Plinth Area: Meaning & Calculation

What Is Plinth Area?

The total area of the building including interior and exterior wall, measured at floor level of the basement or at any story including balconies, is defined as Plinth Area. The Plinth Area in simple words can be defined as the total area from external wall to external wall instead of internal wall to the internal wall.

If the measured area is from internal wall to internal wall then it is called a Carpet Area. Besides this, in other construction terms, the plinth area can also be referred to as the column pad area, hence it becomes important to clarify before assuming anything.

However, as discussed earlier the plinth area is also referred to as the total area covered by the house along with the interior or exterior wall.  It is normally greater by 10 to 20 % of carpet area, which includes the exclusion of walls and other components.

Read More: What Is Plinth | What Is a Plinth Beam | What is Height of Plinth

Plinth Area Meaning

The Plinth Area is a Covered Built-Up Area covered by the house with inside and outside walls. It is mostly 25-30% more compare to the carpet area. Sometimes Plinth Area is also known as Built-Up Area.

The Plinth Area of the house is calculated at the house floor level of any story or at the house floor level of the building basement. Formula wise it is calculated as the sum of the Carpet Area of the building, area of the balcony, and areas of the walls.

It is mandatory to calculate the plinth area length of a building to be 1-inch adjacent if the unit of measurement used is in feet.

Calculation of Plinth Area provides the constructor vital information regarding the cost of the building. Hence it is important to know the Plinth Area of the building.

Plinth Area Definition

The area of the house with considering inside and outside wall into count at plinth level is called Plinth area.

What Is Iclucdes In Plinth Area

While measuring the plinth area following area must be considered,

• The whole area of wall at house floor level excluding any area which is having offset from plinth of house.
• In case of building columns are projected outside of cladding work, plinth area is considered up to outer face of cladding work.
• If cladding is mad of corrugated sheet, its external edge is considered for calculation of plinth area.
• While calculating plinth area the air condition and lift, sanitary, telecomunication, electrical, water supply fittings shafts area considered.
• Stair area: 100% area is considered which is procted by roof and 50% area which is unprocted by roof
• 100% of area balcony which is cover by slab abd 50% of area which open or uncover by slab.

For alcove is made beyond the slab by using a cantilever,

• Only take into account 25% of area alcove of 1 m height.
• Only take into account 50% of area alcove of 1 m to 2 m height.
• Consider 100 % area of alcove for height more than 2 m.

What Is Not Included In Plinth Area

The following area is not counted in the plinth area calculation,

• Loft area is not considered in plinth area
• Cornice and structural band
• Sun breaker area and louvre box area project out from wall
• Slab projection of flower pots placing
• Planform which is open
• Terrace area
• Service staircase and open spiral staircase area
• The machine room area
• Dome projecting above terrace

Capet Area

The carpet area is the floor area of the usable room in the house.

Rentable Area

The floor area for which rent can be calculated. Which can be within or outside of the floor area used by the tenant.

For example office building, the area of stairway, corridor, and atrium is not directly included by it is calculated while fixing the rent of area.

Balcony Area

Any horizontal projection with balustrade or parapet to be used for sitting outside and passage for movement is considered in the balcony area.

Mezzanine Floor

The floor has a minimum height of 2.2 m and given permanent access is calculated as a mezzanine floor area.

Stair Cover Area

The area of stair which is covered by the slab or projection only to serve as protecting purpose from weathering effect and not used by habitant is called stair cover area.

Loft Area

A structure which is provided in between two floors only to serve as the purpose of storage without having permanent access to with height less than 2 m from floor level.

Porch Area

It is slab covered area provided outside of the plinth area only for vehicular movement and pedestrian access to the building.

Difference between Plinth area and Carpet area

Sr No.	Carpet Area	Plinth area
	The area of plinth excluding the area of walls and which is available for use is called carpet area.	The area at floor level including the area of walls is called the plinth area.
	It is calculated in to in without considering the area of walls.	It is measured out to out of wall construction at plinth level.
	It is a total covered area of building at floor level.	The actual area where is available for use or carpet can be stretched on it.
	It is less than 15 to 20 % compare to the plinth area	It thumps rule is that it is 15 to 20% more than the carpet area.
	In carpet area is included	In the plinth area balcony is not counted

What Are Plinth Area Rate?

The following table shows the rate for the plinth area,

Sr. No.	Description	Office/ School/ Collage	Hospital Building	Residential Buildings
1	RCC Frame Structure ( up 6 Floors)
	Floor Height = 3.60 m	25,500 Rs./sqft	26,800 Rs./sqft
	Floor Height = 2.90 m			19,500 Rs./sqft
2	Load Bearing Structures
	Floor Height = 3.60 m	21,700 Rs./sqft	22,800 Rs./sqft
	Floor Height = 2.90 m			16,600 Rs./sqft
3	Extra Floor
	Extra Floor ( up 6 to 12 stories)	580 Rs./sqft	580 Rs./sqft	580 Rs./sqft
4	Resisting Earthquake force structure	1280 Rs./sqft	1280 Rs./sqft	800 Rs./sqft
5	Basement Floor
	Floor Height up to 3.35 m	3000 Rs./sqft	3000 Rs./sqft	3000 Rs./sqft
6	Fire Safety Installation
	With riser System	800 Rs./sqft	800 Rs./sqft	800 Rs./sqft
	With wet riser and sprinkler system	1200 Rs./sqft	1200 Rs./sqft	1200 Rs./sqft
7	Fire Alarm System	250 Rs./sqft	250 Rs./sqft	250 Rs./sqft
8	Automatic Fire Alarm System	600 Rs./sqft	600 Rs./sqft	600 Rs./sqft

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