Doors exist on the edge of a block, preventing them from linking correctly to glass panes and iron bars which are in the middle of the block. Why not add a new type of door that runs through the center of the block?
Glass doors could be opened by hand or by redstone, and iron bar doors could only be opened through a redstone signal.
Since they occupy the center of the block they would have to partially enter the block in front of them when they swing open. By putting a block in that space you could prevent the door from being able to swing open, which should provide an additional difference between these and regular doors for people to take advantage of in security designs.
Glass doors could be opened by hand or by redstone, and iron bar doors could only be opened through a redstone signal.
Since they occupy the center of the block they would have to partially enter the block in front of them when they swing open. By putting a block in that space you could prevent the door from being able to swing open, which should provide an additional difference between these and regular doors for people to take advantage of in security designs.
Putting it in the center would allow it to match glass pane and iron bar walls.