In urban areas the impact of built environment on wellbeing and human health should be considered due to urban heat island phenomenon. The present research aims at identifying a method for an accurate estimation of thermal outdoor comfort and mean radiant temperature, modeling and simulating the effects of urban form and vegetation on microclimate of cities. In order to reach this main objective, this research incorporates CFD based simulation tool ENVI-met and TRNSYS (Transient Systems Simulation) by means of Grasshopper. The results of the study demonstrate the reliability of the proposed method, i.e. that a combination of ENVI-met and TRNSYS increases the simulation accuracy in terms of outdoor thermal comfort, especially during night. This method allows exploiting the potentialities of both ENVI-met and TRNSYS for the calculation of urban features (urban form, vegetation, canyon proportion, etc.) affecting urban microclimate. (C) 2017 Elsevier B.V. All rights reserved.