Bid: How much the contractor will charge to build the house. Different than "estimate." ("Bid" is to "estimate" as "getting wife flowers" is to "maybe thinking about getting wife flowers.")
C of O: Stands for Certificate of Occupancy and is required by many municipalities. After the inspections are complete and the permit fees paid, the city gives you one. If you move in without it, you are basically a terrorist.
Change Order: An official authorization that you owe the contractor more than you originally did. Change orders are usually associated with surprises, some good (upgraded appliances!), some sucky (abandoned septic tank!).
Construction Documents: The detailed plans and specifications, developed and stamped by an architect. These are referenced in the contract.
Contract: A document with plenty of fine print that describes the financial and legal specifics of a project. If you’re using a contractor, you need one of these. ("Having a contract" is to "not having a contract" as "family planning" is to "beer bong.")
Kenny: If the contractor or the [something] guy is male, there is a 25 percent chance his name is Kenny.
Punch List: A painstaking, end-of-the-project, room-by-room accounting of all the stuff that’s not right.
[Something] Guy: A contractor may subcontract out work to specialists—–the concrete guy, the painter guy, etc. Note: The term is gender nonspecific, e.g., "That drywall guy is hot. Too bad she’s married."
Stink Eye: The pre-judo-chop look you give the contractor when he slaps you with an unfair change order.