Abuilding is consists of many structural components. Generally, structural components are divided into two categories-

1. a) Sub structure and
2. b) Super structure

Sub structure:

The structure below ground level is called sub structure. Sub structure can also be divided into two parts-

1. a) Foundation and
2. b) Plinth

Foundation:

The most lower part of the building. The main function of the foundation is to transfer load to sub soil. It is the most important part of structure. Most of the failure of a structure may happen due to foundation failure. Foundation should be strong enough to meet the following requirements-

1. a) It should be strong enough to distribute the load to sub soil.
2. b) It is capable to support structure.

Super Structure:

The part above plinth level is called super structure. Super structure contains many other structural components. Such as-

1. a) Wall
2. b) Floor/Slab
3. c) Lintel and sunshade
4. d) Step and stair
5. e) Roof

Wall:

Wall is used to separate the usable area of floor for different purpose. Such as bedroom, bathroom, kitchen, living etc. Other prime purpose of wall is to provide privacy and security.

Floor:

The main purpose of floor is to provide better living space and support of occupants, furniture and other equipment of a building. The purpose of making different floor in different level of a building is to create more accommodation within limited space. Floor should be strong, durable, damp prove and heat protected.

Lintel and Sunshade:

Lintel is provided for the purpose of supporting wall above door or window opening. Sunshade is generally combined with lintel above window opening to protect rain and sun.

Step and Stair:

Stair is made for easy communication among various floors of a building. Stair consists of steps. Steps height should be comfortable enough for vertical movement.

Roof:

The top most part of a building is the roof. Roof is build for the purpose of enclosing and protect the living area/floor area from weather effect. Roof should be stable, durable and weather resistant.

There are also others structural parts of a building. Such as water tank, septic tank and parapet etc. Septic tank and underground water tank is completely separate structural part and not included in building structure. But, parapet and overhead water tank are parts of building structure.

To understand how structures work, a few basic concepts must be explained. A structure must be designed to resist the likely forces it will encounter and not fail or deflect too much. The common forces are wind load, earthquake load, dead load (the actual weight of the structure itself) and live load (people or stored materials). The building code generally sets the limits for those various design loads.

But the best place to begin an understanding of simple structural analysis isn’t in the building codes and the stipulated loads, but in knowing how simple structural elements work and fail.

To understand how structures work, a few basic concepts must be explained. A structure must be designed to resist the likely forces it will encounter and not fail or deflect too much. The common forces are snow load, wind load, earthquake load, dead load (the actual weight of the structure itself) and live load (people or stored materials). The building code generally sets the limits for those various design loads.