Urban densification is a way to restrict the world's urban sprawl but it can strongly impact existing buildings’ energy balance. Dynamic Thermal Simulation (DTS) programs are mainly used at a single building scale and tools made for district-scale or city-scale studies mentioned in the literature are unsuitable for high performance building designers. Therefore, building professionals involved in urban densification projects would greatly benefit from a decision-support design tool able to make an energy evaluation of the involved area, taking into account interactions between the new building and the existing district. This paper presents a district-scale intercomparison of three DTS programs that have various capacities to consider local microclimate effects. The results of this study are used to put emphasis on leading heat transfer modes at a district scale and to estimate tools relevance for urban densification projects design aid.