Land & Earthwork Resources

Plot Area vs Built-Up Area vs Carpet Area

Q: What is the difference between plot area, built-up area, and carpet area?

Plot area is the total land within the property boundary — the size of the land parcel. Built-up area is the total covered floor area of the building measured to the outer face of the external walls — it includes internal walls, balconies, stairwells, and common areas. Carpet area is the net usable floor area within the property measured to the inner face of the walls — the space where you can actually lay a carpet and place furniture. Carpet area is always smaller than built-up area, which is always smaller than plot area.

Q: Why is carpet area less than built-up area?

Carpet area is less than built-up area because built-up area includes the thickness of all external and internal walls, structural columns, covered balconies, stairwells, lift shafts, and proportionate common areas — none of which appear in the carpet area. The difference is typically 15–30% of the built-up area. For an apartment with 1,000 sq ft built-up area, the carpet area is typically 700–850 sq ft. The remaining 150–300 sq ft is wall thickness, balcony, and common area share.

Q: What is FAR and how does it affect how much I can build on my plot?

FAR (Floor Area Ratio) — called FSI (Floor Space Index) in India — is the ratio of total built-up area permitted to plot area. It is set by the local planning authority for each zone. FAR determines how intensively you can develop a plot. A plot of 300 m² with permitted FAR 2.0 allows a maximum total built-up area of 600 m² across all floors. You can achieve this as 3 floors of 200 m², or 2 floors of 300 m², or any other combination that totals 600 m². Exceeding FAR requires special approval or is unauthorised construction.

Q: What is super built-up area and how is it different from built-up area?

Super built-up area (SBUA) is an Indian real estate term that adds a proportionate share of the building's common areas (lobby, staircases, lift, security room, generator room, amenities) to the individual unit's built-up area. It is always the largest of the four area measurements. Before RERA 2016, many Indian developers sold flats on super built-up area with a loading factor of 1.25–1.40 — meaning buyers paid for 1,400 sq ft of SBUA but received only 1,000 sq ft of carpet area. RERA now requires all residential property sales in India to be based on carpet area, making SBUA irrelevant for registered projects.

Q: How do I calculate how many floors I can build on my plot?

Step 1: Apply setbacks to find the maximum building footprint — net buildable width × net buildable depth. Step 2: Check ground coverage limit — footprint ÷ plot area must not exceed the permitted percentage. Step 3: Calculate maximum total built-up area — plot area × permitted FAR. Step 4: Divide maximum BUA by footprint to get the number of floors. Example: 300 m² plot, FAR 1.75, 60% coverage, 1.5m setbacks all sides → Footprint = approximately 160 m²; Maximum BUA = 300 × 1.75 = 525 m²; Floors = 525 ÷ 160 = 3.28 → 3 full floors.

Q: Is carpet area the same in all countries?

The concept is the same globally — net usable floor area within the unit to the inner face of walls — but the terminology and exact definition vary by country. India uses Carpet Area (legally defined by RERA). The UK uses Net Internal Area (NIA) per RICS standards. The US uses Usable Area or Net Rentable Area (NRA) per BOMA standards. Australia uses Net Lettable Area (NLA) per the Property Council of Australia. The differences are in exactly what is included at the boundaries — whether internal staircase, balconies, or store rooms within the unit are included or excluded. When comparing properties across countries, confirm what the area figure includes before making a direct comparison.

Q: How do setbacks reduce the buildable area of my plot?

Setbacks are minimum distances required between the building and each plot boundary. Every setback reduces the buildable footprint of your plot. For a 12m × 18m plot with 2m front, 1.5m rear, and 1m side setbacks: buildable width = 12 − 1 − 1 = 10m; buildable depth = 18 − 2 − 1.5 = 14.5m; maximum footprint = 145 m² out of a total plot area of 216 m². The setbacks consume 33% of the plot. This is why the buildable area is always less than the plot area, and why you cannot simply multiply plot area by FAR to determine total built-up area without first checking ground coverage limits and setback dimensions.

