon” (Fit for 55). The “Carbon Neutral” target is therefore complemented by the “Nature Positive by 2030”: a global and social goal introduced to halt and reverse biodiversity loss. The green transition cannot be achieved without simultaneously meeting both ambitious targets. The approach of “nature-based thinking” and “transformative resilience” moves away from the anthropocentric canons of the traditional sustainable development paradigm. The positive approach to nature aims to reduce the damage that humans might cause to themselves and their living environment when they destroy its intrinsic and extrinsic qualities. Buildings and urban open spaces can make a significant contribution in this direction, and the role of integrated greenery can be significant not only for urban biodiversity but also with respect to the goal of decarbonization (carbon footprint reduction, negative carbon emissions and embodied carbon neutrality). It is therefore essential that for the built environment, the design approach is “nature-based thinking.” The chapter illustrates the outcomes of research into the new frontiers of green-built environment integration to help achieve the Nature Positive goal. It analyses the use of NbS at the three scales (Green Building Sites, Green Building Systems and Green Building Materials), which can offer a wide range of sustainability benefits, both to improve the energy and environmental performance of buildings and to implement an “urban nature” strategy for wider urban regeneration. Inherently nature-based solutions have the potential to improve quantitatively and qualitatively biodiversity. Through the critical analysis of best practices, it is shown that the technological design of NbS, through systemic approaches, can guarantee an effective improvement of ecosystem quality and the achievement of the Nature Positive objective, overcoming the risk of a governance of fragmented implementation processes.