A draft deck guide including deck plans for each of Endeavour's seven decks has been posted for review and discussion. This is just an initial draft - nothing is close to being finalised yet. The layout is a compromise between crew spaces, machinery/equipment spaces, the location of exterior equipment and the ship's survivability.
The ship's interior is divided into three areas, with the core primary spaces - the "citadel" - the most heavily protected and housing the most critical systems.
Highlights include the (perhaps surprising) amount of space proposed for crew accommodation - each crew member gets their own cabin (even if some have to share a bathroom with another crewmate). This reflects the long, hazardous missions Endeavour is expected to undertake with a mixed military/civilian crew.
The deck guide can be found here, including PDF versions which are easier for zooming into detail. Comment below with your thoughts and suggestions!