Q: What is the difference between FAR in India (FSI) and FAR in other countries?

FAR and FSI are the same concept — the ratio of total built-up area to plot area — with different names in different markets. India uses FSI (Floor Space Index). The US and most international markets use FAR (Floor Area Ratio). Singapore uses Plot Ratio. Germany uses GFZ (Geschossflächenzahl). The numerical values are not comparable across cities without knowing local norms — an FSI of 1.75 in a Bengaluru residential area is considered standard; an FAR of 1.75 in suburban New York is considered moderate; an FAR of 1.75 in central Singapore would be very low. Always evaluate FAR or FSI in the context of local norms for the specific zone and city.

Q: How do I verify the carpet area of an apartment before buying?

In India: registered RERA projects must disclose carpet area in the allotment letter and sale agreement — request the RERA carpet area disclosure and verify it matches the project's RERA registration. In the UK: commission an RICS-measured Net Internal Area survey of the property before exchange. In the US: request the floor plan with room dimensions from the seller and measure key rooms independently. In Singapore: check the strata area in the approved building plan from BCA. Universally: calculate the sum of room dimensions from the floor plan (length × width for each room, minus wall thickness) and compare to the stated carpet area — any significant discrepancy warrants investigation.

When buying land, purchasing a flat, or planning a new building, three area measurements appear repeatedly in every document, drawing, and conversation: plot area, built-up area, and carpet area. They sound like variations of the same thing. They are not. Each measures something fundamentally different, and confusing them leads to real financial and planning consequences. A property advertised as 2,000 sq ft may have a carpet area of only 1,400 sq ft — the remaining 600 sq ft is walls, balconies, and common areas that form part of the built-up area but are not usable living space. A plot of 3,000 sq ft does not mean you can build a 3,000 sq ft house — local planning regulations (Floor Area Ratio, ground coverage limits, setbacks) restrict how much of that plot can be built on and how tall the building can be. This guide explains each term precisely — what it includes, what it excludes, how it is calculated, how the three relate to each other, and what they mean in the context of property transactions and construction planning. The concepts apply globally, with local terminology variations noted where relevant.

Last updated: June 30, 2026

Plot Area

Plot area is the total land area within the boundary of a parcel of land. It is the size of the ground itself — before any building is placed on it. Plot area is measured in plan (horizontal projection) regardless of the topography — a sloping plot has the same plot area as a flat plot of the same boundary dimensions.

Plot area is the starting number for everything else in construction planning. All other area measurements — built-up area, carpet area, ground coverage — are derived from or constrained by the plot area.

What It Includes

The full land within the legal boundary — including all areas within the compound wall or property line
Areas under the building footprint
Open areas within the plot — garden, driveway, courtyard, setback zones, open parking
Areas under the compound wall itself
Any internal road or pathway within the plot boundary

What It Excludes

Road area outside the property boundary — even if a road widens into the plot's registered dimensions
Road setback reservations — areas reserved for future road widening are often shown in title documents but are not available for construction
Areas acquired after the original registration — additional land purchases are registered separately

How Measured

Plot area is measured from the boundary marks, corner pegs, or survey stones that define the legal property. For a rectangular plot, it is simply length × width. For irregular plots, it is calculated by dividing the plot into triangles or using the Shoelace formula (Surveyor's Formula) from surveyor-measured coordinates at each corner.

The registered plot area in the title document (sale deed, title deed, land certificate) is the legal area. The measured area on the ground may differ slightly from the registered area due to accumulated survey errors over time — particularly in older properties. Where there is a discrepancy, the legal document governs for transactions; the physical measurement governs for construction planning.

Units

Plot area is expressed in: square metres (m²) and hectares internationally; square feet (sq ft) and acres in the United States, United Kingdom, and Commonwealth countries; square feet and square yards in South Asia; Guntha, Bigha, Cent, Marla, Kanal in regional South Asian land measurement; Rai, Ngan, and Wah in Thailand; Pyeong in South Korea; Tsubo in Japan. The TryBuildCalc Plot Area Calculator converts between all major units automatically.

