Well, frankly, this map could use a bit of work. For starters, I understand you're trying to get the lighting just right by adding the skybox texture around the map to produce light through the windows, but the way you implemented it is incorrect and would cause lag on some computers. You may not have a leak, but it sure looks that way. If you want to know how to correctly implement a skybox, I suggest you read this tutorial.

Other notes, this map is waaaay too big. I think all but the ground floor and basement should be cut. I like the elevators, they're nice, but the spaces are just too big to make them work running up the stairs to get to. Also, if this is for HL2DM, where are the weapons? It's no fun to run around a map with no ammo left.

If this map is supposed to be a recreation of a real building, then I wouldn't sell it as a hl2dm map. Textures are all too bland and the same to make any of the areas stand out from one another. I apologize if I'm being a bit rude; it's been a long day for me, and I suppose I'm look'n to get it all out over the internet

The map could survive the test of time if it had a trimmed layout and implemented more gameplay mechanics. Other than that, it doesn't look like anything special, but nevertheless, it does have lighting in it, so I'll give it a 2 star rating for that. I like the generators in the basement and the elevators the most. They add the most character to the map. Keep it up though, it looks like you're gaining experience from every project, and I look forward to seeing your future work.

Yes it is, the building was built in the 1937, so as we all know during that time everything was built large scale. I figured to try and do it on the same scale.
Also I haven't completed all the walls and doors yet it's really very incomplete at this time. I'm trying to pull all this from memory as I said and plan on adding more to break it up and make the gameplay better.
I wanted to keep the building as true as I could to the original simply for the reason that I didn't feel making it smaller did it justice, but maybe after this is done I'll shrink it some and see if it works better as a gameplay map.
Yeah the lighting is kinda weird I agree. I have experimenting with it and it's definately not finished.
I figured this would mostly be for as I said large groups of players or team play. Hopefully it will work in that way.

So this is a 1:1 real-world remake of a building? Those can be tricky.

Kudos for taking on such a large project. Unfortunately, I have to tell you that doing real-world buildings (parts are OK, but entire buildings) hardly ever works out, gameplay-wise. It's too large, there's too little cover and, naturally, most spaces are empty "filler", which should generally be avoided. It has a lot to do with the Source engine's weird scale, which makes real-world proportions often impossible (better adjust everything to standard texture heights for walls, doors, etc... and make compromises).

Be happy with what you have, I'm sure it's fun to run around. But keep the scale down for your next project, in order to improve flow. Consider cutting off a few too open or redundant areas to focus gameplay somewhere interesting. Make sure there are a lot of "choices" (left or right mostly) available to the player almost constantly. If you can only move "forward" for more than 5-10 seconds it feels restrictive. I try to have a choice of paths available to the player at least every 3 seconds when moving through a dm-map at full speed.

Your lighting looks weird because you mostly used plain white (RGB 255, 255, 255), which tends to look gray and lifeless in combination with HL2's texture set. Give your lights subtle shades of yellow or blue to get some color contrast. Use down-facing "light_spots" (with a large "constant" value of 5000 or more) to avoid the ceiling being over-bright from standard lights. Like in this pic, but for all lights: To make light fall in from the sky, add a "tools/skybox" texture to the outer part of your windows, put a transparent texture in front of it and then set a bright value for a "light_environment" entity letting it come in from a lower pitch (-60 or so).

Also, you almost certainly have a problem with vrad/compiling. The above screenshot shouldn't have such dark ceilings. The light should "bounce" off the floor and subtly brighten the ceiling. Probably you do have a leak (causes vrad to light without bounce). Or you're running vrad at too low settings. The render doesn't look final because of this.

Anyways, keep on rockin/mapping!

No Leak it's how I set the lighting up to get that light from outside to come thru the windows. I'm not a big fan of the lighting in Source. I used white light and func brushes for the lighting with nodraw to close them off from areas.
Yeah it's a pretty big map, amazingly the architexure is large scale in the building it had huge doors and rooms and...well it was just built large. it's most likely a map for large groups of players.
I plan on adding alot more to break it up so hopefully it will be more challenging.

The architecture look realistic and entertaining. Thought the scale might make play difficult.

The lighting in the pics leads me to believe you have a leak somewhere in your map.

Oooppps! It's not a Call of Duty map it's a HL2DM map.