Understanding Plinth Area in Building Construction

This civil engineering article briefly explains the plinth, plinth area, plinth level, plinth height etc.

1. Plinth: Plinth is built up over the ground level.

It is defined as the ground floor of the building. According to building bye law, plinth always remains over the ground level or road level.

Plinth is the border which separates the substructure and superstructure. Simply, the Plinth belongs to the bottom section of superstructure and located upper from the ground level.

2. Plinth Level: The level at which Substructure is ceased and superstructure is started known as Plinth level. It is the section of the superstructure among natural ground level and Finished floor level.

3. Plinth height: The plinth height is captured from the natural level or ground level or road level to plinth level. Plinth level stops surface water penetration into the building. It safeguards the superstructure against dampness or moisture. Plinth height resists overflowing drainage from ingressing the building.

Note: The plinth height should remain among 300 - 450 mm from ground level. It is suggested to retain minimum plinth height 150 mm from natural level.

Note: To determine the plinth Area, the exterior wall of floor should be calculated perfectly.

The followings should be included in the plinth Area:

Also Read: Construction Process Of Plinth Beam

a) Area of each Wall.
b) The wall that is common regarding two building, half area of that wall should be considered in measuring plinth area.
c) If there is open Veranda with parapet that is safeguarded with the projections then all the areas (Parapet wall + wall from top side + grills) should be included.
d) Staircase room specifically Head Room should also be taken into consideration.
e) If the Balconies which is safeguarded with the projections, then all the areas (i.e Parapet wall + wall from top side + grills) should be considered.

f) Only 50% area should be considered for exposed balconies by projections.
g) Plinth area = Carpet area + wall thickness
h) Cost of the plinth area = plinth area (sq. meter) x Rate of cost in per sq. m.

The following areas should be excluded from the calculation of the Plinth Area:

1. Terrace Area
2. Open staircase
3. Loft area
4. Lift room

5. Entrance Porch is included.