It's pretty basic. There's not much use for it when you can make all this and more in five minutes. The windows don't have sills, the doors don't have frames/aren't prop_door_rotating, and the warehouse is just a big empty block carved out.
Did you at least shore up the edges of the walls so that they meet at 45 degree angles to lower the t-junction count? Did you use nodraw on unseen parts?