The impact of urban morphology on the outdoor thermal comfort has been widely reported, but few studies have inquired into environmentally-conscious urban design (ECUD) to contribute to the development of recommendations and guidelines as a tool to aid urban planners and designers in decision-making. Open Urban Design (OUD) approach is increasingly used in the design of recent residential neighborhoods, complete and continuous joint ownership is rejected to create spaces with optimal solar and light exposures and create through views. However, the suitability of this configuration shall be tested for different climate conditions. This paper focuses on the assessment of the OUD approach at four climate regions of Morocco in winter and summer. The case study is a recent residential district (54 ha). Two scenarios of building sets were simulated for 12 h in Rabat, Errachidia, Tiflet, and Marrakech. At first, an experimental validation of the 3D microclimate model ENVI-met 4.3.1 is performed. Six morphological indicators are then calculated and cross-correlated to numerical simulation results. The impact of urban parameters on the mean radiant temperature (Tmrt) has been investigated; the evolution and the spatial distribution of the average predicted mean vote (PMV) have been presented. It follows that cloudiness, latitude, shading, vegetation, and compactness have a significant effect on Tmrt, and this effect differs from summer to winter. OUD isn't appropriate for the extreme climate conditions whereas, this urban design choice can significantly improve the outdoor thermal comfort in moderate climate conditions depending on morphological parameters and vegetal density.