Building Code: A collection of rules that lay out the minimum requirements for structures to safely house humans.

Building Inspector: The individual charged by a municipality to check conformance with the construction documents (and the building code)  on the jobsite.

Building Official: The individual charged by a municipality to enforce and administer the building code. She reviews construction documents and issues building permits. Not to be confused with the building inspector.

Building Permit: The document that declares the construction documents meet the requirements of the building code and zoning ordinance, as set by the building official. Unless you’re in a rural area that doesn’t require a permit, woe unto you if you start building without one.

Certificate of Occupancy: What the building permit wants to be when it grows up. The building inspector or building official issues this after you pass the final inspection.

Construction Documents (CDs): Drawings and specifications that describe a house’s design, prepared with enough detail to document  its adherence to the building code.

Four-Inch Sphere: The Platonic form referred to in building code chapters dealing with stairs and guardrails. Prohibit passage of this baby head–shaped sphere through your guardrails or else fail your inspection.

Termite Infestation Probability Map: A diagram in the IRC that shows where termites have set up camp in the USA.

Zoning Ordinance: The document, specific to your municipality, that tells you how tall your house can be, how far it has to be set back from the street, and if you can run a business there.