So here on the left, I put in some directional light meant to represent sunlight. Things in Maya default to creating no shadows. Once I turn on shadows, I get what you see on the right. I'm trying to light this like it's during the day so it's still a bit too dark.
Then I made three area lights and placed them over each window. They aren't as bright as the sunlight but they give a nice amount of diffuse light and break up the stark shadows. That's what you see on the left. The shadows are still a bit too dark though. Maya has multiple rendering systems. The default one doesn't have the best lighting effects. Light doesn't bounce off objects so that's why the shadows are so dark. I switched over to a more light focused renderer and I get what you see on the left. Light now bounces off objects and lightens the shadows.
Now it's suppose to be daytime and outside looks a little black cuz nothing is out there. So I created a big background screen and downloaded a panorama to place onto it.
Then with a few more tweaks here and there, I get this end result. A decrepit hospital never looked so nice.