That looks really nice so far. I look forward to seeing the rest of them. Some of the vertical lines may be off kilter (front left corner of the interior structure and windows on side facing the main gait/doors). There could be a (very small) line missing (bottom edge of the far wall inside, to show where it meets the ground). You might also want to adjust the weight or strength of some of the line art overall, so that the depth reads better and makes it easier to distinguish between structures and planes (mainly concerned about the top crenelated pieces on the near side that overlap the interior structure).