So I have been working on a destroyed themed map, which is my favorite type. However, I have always been unsure of my roof destruction details and such. If anyone wouldn't mind looking at a few pictures, I would appreciate feedback.

Here is a link to an imgur album I made.
http://imgur.com/a/vafXi

Looks cool, but it seems like it's a clean chamber that recently crashed into a forest, meaning there's a perfectly clean interior and a destroyed exterior. Try putting some dirt and foliage into the chamber itself. Otherwise, it looks great.

used destroyed textures,
rotate the walls 10 - 25 degrees
add destroyed walls
add more vines, add flopping around panels
add bts textures

What you've got so far looks pretty nice, especially the area outside the map.

Here are a few more tips:

• The subfolder "props_destruction" in the model browser contains lots of broken panels and other junk, which are perfect for a map like this. When placing this kind of loose rubble (i.e. something that is not hanging off a wall or otherwise attached to static geometry), hold down the [alt] key while moving or rotating it to temporarily turn off grid snapping. Real junk doesn't align to a grid either

• To make holes in walls and ceilings look more destroyed or caved in, use the "wall_dest_256x128_02.mdl" and "wall_dest_128x128_02.mdl" models around the edges. For ceiling holes, rotate these a bit (alt!) to make them seem bent downward.

• The light from the sky alone is almost always too dim to light the inside of the map properly. Place some point_spotlights (or even an env_projectedtexture) close to the sky, and point them at the wall / ceiling holes. That way the light still comes from outside the map, but you can control it better. Make sure these match the sky colour.
  (I shamelessly swiped some out of Valve's maps. Don't tell anyone!)

• Lastly (just a suggestion), in the place where you have water trickling down, it would look nice if there's a small pool or flooded area instead of the water just disappearing between the floor tiles.

I'd love to see / play this when it's finished!