For my scene, I used the dome light and added a sun to it, but it only lights up the outside. I used two mesh lights, which were just two primitive boxes that I resized and added to the ceiling of the pad. I have 3 walls and a ceiling in the scene, and they block the sunlight, so I added the mesh lights to make it look like the inside is lighted. The door is open and sunlight is coming through the open door.

I did an initial render and it turned out grainy. I upped the sampling and am rendering again. If it's still grainy I will change the settings on the lights.

If I had a nickle for ever time a woman told me to get lost, I could buy Manhattan.