For alterations of existing buildings, the building owner has the option to use the 1968 building code or earlier depending on the original construction date of the building. There are exceptions to this for certain worktypes and trades.
Typically all Mechanical, Plumbing, Fire Protection, Structural, and Accessibility related work will need to comply with the 2014 while general construction and architectural work may utilize the older code as applicable.
Keep your workers posted before they miss their deadline.
What you need to know when Local Laws 92 & 94 go into effect.