Plot area reference — common residential plot sizes in various markets

Market / Region	Common Residential Plot Size	Approximate m²	Approximate sq ft
India — urban residential	30×40 ft, 40×60 ft, 50×80 ft	111–372 m²	1,200–4,000 sq ft
India — BDA/BBMP layouts	30×40, 40×60 (BDA standard)	111–222 m²	1,200–2,400 sq ft
United States — suburban	0.15–0.5 acres	607–2,023 m²	6,534–21,780 sq ft
United Kingdom — semi-detached	150–300 m²	150–300 m²	1,615–3,229 sq ft
Australia — suburban	400–800 m²	400–800 m²	4,306–8,611 sq ft
Singapore — landed property	150–500 m²	150–500 m²	1,615–5,382 sq ft
UAE — residential villa plot	300–1000 m²	300–1000 m²	3,229–10,764 sq ft
Germany — residential	300–700 m²	300–700 m²	3,229–7,535 sq ft

Built-Up Area (BUA)

Built-up area is the total floor area of a building, measured to the outer face of the external walls. It includes all covered (roofed) areas across all floors of the building — the structural walls, internal walls, columns within the floor plate, covered balconies, utility ducts, and stairwells — in addition to the internal usable space.

Built-up area is the area for which a building permit is typically obtained and against which Floor Area Ratio (FAR) is calculated. It is the total area "built" — hence the name.

What It Includes

All internal floor area within the external walls
The thickness of all external and internal walls
Covered balconies and verandahs (fully enclosed or partially enclosed)
Internal columns and pilasters within the floor plate
Stairwells and lift shafts at each floor level
Covered utility ducts and service shafts
Covered car parking within the building footprint
Mezzanine floors and loft areas with adequate headroom

What It Excludes

Open (uncovered) terraces and open balconies
Underground basement areas in some jurisdictions (varies by local building code)
Uncovered stilt parking in some jurisdictions
Overhead water tanks and service rooms on the roof (subject to local rules)
Areas below minimum headroom height (typically 2.1m — varies by jurisdiction)

Relationship

Built-up area is always larger than carpet area. The difference is the wall area, duct areas, and any non-livable covered spaces. Typically: Built-up Area = Carpet Area + 15–30% depending on wall thickness, building type, and proportion of common areas.

For a single residential floor in an apartment building: the carpet area of individual flats may represent 70–85% of the built-up area of that floor. The remaining 15–30% is walls, stairwell, lift, and service areas.

Local Terminology

Title

Built-Up Area Terminology by Country

Country / Region	Term Used	Standard Authority	Notes
India	Built-up Area (BUA)	Local Municipal Corporations, RERA	RERA requires builders to disclose both built-up and carpet area separately
United Kingdom	Gross Internal Area (GIA)	RICS (Royal Institution of Chartered Surveyors)	GIA measured to internal face of external walls — slightly different from BUA
United States	Gross Living Area (GLA) or Gross Building Area (GBA)	ANSI Z765 standard	GLA excludes basement and garage; GBA includes all covered areas
Australia	Gross Floor Area (GFA)	State planning authorities	Definition varies by state — check local planning rules
Singapore	Gross Floor Area (GFA)	Urban Redevelopment Authority (URA)	URA defines GFA for development charge and planning permission
European Union	Gross Floor Area / Bruttogrundfläche (BGF)	ISO 9836	ISO 9836 provides international standard for floor area measurement
Japan	Yuka Menseki (床面積)	Building Standards Act	Measured to centreline of external walls
UAE / GCC	Built-Up Area (BUA) or Gross Floor Area	RERA (Dubai), ADDA (Abu Dhabi)	Definitions vary between emirates

Carpet Area

Carpet area is the net usable floor area within a property — the area where you can actually lay a carpet. It is measured to the inner face of the enclosing walls, excluding all wall thicknesses, structural columns, and any area that cannot be used for living, working, or storage.

