Mortar between masonry units consists of cement, lime, and sand. These materials are used in different mix proportions. For example, a lower strength mortar of this type would have a proportion 1:2:9 cement:lime:sand, and a higher strength mortar would have proportions of 1:1/2:3 1/2 cement:lime:sand. This mortar has a similar colour as cement:sand mortar. Lime is usually added to improve workability at the time of construction, but it does not improve strength.

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)

All types of clay tile and concrete tile roofing. Overlapping and sometimes fastened to wood battens. Also includes flat roofs that are covered with paving tiles (laid over some type of membrane), but does not include stone slabs.


Clay tiles, Cuba (S. Brzev)


Clay tile roof covering, Padang, Indonesia (J. Bothara)


Clay tiles (Mangalore tiles), India (People in Centre)

A venue for performance and viewing of films, including music and dance performances.

Stacked earthen construction that uses clay-based soil in the form of a cohesive paste. The material is first kneaded and then shaped into large balls, which are either stacked (piled) on top of one another or thrown forcefully onto the wall. A layer is left to dry before adding the next layer to build up walls. It is not rammed after placement, as with Rammed Earth. It is possible to build very thick walls (thickness varies from 40 to 200 cm) using this technique. The earthen mixture may contain fibres, usually straw, grass, or twigs, but that is not an universal practice. Straw is often used as an additive for cob wall construction in Europe.


A cob wall under construction, India (People in Centre)


Cob building under construction, India (People in Centre)


Cob building, India (People in Centre)