I deal with the planning of middle or lower class houses in Pompeii, and relate the function of spaces with the social structure. I point to the change of social structure from the first century B.C. This change caused the husband and wife's section behind the public area in houses where released servants, craftspeople and shopkeepers lived. The method of analysis is the classification of thresholds. The threshold of the doorway to the back part of the courtyard shared the same characteristics as the entrance threshold. Conclusively these thresholds had the meaning of the division between public and private.
