Area Measurement Comparison — All Four Types
| Area Type | What It Measures | Relative Size | Primary Use |
|---|---|---|---|
| Carpet Area | Net usable floor space between inner walls — excludes walls, balcony, common areas | Smallest — base 100% | RERA pricing (mandatory), actual living space |
| Built-Up Area | Carpet area + wall thickness + exclusive balcony/terrace | ~110–115% | Older deeds, municipal records |
| Plinth Area | Total floor area at plinth/ground level including all walls — measured at building base | ~115–120% | Government assessment, PWD costing, construction estimation |
| Super Built-Up Area | Built-up area + proportionate share of all common areas | ~125–145% | Pre-RERA builder pricing |
Where Plinth Area Is Used
Plinth area is primarily relevant in government and construction contexts — not so much in residential property buying and selling since RERA standardised pricing on carpet area. Key uses:
Where Plinth Area Is Still Used
- PWD construction costing: Government projects use plinth area for construction cost estimation — "plinth area rate" is the cost per sq ft of construction
- Municipal property assessment: Some older municipal assessment systems use plinth area for property tax calculation
- Building plan approval: Submitted plans may reference plinth area as part of technical specifications
- Valuation reports: Some bank and government valuers include plinth area in property valuation reports
- Floor Space Index calculation: FSI is computed on plinth area in some contexts
Related Terms
Frequently Asked Questions
Plinth area is the built-up area measured at plinth level (the base of the building) including all walls — internal and external — but excluding open terraces and courtyards above plinth level. It is primarily used by government bodies, PWD, and for construction costing. For residential property buying and selling, carpet area (mandated by RERA) is the relevant measure.
Carpet area is the net usable floor space between the inner walls of a flat — excludes wall thickness, balcony, and common areas. Plinth area includes all wall thickness (internal and external) measured at the building's base level. Plinth area is larger than carpet area. For modern residential transactions, RERA mandates pricing on carpet area — plinth area is primarily a technical/government measurement.
Built-up area = carpet area + wall thickness + exclusive balcony/terrace. Plinth area = area at the ground/plinth level including all walls — primarily measured for government and construction purposes. Both include wall thickness, but plinth area is specifically measured at the plinth level and excludes upper-floor open areas. In practice they are similar but plinth area has a more specific technical definition.
Not for modern residential property transactions. Since RERA 2016, residential property must be priced on carpet area. Plinth area is used for government construction cost estimation, older municipal property tax assessment, building plan approval documents, and valuers' technical reports. If a seller quotes price on plinth area, convert to carpet area before comparing with other properties.
Plinth area rate is the construction cost per square foot of plinth area — used by PWD (Public Works Department) and government agencies to estimate construction project costs. For example, a PWD residential unit at ₹2,000 per sq ft plinth area rate for 1,000 sq ft plinth area = ₹20 lakh construction cost. This is separate from land cost and is a technical construction term.