Connecting building density and vegetation to investigate synergies and trade-offs between thermal comfort and energy demand – a parametric study in the temperate climate of Germany

Climate change and increasing urbanization call for combined mitigation and adaptation measures. Therefore, this work shows a method to investigate affected aspects of urban space for their synergies and trade-offs. The focus lies on the interaction between building density and urban trees, as these are essential parameters for possible solutions. The combined, parametric simulation of indoor and outdoor spaces provides a more complete picture of the behavior of individual assessment aspects (e.g. indoor and outdoor thermal comfort, building energy demand). Overlaying the results allows us to identify interactions and to conclude on the effect of interventions such as building refurbishment. In this study, we apply the workflow to a generic neighborhood in Germany. Our results demonstrate a simultaneous behavior of indoor and outdoor thermal comfort, whereas there is a trade-off for heating energy demand. Increasing energy efficiency mitigated this trade-off in some density-green-space configurations. Our case study suggests the combination of green and gray interventions for achieving synergies that contribute to the sustainable transformation of the urban building stock. We conclude that during early planning phases, synergy potentials and trade-offs are already identifiable but context-specific, giving perspectives for further research in this area.