The column is an important part of any building. The entire building stands on the support of the column, and the column transfers the weight of the entire building to the footing inside the ground. Since the whole weight of the building rests on the column, it is important to know that **what is the column size for 1, 2, 3, 4, and 5 Storey buildings**.

## What is the column

The structure of any building supports the entire building and becomes a medium for transferring the weight of the entire building to the ground through the footing, that is the column. Nowadays columns are generally made of concrete. But in ancient times, the column was made by cutting stones or strong wood was also used for the column.

The column is the most important structure for any building. That’s why the size of the column is different for different-storey buildings. Special-grade concrete is used to construct the column.

### What is the column Size?

The **size of the column** is not determined beforehand. The size of the column depends on many factors like the load to be given on the column, the grade of concrete, the distance between one column to another column, etc.

As we know that the size of the column is determined by the given load on the column. Therefore, for a 2, 3, or 4-storey building, different size columns will be required. Nowadays RCC columns are used in every construction. Because the cost of the RCC column is less, and according to its cost, the RCC column has more load-carrying capacity than any other type of column.

**The standard size of column**

Before knowing the standard size of the column, there is one more important thing that we should know. Columns should always be constructed of RCC concrete.

The size of the column for the ground floor, or first-floor building, should be at least 9×9 inches, In Which 4 steel bars of Fe 500 and T8@6 stirrups should be used. M20-grade concrete should be used for the construction of columns because only M20-grade concrete is considered the standard concrete for the column.

### Some important point notice during column design

- The size of the column is determined on the basis of the load given on it.
- Large spans affect the bending of the beam. Along with the beam, spans of large size also affect the column.
- The standard size of the column works according to the thumb rule only for small-scale construction like G+1, G+2, and G+3. Because large-size constructions involve many factors. Therefore, the thumb rule for column size does not work in large-size constructions.
- The size of the column is also determined by the distance between the two columns, and the span of the beam.
- The design of columns for building construction depends on many things, like the size of the building, type of land, number of floors in the house, etc.

The design of the column should be determined based on the load to be placed on the structure. But there are some things, which we should remember during the construction of any building so that we do not make any mistakes. So we will now learn about the thumb rule to be followed while giving the layout of the column.

There are 3 main thumb rules used for the design of columns, which are as follows.

- Distance between column
- Loading condition
- Number of Floors

**1. Distance between columns:** The distance between the centre of one column to the centre of another column should be at least 3 metres and a maximum of 5 metres. As per standard code provisions if you want to increase the distance between column to column, then you have to increase the size of the column as well.

**2. Loading condition:** In column design, the most important design determining factor is the load of the building itself. The size of the column is proportional to the weight of the building. Therefore, when the load of the building increases, the size of the column also has to be increased.

**3. Number of floors**: The size of the column is proportional to the number of storeys, and when the number of storeys in the building increases, the size of the column also has to be increased.

**The minimum size of the RCC Column**

The standard size of any RCC column should be at least 9 × 9 inches or 228 × 228 mm. In Which 4 pieces of 12 mm Fe 500 steel bar and T8@6″C/C should be fixed with stirrups, and concrete of M20 grade should be used.

### Column Size for 1st-floor building/ ground floor

As per the thumb rule, the standard column size 9 × 9 inches (228mm × 228mm) is perfect size for buildings up to the first floor/ ground floor. For column size of first floor buildings M20 grade concrete, 4 piece Fe 12mm steel bar whose grade should be Fe500 and T8@6″C/C stirrups used.

### Column size for 2 storey (G+1) Building

**Standard column size for 2 storey building**

As per the thumb rule, the standard column size for 2-storey building is 9 × 12 inches (228mm × 300mm) and this is the perfect size for buildings up to the 2 floor/ G+1 floor. For column size of 2-storey buildings M20 grade concrete, 6 pieces 12mm steel bar whose grade should be Fe500 and T8@6″C/C stirrups used.

### Column size for 3 storey (G+2) Building

As per the thumb rule, the standard column size 12 × 12 inches (300mm × 300mm) is the perfect size for buildings up to the 3 floor/ G+2 floor. For column size of 3-storey buildings M20 grade concrete, 6 pieces 12mm Fe500 steel bar with T8@6″C/C stirrups has used.

### Column size for 4 storey building (G+3) Building

As per the thumb rule, the standard column size 12 × 15 inches (300mm × 380mm) is the perfect size for buildings up to the 4 floor/ G+3 floor. For columns of 4-storey buildings M20 grade concrete, 4 pieces 16mm and 2 pieces 12mm steel bar whose grade should be Fe500 and T8@6″C/C stirrups used.

### Column size for 5 storey building (G+4) Building

As per the thumb rule, the standard column size 12 × 18 inches (300mm × 450mm) is the perfect size for buildings up to the 5 floor/ G+4 floor. For column of 5-storey buildings M20 grade concrete, 4 pieces 16mm and 4 pieces 12 mm steel bar whose grade should be Fe500 and T8@6″ C/C stirrups used.

### Column size chart for Different storey Building

The size of the column is determined according to the floor of the building. Because the more floors there are in any building, the more load will increase on the columns of that building. Therefore, as the number of floors in the building increases, the size of the column also increases.

Building Floor | Column size in mm | Column size in inches |
---|---|---|

Ground | 230 mm × 230 mm | 9″ × 9″ |

G+1 | 230 mm × 300mm | 9″ × 12″ |

G+2 | 300 mm × 300mm | 12″ × 12″ |

G+3 | 300 mm × 380 mm | 12″ × 15″ |

G+4 | 300 mm × 450 mm | 12″ × 18″ |

G+5 | 380 mm × 450 mm | 15″ × 18″ |

G+6 | 450 mm × 450 mm | 18″ × 18″ |

G+7 | 530 mm × 530 mm | 21″ × 21″ |

G+8 | 600 mm × 600 mm | 24″ × 24″ |

G+9 | 700 mm × 700 mm | 28″ × 28″ |

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#### Conclusion:

In this article, we have discussed what should be the column size of different-storey buildings. And in this article, we have also discussed which factor decides the column size. I hope I have answered all the questions related to column size.

##### FAQ

**What is the standard size of the column for single-storey building?**

The best standard size of column for a single-storey building is 9” × 9”. Which should be made of M20 concrete.

**What should be the size of the column for building?**

I suggest at least 9″×12″ size column for the building.

**Size of column for 2 storey building**

For 2 storey building 9″×12″ column size is the standard size, and this size is according to the IS code.

**Column size for G+1 building in mm**

For G+1 building the column size in mm is 230 mm × 300mm, and this size is according to IS code.

**What should be the Column size for 3 storey building**

For 2 storey building 12″×12″ column size is the standard size, and this size is suggested by the IS code.

**Column size for residential building**

If you plan to construct a residential building, the column size should be at least 9” × 9”.