Legal Definitions - alteration

Definition: A significant change made to a building or other structure, essentially creating a different building or structure. It can also refer to a substantial change to real estate, especially to a structure, usually not involving an addition to or removal of the exterior dimensions of a building's structural parts.

• Adding a new floor to a building is an example of a structural alteration.
• Changing the layout of a room by removing a wall is an example of a real estate alteration.
• Changing the date, time, place, amount, or rate of interest on a negotiable instrument without the consent of all parties to it is an example of an alteration that can void the instrument.

The examples illustrate that an alteration can refer to a significant change made to a building or structure, or a change made to a legal document that can affect the rights and obligations of the parties involved. In both cases, the change must be substantial and not simply a minor modification.