This paper presents a new methodology to carry out building performance simulation at the district scale integrating the building thermal model TRNSYS with the climate model ‘Urban Weather Generator’ (UWG). The integrated methodology is designed to include the microclimatic modifications induced by urban environments on buildings’ cooling load calculation. The impact of shadows, air temperature increase and urban radiant environment on building cooling performance has been highlighted for hot arid climates (Antofagasta, Chile). Results indicate that the impact of urban context on energy performance of buildings at the neighbourhood scale varies significantly with building typology and urban tissue density