PAGER - Common Building Types
Brick masonry with timber frame
This type of house is used for residential purposes. The building type under study has been picked the from central part of India (state of Madhya Pradesh), but it is found throughout India with small or large variations. Timber is primarily used for the frame structural elements but due to an acute shortage of timber, this construction type is not practiced anymore. Various components of the building change from place to place depending on climate, socio-economic conditions, availability of material, etc. Timber frames, placed in longitudinal and traverse directions, are filled with brick masonry walls. The floor structure is made of timber planks. Most of the buildings are found to be rectangular in shape with few openings. The roofing material is usually light when it is made from galvanized iron sheets. Seismic performance of a perfectly framed building is very satisfactory. Existing old structures, however, require maintenance and strengthening. It has been observed that nominal cost will be incurred for introducing earthquake resistant features.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #116) - Amit Kumar, Jeewan Pundit
Timber frame construction
The housing type is most common throughout Northeast India, which lies in the most severe seismic zone of the country (Zone V - corresponding to MSK IX). The majority of this type of building are used for residential purposes. Typically these houses are built with light weight, locally available material like bamboo, wooden planks, thatch etc. These housing types have the traditional system of bamboo/wooden posts. Bamboo posts are inserted into the ground to act as compression members and are tied with horizontal bamboo/wooden girders with the help of bamboo ropes (cane) to give a proper shape and framing action. However, there is no protection of bamboo/wooden posts against decaying/termites or any other natural cause. The performance of these houses during past earthquakes is unknown. However, during discussions with local people about the performance of these houses in the past major earthquakes, it was noted that the majority of houses survived.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #147) - Amir Ali Khan
Elevated timber/log construction (Koti Banal Architecture)
This distinct construction type known as Koti Banal, derived from the name of a village in the Yamuna Valley in Northern India, represents the traditional knowledge and understanding of earthquake effects on buildings and their earthquake resistant design. Koti Banal architecture makes use of locally available building materials such as long, thick wooden logs, stones, and slates. The height of these structures varies between 7 and 12 m above the base platform (usually four to five stories) which consists of dry stones. The buildings are further characterized by a number of advantageous design features such as regular plan shapes, the sensible use of locally available building materials, the integration of wooden beams over the total height of the building, small openings, and the arrangement of shear walls. The media and other sources indicate that the Koti Banal architecture withstood and performed well during many past damaging earthquakes in the region.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #150) - Piyoosh Rautela, Girish Chandra Joshi, Yogendra Singh, Dominik Lang
Rubble stone masonry walls with timber frame and roof
This typical rural construction in central, southern, and northern India houses millions of people. It is cheap to construct using field stones and boulders, but extremely vulnerable in earthquakes because of its heavy roofs and poorly constructed walls. The load-bearing structure is a traditional timber frame system, known as 'khann'. It is a complete frame with timber posts spanned at about 2.6 m. Thick stone walls (typical thickness 600 mm - 1.2 m) provide enclosure and partial support to the roof. Walls are either supported by strip footings of uncoursed rubble masonry or are without any footings at all. The roof structure consists of timber planks and joists. To help keep the interiors cooler during hot summer months (peak temperatures exceeding 40°C.), a 500-800 mm thick mud overlay covers the top the roof. This construction type is considered to be very vulnerable to earthquake effects.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #18) - Svetlana N. Brzev, Marjorie Greene, Ravi Sinha
Reinforced concrete frame with masonry infill walls designed for gravity loads
The construction of reinforced concrete buildings with brick masonry infill walls has been a very common practice in urban India for the last 25 years. Most of this construction has been designed for gravity loads only, in violation of the Code of Indian Standards for earthquake-resistant design. These buildings performed very poorly during the Bhuj earthquake of January 2001 and several thousand buildings collapsed. The collapse was not limited to the epicentral region. The seismic vulnerability of this construction is clearly demonstrated by the collapse of about 75 reinforced concrete frame buildings and damage to several thousand others in and around Ahmedabad, which is over 250 km from the epicenter.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #19) - Kishor S. Jaiswal, Ravi Sinha, Alok Goyal
Unreinforced brick masonry walls in mud mortar with flat timber roof
