For future reference, use the Team HQ layout for indoor parks, it seems to have the best lighting. That being said, it would be really hard to put a roof on the DC Embassy and get it right.
I am going to go out on a very sturdy limb and say that Unless someone figures out a glitch that adds a considerable amount of terrain to the terrain limit....the roof will never be spot on while also having the park be spot on. Sad, but true.