A customizable glass wall system is disclosed. The system comprises at least two glazed, transparent panes mounted to a frame, which is preferably less than five inches thick. The frame includes a removable headboard whereon multiple rollers are mounted. A film is attached to each of the rollers. The films can be selectively extended and retracted behind the transparent panes in the glass wall system by means of the rollers. Each of the films can be controlled individually by a motor driving each of the rollers. The films can be arranged in any combination to perform various functions, but most importantly, to allow various amounts and types of light to pass through the window system in order to control the thermal insulation of the glass wall system. The system can be automated based on time, amount of sunlight, weather, temperature, and user preference.