This is a traditional construction practice prevalent both in the urban and rural areas of northern India, particularly in the western part of the Uttar Pardesh state. According to the 1991 Indian census, this construction constitutes about 17% of the total national housing stock and about 31% of the state of Uttar Pradesh housing stock. Typically, this is a single-story construction. The main load-bearing elements are unreinforced brick masonry walls in mud mortar built without any seismic provisions. The roof structure consists of timber beams supported by the walls. Clay tiles or bricks are laid atop the beams; finally, mud overlay is placed on top of the tiles for the thermal protection and to prevent leakage. The main seismic deficiencies are heavy roofs and low-strength masonry walls, which render the building rather vulnerable to seismic effects.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #20) - Amir Ali Khan, Khalid Moin
Unreinforced brick masonry building with reinforced concrete roof slab
This is typical rural and urban construction in western and southern India. This construction is widely prevalent among the middle-class population in urban areas and has become popular in rural areas in the last 30 years. Brick masonry walls in cement mortar function as the main load-bearing element. The roof structure is a cast-in-situ reinforced concrete slab. If constructed without seismic features, buildings of this type are vulnerable to earthquake effects. They exhibited rather poor performance during the Koyna (1967), Killari (1993), Jabalpur (1997), and Bhuj (2001) earthquakes in India.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #21) - Ravi Sinha, Svetlana N. Brzev
Unreinforced brick masonry walls with pitched clay tile roof
This is a traditional construction practice followed in India for centuries. Buildings of this construction type are used for residential, commercial, and public purposes throughout India, especially in the northern and central parts, where good quality soil for brick production is widely available. This is a single-story construction used both in rural and urban areas. The walls are constructed using clay bricks laid in mud, brick-lime or cement/sand mortar. The roof does not behave as a rigid diaphragm. These buildings are built without any seismic provisions and are considered to be moderately-to-highly vulnerable to earthquake effects.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #22) - Amit Kumar
Rural mud house with pitched roof
This is a typical rural construction found throughout India, except in the high rainfall areas in the northeastern part of the country. The main load-bearing system consists of mud walls, which carry the roof load. In some cases wooden posts are provided at the wall corners and at intermediate locations. The wooden posts and walls are not structurally integrated, and therefore the loads are shared by the walls and the frame. There are very few openings (doors and windows) in these buildings. In rural areas there are usually no windows at all. In general, this type of construction is built by the owners and local unskilled masons and the craftsmanship is very poor. This building type is classified as grade-A (most vulnerable) per the IAEE building classification and IS Code 1893:1984. This is a low-strength masonry construction and it is considered extremely vulnerable to seismic forces.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #23) - Amit Kumar
Traditional rural house ("Bhonga")
The Bhonga is a traditional construction type in the Kutch district of the Gujarat state in India, which has a very high earthquake risk. A Bhonga consists of a single cylindrically shaped room. The Bhonga has a conical roof supported by cylindrical walls. Bhonga construction has existed for several hundred years. This type of house is quite durable and appropriate for prevalent desert conditions. Due to its robustness against natural hazards as well as its pleasant aesthetics, this housing is also known as "Architecture without Architects." It performed very well in the recent M7.6 Bhuj earthquake in 2001. Very few Bhongas experienced significant damage in the epicentral region, and the damage that did occur can be mainly attributed to poor quality of the construction materials or improper maintenance of the structure. It has also been observed that the failure of Bhongas in the last earthquake caused very few injuries to the occupants due to the type of collapse.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #72) - Madhusudan Choudhary, Kishor S. Jaiswal, Ravi Sinha
Low-strength dressed stone masonry
Stone masonry buildings are common in both urban and rural parts of India. In rural areas, stone masonry buildings are single-story, single-family dwelling. In urban areas, these buildings are up to four stories high and are used for multifamily housing. This is a typical load-bearing construction, in which both gravity and lateral loads are resisted by the walls supported by strip footing. Mud or lime mortar has been used in traditional constructions; however, more recently, cement mortar is being increasingly used. These houses are usually built by local artisans without formal training and the resulting constructions are structurally weak and incapable of resisting large seismic forces. Roofing consists of a gable end timber roof truss or RC slabs. Thousands of these houses collapsed in the 2001 Bhuj earthquake resulting in the deaths of large numbers of people. This construction type is inherently unsuitable for areas of moderate-to-high seismic hazard.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #80) - Ravi Sinha, Vijaya R. Ambati
*Building types and their descriptions are taken from the World Housing Encyclopedia (WHE) database when available or based on additional research performed by the PAGER team. This information is provided with the understanding that it is not guaranteed to be correct or complete, and conclusions drawn from such information are the sole responsibility of the user.