Double-pane insulating glazing units

A double-pane insulating glazing unit, the double-pane insulating glazing unit having a single between-pane space and two glass panes, such that the single between-pane space is located between the two glass panes, and the double-pane insulating glazing unit is devoid of a third glass pane and is devoid of a second between-pane space, the double-pane insulating glazing unit further comprising a spacer located between the two glass panes, the spacer being adhered to each of the two glass panes by one or more beads of sealant, the single between-pane space being located between the two glass panes and having a width in a range of from 14 to 21 mm, the double-pane insulating glazing unit having an aerogel layer that is located in the single between-pane space and carried alongside one of the two glass panes such that the aerogel layer is supported by said one of the two glass panes, the double-pane insulating glazing unit having a vision area, the aerogel layer having a perimeter edge that is outside the vision area of the double-pane insulating glazing unit, and the perimeter edge of aerogel layer being separated from the one or more beads of sealant, wherein the aerogel layer occupies less than 50% of the width of the single between-pane space, such that a gas gap is provided in the single between-pane space alongside the aerogel layer, the gas gap having a width in a range of from 10.5 to 13.5 mm and containing a gaseous atmosphere comprising argon or a mixture of argon and air, the aerogel layer having a haze of less than 2%, the double-pane insulating glazing unit having a U factor of less than 0.2 Btu/(h·f2·° F.) but greater than 0.14 Btu/(h·f2·° F.) and a visible transmission of greater than 0.65 but less than 0.76, and the double-pane insulating glazing unit having a transmitted color characterized by an ah coordinate in a range of from 0 to −6 and a bh coordinate in a range of from −1 to 5.