If we imagine a sealed unit, first we have the inner pane of glass, which in the UK is most commonly 4mm toughened, we then have a cavity or space which is commonly 20mm in the UK, the cavity or space is achieved by using a 20mm spacer bar, as can be seen in the diagram below or to the right, the spacer bar runs around the edge of all 4 corners of the sealed unit, so that when the sealed unit has been installed it is out of view.
Finally, we have the outer pane of glass, which again is 4mm toughened, this gives us a 28mm thick double glazed unit, as two panes of glass have been used. An integral blind is exactly what has just been described, it is a sealed unit for windows and doors, the difference is that an integral blind sealed unit has a blind that has been inserted and sealed into the cavity of the sealed unit.
The standard thickness of sealed units in the UK is 28mm, two 4mm panes of glass and a 20mm cavity, this is perfect for us, as a 20mm cavity allows enough space for our blind to fit and operate without issues, our integral blinds require a minimum cavity of 16mm, anything below that and it is not possible for a blind to fit in the cavity of the sealed unit.