Abstract: There is disclosed a sunscreen and thermal insulation assembly which may be constructed on site, formed by a screen frame base having an upper end and lower end terminating in a lower nose end having gripping means associated therewith, the screen frame base also including locking means formed thereon, a screen frame insert having an upper end terminating in a top edge and a lower end terminating in a lower nose end having second gripping means associated therewith, the screen frame insert having mating locking means formed thereon for mating engagement with the first locking means of the screen frame base, and also including mounting means formed thereon, a glass frame section adapted to carry a glass panel having mating engagement means for mounting with the mounting means on the screen frame insert, each of the screen frame base and screen frame insert and glass frame sections being adapted to be cut into correspondingly equal sections thereby to create an assembly which may overlie an existing window to f