Who is Renzo in the novel, The Address?

Renzo is the Italian supervisor of the Dakota in the 1980's, during Melinda's renovations. Melinda forewarns Bailey ahead of time about Renzo's gruff attitude, but Bailey and Renzo begin to spend more time together investigating the artifacts in the building's basement. Renzo and Bailey discover that they are going to the same AA meetings, and help each other maintain their sobriety. Per AA recommendations, Renzo waits until Bailey has been sober for a year before pursuing a relationship with her, in the final scene of the book.