The transition from building to district scale is supported numerically by the nascent field of Urban Building Energy Modelling. However, the concurrent assessment of building energy demand and local climate conditions is sparsely studied explicitly, while there is a lack of integrated tools embedding the modelling of district energy systems. This article presents a developed coupled model to account for building energy needs, urban heat island and site-specific effects, along with the district energy system operation. To illustrate the approach, we examine the mitigation potential of a district network under projected climate conditions for a city with an oceanic climate. Key Innovations  Synchronous coupling methodology at urban scale.  Explicit modelling of urban building stock and local microclimate.