aight i expanded my rooftop and made sure that i no leakage. then I put a light near the top of with an area of 2000 (to simulate sunlight) however whenever I compile i still get an entity leak from it.. now does the full area of the light have to be within the room or I need to check the walls again... i tried this several times still get the damn leak debug msg.

ALL your entities need to be INSIDE the hull of structural brushes surrounding your map. If you click File > Pointfile... from the GtkRadiant menu, you'll get a red line that traces from the first entity that the compiler saw through the leak out to the leak in your map. If you get a leak, load the pointfile, filter detail (CTRL + D), entities (ALT + 2), and patches (CTRL + P), then follow the pointfile until you spot the hole in your map. Plug it with a strucural brush.

If you want a good sun effect, use one of the sky shaders that incorporates a sun light. It will have a line of code mentioning a sun...you won't miss it.

use a sun light entity
theres a tutorial on map review