Low driving range is one of the main obstacles for a larger market penetration of future autonomous Electric Vehicles (EV). HVAC system size and consumption can lower the range of an EV from 5% to 50%, depending on the outside weather conditions, vehicle size, vehicle envelope characteristics and driving style. In the context of the a research project with Italdesign, it was investigated the impact of vehicle envelope design and characteristics on vehicle performance on one hand, that is driving range for EV and HVAC size and emission for internal combustion vehicles, and vehicle occupant comfort on the other. In particular the design of the transparent and of the opaque envelope of the vehicle was investigated, considering innovative and switchable glazing technologies as well. The study was carried out by means of a sensitivity analysis on vehicle envelope characteristics, by means of a dynamic thermal model which was tested in two conditions, static summer conditions with presence of solar radiation and dynamic conditions (pull-down test for cooling, summer, and heating, winter, conditions). The results show that by optimizing envelope characteristics, by adopting smart glazing and high performance insulation, the size of the HVAC system can be largely reduced (up to 70%) by maintaining even higher comfortable level inside the vehicle (maximum perceived temperature reduced by nearly 40°C). Moreover this can impact the driving range for EV from 11% to up to 27%, depending on the vehicle average speed. This result is particularly important for material and component manufacturer supplying the automotive industry, and could positively impact on a deeper penetration of EV in the mass market.