Topic Title

Part of an existing building is three stories, the remainder is two stories. If a third story is added to the two story portion is it an "addition" per IEBC?

It is an extension and increase in floor area. However, it does not increase the floor area per story which applies to Table 501, does not increase the height, or the number of stories.

Any suggestions based on past experiences?

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SECTION 202 GENERAL DEFINITIONS

ADDITION. An extension or increase in floor area, number of stories, or height of a building or structure.

Also need to verify you still comply with 506.4 for "Total Building Area", which shouldn't be an issue.