Carpet area is the truest measure of the usable space you are getting in a property. It is the number that determines whether your furniture fits, how many people can work in an office, and whether the room feels spacious or cramped. A 2,000 sq ft built-up area flat may have only 1,400–1,600 sq ft of carpet area — the space you actually live in.

What It Includes

All internal floor area within the finished internal wall faces
Bedrooms, living rooms, dining rooms, kitchens, bathrooms — measured to the internal face of the walls enclosing each room
Internal corridors and passages within the private flat or unit
Internal staircases within a private dwelling (not common staircases in a multi-unit building)
Loft storage areas within the unit if accessible and with adequate headroom
Open balconies that are part of the private unit (varies by jurisdiction — some authorities exclude balconies from carpet area)

What It Excludes

The thickness of all walls — both external and internal partition walls
Structural columns and beams within the floor area
Common areas of a multi-unit building — lobbies, common corridors, staircases, lift areas, security room, generator room
Ducts and shafts for services (plumbing, electrical, HVAC)
Areas below minimum usable headroom (typically 2.1m)
Covered common terraces and common utility areas

Rera Definition

In India, the Real Estate (Regulation and Development) Act 2016 (RERA) provides a legal definition of carpet area: "The net usable floor area of an apartment, excluding the area covered by the external walls, areas under services shafts, exclusive balcony or verandah area and exclusive open terrace area, but includes the area covered by the internal partition walls of the apartment." RERA mandates that all residential property sales in India must be transacted on carpet area — not super built-up area or built-up area — making the carpet area the legally binding measurement for residential property transactions in India.

International Equivalents

Title

Carpet Area Equivalents by Country

Country	Term	Standard / Authority	Notes
India	Carpet Area	RERA 2016	Legally mandated for residential sales; excludes balcony and external walls
United Kingdom	Net Internal Area (NIA)	RICS Code of Measuring Practice	NIA excludes walls, columns, stairwells, and plant rooms; the standard for office and retail lettings
United States	Net Rentable Area (NRA) or Usable Area	BOMA (Building Owners and Managers Association)	BOMA distinguishes usable, rentable, and gross areas for commercial; residential uses GLA or livable area
Australia	Net Lettable Area (NLA)	Property Council of Australia (PCA)	NLA is the equivalent of carpet area for commercial property; residential uses internal floor area
European Union	Net Floor Area / Nutzfläche (NF)	ISO 9836 / DIN 277	NF is the functional floor area; sub-classified by use type under ISO 9836
Japan	Sennyu Menseki (専有面積)	Condominium Act	Exclusive area of a condominium unit; typically measured to centreline of walls
Singapore	Strata Area	Strata Titles Act	Strata area is the legally registered area of a strata unit; roughly equivalent to built-up area, not carpet area
UAE / Dubai	Internal Area	RERA Dubai	RERA Dubai distinguishes internal area (≈ carpet area) from built-up area in project registrations

How the Three Areas Relate to Each Other

The three areas are nested: carpet area is the smallest, built-up area is larger, and plot area is the largest. Each contains the previous plus additional elements.

Relationship

Formula

Carpet Area < Built-Up Area < Plot Area (always)
Built-Up Area = Carpet Area + Wall area + Common area share (in multi-unit buildings)
Ground Coverage Area ≤ Plot Area (the building footprint cannot exceed the plot)
Total Built-Up Area across all floors = Ground Coverage Area × Number of floors (approximately)

Typical Ratios

Title

Typical Ratios — Residential Apartment Building

Area Type	Typical % of Built-Up Area	Example (1,000 sq ft BUA flat)
Carpet Area (usable space)	70–85%	700–850 sq ft
Wall thickness (external + internal)	8–12%	80–120 sq ft
Balcony (covered)	3–8%	30–80 sq ft
Common area loading (proportionate share)	5–15%	50–150 sq ft
Total Built-Up Area	100%	1,000 sq ft

Super Built Up

In Indian real estate, a fourth term — Super Built-Up Area (SBUA) — is commonly used. Super built-up area = built-up area of the individual unit + a proportionate share of common areas (staircases, lifts, lobby, security room, generator room, and sometimes even amenities like the gym or swimming pool area). SBUA is always larger than built-up area, which is larger than carpet area. Before RERA, many Indian developers sold flats on super built-up area with a "loading factor" of 1.25–1.40 — meaning buyers paid for 1,250–1,400 sq ft of super built-up area but received only 1,000 sq ft of carpet area. RERA made it mandatory to state and sell on carpet area, eliminating this practice for registered projects.

