This paper describes a new aircraft concept, where all windows, except those for emergency exits, are replaced with simulated windows, which consist of monitors connected to external cameras to overcome the discomfort for the passenger due to the absence of real windows. This concept is developed through an analytical method to estimate the potential advantages for the environment and for airline companies deriving from a windowless configuration for a short-medium range aircraft, within the boundaries of the preliminary design. Actually, the reduction in weight is directly linked to the reduction in fuel consumption, providing advantages in terms of operating costs and emissions of carbon dioxide. The method is applied to four models of short and medium range aircraft, namely Boeing 737–800, Airbus 320, ATR72 and Embraer 190. The results show the benefits of a windowless configuration that become very positive for the operating life of an aircraft and the total fleet, potentially leading to the saving of millions of tons of carbon dioxide every year when applied to the whole fleet of the analyzed aircraft.