# How to Calculate Estimation for Building Works?

The following three methods are often wont to estimate the quantities of varied items like earthwork in excavation, foundation concrete, brickwork in foundation and plinth, brickwork within the superstructure etc.:

• Centre Line Method
• Long and short wall method
• Crossing Method

### 1. Centre Line Method

The total center line length of walls during a building is first calculated during this method of estimation. the middle line length is then multiplied with the breadth and depth of the item in question so on get the entire quantity at a time.

The center-line length for every type are going to be figured out separately for various sections of the walls within the building. just in case of verandah walls or partition joining with the most wall, there's a discount of the center-line length by half the breadth of the layer of the most wall that joins with the partition or verandah wall at an equivalent level.

Using this method, you'll estimate more quickly, this method is additionally as accurate because the remainder of the methods.

This method has no advantage over the opposite methods only within the case of unsymmetrical wall where the center-line length varies at every layer.

In case of estimating circular, hexagonal, octagonal, etc. shaped buildings, this method are often adopted.

### 2. Long and Short Wall Method

The longer walls during a building, usually in one direction, are considered as long walls and are measured from bent call at this method. For the short or partition walls during a perpendicular direction of the long walls are considered as short walls. it's measured from in-to-in for a selected layer of labor .

The length of long and short walls is multiplied individually by the breadth and height of the corresponding layer and it's added to urge the number .

In every layer of footing the lengths of long and short walls varies. it's important to work out center to center lengths individually from the decide to calculate the lengths of long and short walls.

The length of long wall, out-to-out must be calculated by adding half breadth of a wall at each end with the middle to center length.

Therefore, the length of the short wall are often acknowledged by measuring in-to-in after subtracting half breadth at each end from the middle to center length.

There is a decrease within the length of long-wall from earthwork to brickwork within the superstructure but just in case of a brief wall the length increases.

In some cases, a wall is taken into account short at one end and long at the opposite end, the rationale why such case happens is because an extended wall is joined with another long wall and later the joining end of the wall which was considered as long wall is treated as short end and thus called long-short-wall.

### 3. Crossing Method

In this method the general perimeter of the building is calculated then subtracted from the fourfold thickness of the wall to get the center-line length.

This method isn't used widely now.

First calculate the entire length of the center-line which remains constant for a varied width of works, then multiple this constant length of the center-line with the breadth and height to estimate the quantities.

Therefore, the total length of center-line = 2 [ (3m + (2 x (30 cm/2)) + (2.5m + (2 x (30 cm/2))]

Which results to the total length of center-line = 12.2 m

Example for the Long and Short wall Method

Center to Center length of long walls = 3 + (2 x 0.115) = 3.3 m

Center to Center length of long walls = 2.5 + (2 x 0.115) = 2.80 m

In every layer of footing the length of the long walls out-to-out and the short walls in-to-in vary. 