Floor Area Ratio (FAR) and Floor Space Index (FSI)

Floor Area Ratio (FAR) — called Floor Space Index (FSI) in India — is the ratio of total built-up area permitted on a plot to the plot area. It is the primary planning tool that controls how intensively land can be developed. FAR determines how much building is permitted on a given plot of land.

Formula

Title

FAR / FSI Formula

Equations

FAR = Total Built-Up Area of all floors ÷ Plot Area
Maximum Permitted Built-Up Area = FAR × Plot Area
Example: Plot area = 300 m², Permitted FAR = 1.5 → Maximum BUA = 300 × 1.5 = 450 m²

Typical FAR / FSI values by city and land use type

Location / Authority	Residential FAR	Commercial FAR	Notes
Mumbai (MCGM) — Island City	1.33 (base) to 3.0 (with TDR)	Up to 5.0 with TDR	Transfer of Development Rights (TDR) allows additional FAR purchase
Bengaluru (BBMP)	1.75–3.25 depending on road width	2.5–3.5	FAR increases with frontage road width — wider roads allow taller buildings
Delhi (DDA)	1.2–3.5 depending on zone	2.0–5.0 (TOD zones)	Transit Oriented Development zones have higher FAR near metro stations
Hyderabad (GHMC)	1.5–4.0 depending on zone	2.0–5.0	G+3 permissible in most residential areas without special approval
New York City (NYC)	0.5 (low density) to 15 (Manhattan)	Up to 25 in special zones	FAR varies dramatically by zoning district and floor type
Singapore	1.4–5.6 depending on zone	Up to 5.6	Controlled by URA Master Plan plot ratio
London (Greater London)	No explicit FAR — controlled by height and density policy	Density measured in habitable rooms per hectare	UK uses density matrices, not a simple FAR number
Dubai	1.0–3.0 typical residential	Up to 5.0+ in commercial zones	Varies by emirate and specific zone
Sydney	0.5–2.5 typical residential	Up to 10 in CBD	Controlled by Local Environmental Plan (LEP)

Implications

FAR directly determines how many floors you can build — a plot with FAR 2.0 and 300 m² can have 600 m² of total built-up area across all floors (e.g. 2 floors of 300 m² each, or 4 floors of 150 m² each).
FAR is applied to the net plot area in most jurisdictions — after deducting road setbacks and reservations. Buying a 500 m² plot with a 50 m² road setback gives only 450 m² of FAR-applicable area.
Exceeding FAR without approval is an unauthorised structure. In many cities (Mumbai, Bengaluru, Hyderabad), unauthorised excess construction is subject to compulsory demolition and heavy penalties.
FAR can sometimes be purchased or transferred (TDR — Transfer of Development Rights) in markets like Mumbai, allowing additional built-up area beyond the base FAR.
Different floors and uses may have different FAR implications — basement parking may be exempt from FAR in some jurisdictions; terraces and service floors may or may not count toward FAR depending on local rules.

Ground Coverage (Site Coverage)

Ground coverage (also called site coverage) is the percentage of the plot area covered by the building footprint at ground level. It controls how much of the plot is occupied by the building versus remaining as open space — setbacks, garden, open parking, and green areas.

