Sill is the base of the window i.e. the level from the floor of the room from which window starts (moving upwards).The window finishes at the top at the lintel level. A window sill may be equal to or greater than the width of the brickwork beneath it.

Difference Between Plinth Level, Sill Level, and Lintel Level.

Types of Level in the Building as Below

Table of Contents

- - Ground Leval / Floor Level
  - Natural Ground Level
  - Floor Finishing Level
  - Existing Ground Level
  - Plinth Level
  - Sill Level
  - Lintel Level

What Is Ground-Level / Floor Level?

- G.L. full name is Ground Level. F.L. full name is Floor Level.
- The term ‘Ground Floor’ or ‘Ground Level’ is used to refer to this level of a building that is at street/ground level.
- The term ‘story’ tends to refer to all levels of a building above the Ground Level / Floor Level.
- It can also refer to this level of ground that hasn’t be built on.
- This level of the ground before any excavation or filling has been carried out is referred to as the ‘Natural Ground Level,’ whereas ‘Finished Ground Level’ is when it has been ‘Finished’ with paving stones, asphalt, landscaped grass, and so on.

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What Is Natural Ground-Level?

- N.G.L. full name is Natural Ground Level.
- The natural ground level is termed as the level of the ground.
- The height of Natural ground level (NGL) is generally measured with the Mean-sea level.
- A natural ground level is what “mother earth” has provided us, and an existing ground level may be either cut or filled and, therefore, a different elevation than the original natural ground level.

Plinth Level

What Is Floor Finishing Level?

- F.F.L. full name is Floor Finishing Level.
- The ground level inside the building is knowns Floor Finish level.
- This level is at the height of a minimum 150mm – 450mm from the Natural ground level (N.G.L).
- The reason for raising building height is to restrict the entry of water during storms and rainfall.
- The height may go up to meters if the building located in slope and heavy rainfall areas.
- Natural assume of F.F.L near about 100.oo m R.L.

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What Is Existing Ground Level?

- E.G.L. full name of Existing Ground Level
- After earth filling of above natural ground level that above the level surface, this surface area called the existing ground level.
- E.G.L. normally after filling soil compaction.

What Is Plinth Level?

- The plinth is the part of the superstructure between the top of the tie beam at the finished ground level (the top level of the soil surrounding the structure that has been prepared and leveled before construction) and the floor level of the building( the ground floor level inside the building).
- The plinth height is provided essentially to protect the superstructure from dampness, which may seep in due to direct contact from the ground. The top plinth level is provided with the damp proof course, which is additional protection against dampness.
- This is the portion of structure between the surface of the surrounding ground and surface of the floor, immediately above the ground.
- As per Byelaws, the plinth should not be less than 45cm. The basic requirements of plinth area
  - To transmit this load of the superstructure to the foundation
  - To act as a retaining wall to keep the filling portion below the raised floor or the building
  - To protect the building from damp or moisture penetration into it
  - It enhances the architectural appearance of the building

Sill level

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What Is Sill Level?

- Sill is the base of the window i.e. the level from the floor of the room from which window starts (moving upwards).
- The window finishes at the top at the lintel level. A window sill may be equal to or greater than the width of the brickwork beneath it.
- This level between the base portion of the window and portion of the floor above ground level (upwards) is called the Sill level. A mortar bed or concrete bed is laid at the base of the window.
- The height of the sill level depends upon the type of room for bedroom & bathroom the height.

What Is Lintel Level?

- The level between the top portion of the window and the top slab is called the Lintel level.
- The lintel is provided above the door and window to transfer the upward wall load to the surrounding wall.
- The lintel is generally made up of Reinforced concrete or cement mortar.
- The actual frame of the door or window is not strong enough to support the weight of the wall above the strong enough to support the weight of the wall above the openings, and a separate structural element has, therefore, to be introduced. This is known as a lintel. This lintel area level also is known lintel level.

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Difference Between Plinth Level, Sill Level, and Lintel Level.

Sr.No.	Plinth Level	Sill Level	Lintel Level
1	The plinth is the part of the superstructure between the top of the tie beam at the finished ground level	Sill level is the part of window . Window sill are provided between the bottom of window frame and wall below	Lintel beam the actual frame of door or window is not strong enough to support the weight of the wall above the opening and separate structural element has, therefore to be introduced. this known as lintel and similar to a beam
2	This level of below the floor fishing . This level constructed beam that beam called Tie beam.	This level between the base portion of the window and portion of the floor above ground level (upwards) is called the Sill level. A mortar bed or concrete bed is laid at the base of the window.	The level between the top portion of the window and the top slab is called the Lintel level.
3	The plinth is generally made up of Reinforced concrete or cement mortar.	The sill is generally made up of Reinforced concrete or cement mortar.	The lintel is generally made up of Reinforced concrete or cement mortar.