Abstract: A thermal insulation packet for fitting into the space above a basement wall between floor joists adjacent the outside wall of a building structure includes a substantially enclosed, discrete packet containing a body of insulation material. The insulation packet is sized to fit in a space defined, on the bottom, by the top of the basement wall, on the sides, by a first floor joist and an immediately consecutive second floor joist and, in the back, by the outside wall of the building structure. The thermal insulation packet is also capable of being installed by an installer without physically contacting the body of insulation material contained with the packet.