Changes in vertical structure when the structural system and/or structural material changes up the height of the building. This also covers the irregularity referred to as "Offset Structure" in some building codes. The Offset Structure refers to a case when the lateral load-resisting system is not vertically continuous from foundation to roof, but has a horizontal offset somewhere up its height. These buildings may have two different lateral load-resisting systems at some floor levels, but not across all levels (vertically), or across the entire plan (horizontally).

Change in vertical structure (FEMA 2006)

Change in vertical structure (FEMA 454, 2006)

Out-of-plane offset: discontinuous shear walls (FEMA 2006)

Offset structure - discontinuous shear walls (FEMA 454, 2006)


Transamerica Pyramid, the tallest skyscraper in San Francisco, California is characterized by a change in vertical structure (S. Brzev)


Change in vertical structure, Seattle, USA (S. Brzev)


Change in vertical structure, a temple in China (D. Willms)


This building in Rawalpindi, Pakistan is characterized by a change in vertical structure and it suffered damage in the 2005 Kashmir earthquake (C. Scawthorn)


A Kasbah in Tanger, Morocco with a large overhang (C. Scawthorn)


Change in vertical structure, Seattle Central Library, USA (S. Brzev)


A building with large overhangs, University of California Berkeley, USA (S. Brzev)


This building in India has large overhangs (People in Centre)