The Edmonton Squash Club has a North American Doubles Squash Court with a 24' ceiling.
The initial rationale for installing the doubles court vs a fifth singles court was that it was a great transition game for older members whose knees could no longer take the stress of multiple singles matches in a week. However, it has turned out to be a fun game for players of all ages and incorporates a social element that is not always present in the singles game.
North American Doubles courts are significantly longer and wider than International singles squash courts. The is distinctive from International doubles which is played on a wider court than the singles game.
The official North American Doubles rules can be found here