According to our records, this business is located at P.O. BOX 1531 in Sebastopol (in Sonoma County), California 95473, the location GPS coordinates are: 38.4021359 (latitude), -122.8238806 (longitude). Holthuis and Associates is categorized under Furnaces, Domestic Steam or Hot Water (SIC code 3433). Known organization owner is Helana Catalano. You can contact the company by phone at (707) 823-3545.