So you should have already seen Ex Machina because it is great and everyone has been telling you to, but if you haven't this is what you would be missing:
The film takes place in a secluded modern mansion, and its expansive finished basement. From a set design perspective, what is most interesting is how the basement sets (most likely filmed on a sound stage) tie into the upper home.
The basement level has atriums that mirror the nature in the upper level. They are lit to look like sunshine coming down a shaft, so it helps you orient yourself in the space.