The Planning & Zoning / Building Department are separate Departments but many of the operations crossover with personnel and functions.  For example, a permit for a swimming pool only involves Planning & Zoning to ensure placement is in an approved area of the property.         

A permit for a room addition most likely will need a permit from both areas. Planning & Zoning will consider room addition location. The Building Department will be involved with the actual construction of the room addition.

Technical Terms and Definitions for Planning and Zoning

Commercial Building & Contractors(blue): Residential Building(red): Before You Build(white):

Toole & Associates

Building Inspector-Bill Toole