You can measure a small land for construction with the help of measuring tape, but the same methodology can’t be applied to investigate a large area.

Surveying is one of the fundamental subjects which helps you to kick start any project. Even though the result of surveying supports the execution of the project, we can quickly identify the hindrances at the earliest. 

birds eye view of land

The result of surveying is like a syllabus of a course that will guide whether a topic needs to be covered before starting another. The Survey will guide us through the project whether a work has to be completed before starting another.

Let us discuss the principle of surveying along with its importance in construction.

What is surveying in civil engineering?

Surveying is the branch of civil engineering to discover the comparable position of peculiar features of the earth’s surface by measuring the distance, directions & elevations of the earth.

Importance of surveying in civil engineering

The surveying is the crucial initial step (plan) of a project execution which helps to manipulate the project without errors. Once the plan is set out accurately, then there is no need to spend more time to re-evaluate the land. Some basic importance of surveying is listed below. Principles of Surveying

  • A survey can determine the required land acquisition. 
  • To prepare the route map of the pipeline or road project.
  • The surveying also prepares the military map & normal land map.
  • The result of surveying prepares the topographical & hydrographic maps.
  • The survey map contains the undulation of the earth surface, obstruction, river & hills positions, etc.,
  • The boundary lines of the earth’s surface are marked by using the surveying, which is helpful to ensure the project does not execute in another land.
  • The level of filling & cutting of earth surface for any project like road construction, the bridge has been determined & fixed by the points of surveying. 

What is the main objective of surveying?

The main objective of surveying is to show all the features of the earth’s surface (larger area) prepared as a plan or map in a horizontal plane. 

The scale of the area describes the difference between the plan & map. If the range represents a small area, then it is called a map at the same time if the scale denotes a more substantial space that is called a plan. 

For example, Map of the world & Plan of a building. 

map and plan

Principles of surveying

The main principle of surveying is,

  • To work from whole to the part
  • Locating new points by measurement of minimum two reference points

Working from the whole to the part

The main principle of this method is establishing the survey work from the whole to the part. 

For example, if you are going to take surveys for vast land first, you have to fix systematic control points with high precision around the area—a boundary line formed by connecting the points which are the main skeleton drawing of the survey.

Working from the whole to the part
The survey points are established by triangulation or traverse around the area. Then the triangles are broken into small areas and can be measured by less workmanship. 

The primary purpose of work from the whole to the part survey is to avoid the error. In case the survey works are established by part to whole, then we have to face many mistakes in the surveying.

Locating new points by measurement of minimum two reference points

Two different independent processes have to do to fix a new point. The two different methods can cross-check together.

locating new points


From the above picture, C is new, which has to be fixed & point A, B are the given point. 

  • Now the point C can be fixed by measuring the distance of AC & BC; it is one method of process.
  • A perpendicular line may be drawn from point C to baseline AB. Now we have got two different possibilities to locate point C by the line CD.

In the upcoming post, we will discuss the types of surveying methods.

Happy Learning 🙂


Satheesh is a Civil Engineer who has more than 9+ Years of experience in residential construction. He is the author, editor of Civil Planets

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