This new home under construction in Ontario is using LiteZone® L0679 insulating glass units (4.4" thick) in a "frameless" installation for the fixed windows to enable it to achieve a "Passive House" standard. The strength of the fiberglass spacer used in the construction of LiteZone® IGUs allows the use of a simple silicone "Butt Joint" detail (see below) at the vertical edges between two LiteZone® IGUs when set in a strip configuration as shown in the above photos.