I took a short trip to your world:
And its promising. The map is very small, but it shows that U will probably do some really cool stuff some day.
Now, some pointers:
1) The wall brushes go into each other... this causes a flickering effect where they occupy the same space.
Change this:
| |
|_|___
L_|___
...to this:
| |
| |___
|/____
( damn, I'm an ASCII artist

)
Never let brushes occupy the same space.
( And put the comon/caulk texture on the "/" part of the brushes, where the brushes meet that is... )
2) The doors. Nothing technically wrong with them ( love that they dont auto-close ), but the door width is too small, looks unatural...
3) Access to outside. Yes hidden trap-doors are cool, but to make the only entrance / exit to a shool a hidden trap-door is a bit strange to me

. Try to think like an architect. Make your architecture logical.
4) A warning: when this map grows, there will be a danger in letting such complex brushwork as the classroom ( with all the good looking chairs ) be seen from the outside. No problem now, but with a few more such rooms and a larger outside area, the brush count will become very large ( dont panic and redo suff, just keep it as a warning in the back of your head ).
I made
a tutorial out of the first architecture I constructed: An old saw-mill. It follows the construction in nine steps.
Keep it up: Its not a good map now, but it shows promise of a future rock'nroll mapper! 8)