Today, ongoing discussions on climate change, depletion of fossil fuels and energy efficiency emphasize the need for a more sustainable built environment and thus the need to reduce energy consumption in buildings and urban textures and reduce greenhouse gas emissions. Therefore the evaluation of building energy performance with a holistic approach, taking the effect of urban textures and microclimates into consideration has become very significant in the recent years. Urban texture is a commonly accepted expression including the form and height of buildings, the width of streets, their orientation, spatial configuration and arrangement in space intersection, vegetation and so on. This study aims to develop and suggest a model which allows the evaluation of the level of effects of the design parameters which should be considered at the scale of urban textures, on the energy performance of buildings to design sustainable, energy efficient built environments. In the first stage energy performance of a reference building modeled in different urban texture alternatives was evaluated. The evaluations are performed through DesignBuilder simulation program for the location of İstanbul representing temperate-humid climatic region. The parameters of aspect ratio (H/W) and orientation were used to develop different urban texture alternatives. In the second stage, analyses of outdoor thermal comfort of the existing condition and the condition with the added effect of vegetation for the alternatives with the lowest overall energy consumption were conducted with the ENVI-Met program. The thermal comfort parameters of air temperature, mean radiant temperature, wind speed and physiological equivalent temperature (PET) index were used to evaluate outdoor thermal comfort in streets. As a result, the urban texture alternative which achieved the optimum result for energy performance and with regard to outdoor thermal comfort was determined.