Current highly urbanised cities are severely suffering from urban heat island effects, which become a threat to human health and outdoor thermal comfort. City planners are considering to redraw the urban layouts to make cities better prepared for global heat effects. This research aims to develop green infrastructure design guidelines to improve outdoor thermal comfort in a block scale. The Research Through Design approach will be adopted by integrating evidence-based microclimate modelling into the design process and involving stakeholders in the assessing process. Parametric modelling will first be used to propose prototypes of green infrastructure and urban block layout combinations. Then these prototypes will be simulated for future climate change. Finally, experts and users will make assessments on these prototypes and final design guidelines will be proposed.