# Define "Major" Structural Modifications



## Francis Vineyard (Feb 5, 2018)

Would it be equivalent to substantial alterations in reference to the IEBC or is it defined elsewhere?
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Stairs and escalators in existing buildings.*
In alterations, change of occupancy or additions where an escalator or stair is added where none existed previously and major structural modifications are necessary for installation, an accessible route shall be provided between the levels served by the escalator or stairs in accordance with Sections 1104.4 and 1104.5 of the International Building Code.

* 907.4.2 Substantial structural alteration. *Where more than 30 percent of the total floor and roof areas of the building or structure have been or are proposed to be involved in structural alteration within a five-year period, the evaluation and analysis shall demonstrate that the altered building or structure complies with the International Building Code for wind loading and with reduced IBC-level seismic forces. The areas to be counted toward the 30 percent shall be those areas tributary to the vertical  load-carrying components, such as joists, beams, columns, walls and other structural components that have been or will be removed, added or altered, as well as areas such as mezzanines, penthouses, roof structures and in-filled courts and shafts.
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 907.4.3 Limited structural alteration. *Where the work does not involve a substantial structural alteration, the existing elements of the lateral load-resisting system shall comply with Section 807.5.


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## steveray (Feb 5, 2018)

201.3 Terms defined in other codes. Where terms are not
defined in this code and are defined in the International
Energy Conservation Code, International Fuel Gas Code,
International Fire Code, International Mechanical Code or
International Plumbing Code, such terms shall have the
meanings ascribed to them as in those codes.

Funny it doesn't mention IEBC......But I would say yes...


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