Can you "flip" static objects?

[SpiritSharD]

Me again, sorry to be a pain.

Is there any videos on how to accurately place and align walls? I've literally spent hours trying to finish two rooms, but can't progress due to z-fighting issues or gaps.

http://i134.photobucket.com/albums/q84/S...rstmap.png

Where the (poorly drawn) red boxes are I was going to make prisons cells...however I just could not fit the cell doors within the gap, and there were places where you could see through walls etc (in between cells when looking at them from outside). The door in the middle of the map isn't place correctly either.