Patent ID: 7845142

Claim:
A window unit comprising: an insulating frame in which both an inboard glass lite and an outboard glass lite are partially embedded, the inboard lite comprising a vacuum IG unit including first and second spaced apart glass sheets having the same height, that are separated from one another via a gap that is at a pressure less than atmospheric, and the outboard lite comprising a monolithic glass sheet spaced apart from the vacuum IG unit; wherein the frame comprises insulating material that separates the surface of the vacuum IG unit closest to the monolithic glass sheet from the inner surface of the monolithic glass sheet; wherein along at least one of a top edge, a bottom edge, and/or a side edge of the window unit, the outer edge of the monolithic glass sheet is vertically offset from the outer edge of the vacuum IG unit so that the outer edge of the vacuum IG unit is closer to a periphery of the window unit than is the outer edge of the monolithic glass sheet; wherein a gap between the inboard lite and the outboard lite is substantially at atmospheric pressure, so that the gap on one side of the second glass sheet provided between the first and second sheets is at a pressure less than atmospheric pressure, but the gap on the other side of the second glass sheet provided between the second glass sheet and the outboard lite is substantially at atmospheric pressure; and wherein a total R-value of the window unit is at least about R-8.