Smoker damage/Paint question

[Nikol Noll]

Flipping my first house and having a difficult time with the painting.  I am using Sherwin Williams products, and regardless of using SuperPaint or the cheaper options, it is taking 3 coats to cover the walls.  There was  a smoker in the house and I am wondering if this is the cause.  However, even the rooms that don't have obvious smoke residue are needing 3 coats.  Any thoughts/suggestions?