Current thinking is a small/inflatable buried structure with absolute minimal facilities. An inflatable 4 metre diameter tube roughly 6 metre long, laying on its side, buried 2 meters, with two meters of regolith overburden. Say 3-5 bunks on a wall, a couple desks, a RV style shower/head and a small sink. Maybe if we are really lucky a place to heat food. There will probably be three airlocks, one outer lock leading to a suit room, a second lock between the suit room and the living quarters to keep dust down, and a third as an emergency exit. There will be a limited amount of water recycling, and until we get the in-situ resource manufacturing down, most supplies will need to be brought it. Of course power will be supplied by solar panels over the overburden, (A little more protection) and perhaps as a sun shade over some of the external equipment. Power storage for overnight is still in the 'air'. (Sorry)
Click on thumbnails below for two sized illustrations suitable for computer desktop bitmaps, one is 4x3 aspect ratio, the other is widescreen.