Formula

Title

Ground Coverage Formula

Equations

Ground Coverage (%) = (Building Footprint Area ÷ Plot Area) × 100
Maximum Permitted Footprint = (Ground Coverage % ÷ 100) × Plot Area
Example: Plot = 300 m², Ground Coverage = 60% → Maximum footprint = 180 m²

Typical ground coverage limits by jurisdiction

Jurisdiction	Typical Residential Coverage	Notes
India — general residential zone	50–70%	Varies by plot size and road width; smaller plots often get higher coverage allowance
United States — suburban residential	30–50%	HOAs and zoning codes often impose lower maximums for open space
United Kingdom	Typically not explicitly stated	Controlled by daylight, sunlight, and amenity space standards rather than a fixed %;
Singapore	40–50% typical	URA controls both plot ratio (FAR) and site coverage
Australia — suburban	50–60% typical	Varies significantly by local council
Germany	GRZ (Grundflächenzahl) 0.3–0.6	GRZ is the German FAR equivalent for ground coverage
Dubai	40–60% depending on zone	Setback requirements effectively limit coverage

Relationship

Ground coverage and FAR together define the building envelope. A high FAR with a low ground coverage means a tall, slender building. A high FAR with a high ground coverage means a low, wide building. The combination determines the building's urban form. Example: Plot 500 m², FAR 2.0, Ground Coverage 50% → Maximum built-up area = 1,000 m²; Maximum footprint = 250 m²; Minimum floors = 1,000 ÷ 250 = 4 floors.

Setbacks and Their Effect on Usable Area

Setbacks are minimum distances that must be maintained between the building and the plot boundary. They reduce the buildable area within the plot and determine how much of the plot area is actually available for construction.

Types

Type

Front setback (building line)

Description

Minimum distance from the front boundary (road-facing side) to the building face. Typically 1.5–6m depending on road width and jurisdiction. The front setback zone may be used for driveway, garden, or compound wall but not for covered construction.

Type

Rear setback

Description

Minimum distance from the rear boundary to the building. Typically 1.5–3m for residential. Ensures light and air access to the rear neighbours and the building itself.

Type

Side setbacks

Description

Minimum distance from each side boundary to the building. May be zero (zero lot line) in dense urban areas; typically 1.0–3.0m in suburban residential zones.

Type

Road widening reservation

Description

In many developing cities, road widening reservations reduce the effective plot depth. A plot with 40 ft depth may lose 5–10 ft to road widening — reducing the buildable depth to 30–35 ft. This reservation is typically shown in the approved layout plan and must be verified before construction.

Buildable Area Formula

Title

Calculating Net Buildable Area After Setbacks

Example

Plot: 12m wide × 18m deep (216 m²). Setbacks: Front 2m, Rear 1.5m, Side 1m each. Net buildable width = 12 − 1 − 1 = 10m. Net buildable depth = 18 − 2 − 1.5 = 14.5m. Net buildable area = 10 × 14.5 = 145 m². The setbacks remove 71 m² (33%) of the plot area from the buildable zone.

Practical Implications for Property Buyers and Builders

Understanding the difference between these three areas prevents costly mistakes at every stage of property purchase and construction planning.

For Buyers

Title

For Property Buyers

Points

When comparing apartments or flats, always compare on carpet area — not built-up area or super built-up area. Two apartments may have the same built-up area but very different carpet areas depending on wall thickness and common area loading.
In countries with RERA or equivalent disclosure requirements (India, UAE, Singapore), ask for the legal carpet area certificate. Do not rely on the marketing brochure built-up area.
When buying land, verify the plot area in the title document against the physical measurement. In older properties, the registered area and the physical area sometimes differ. Always get a survey confirmation before purchase.
Understand the FAR and ground coverage limits for the plot before buying. A 500 m² plot in a low-FAR residential zone (FAR 0.5) permits only 250 m² of total built-up area — adequate for a modest single home. The same plot in a commercial zone with FAR 2.0 permits 1,000 m² — four times as much.
In markets where property is sold on super built-up area (older Indian projects, some Middle Eastern projects), calculate the loading factor: Loading factor = Super Built-Up Area ÷ Carpet Area. A loading factor above 1.4 means you are paying for 40% more area than you will actually use.

For Builders

Title

For Builders and Homeowners Planning Construction

Points

Calculate FAR headroom before designing: Maximum BUA = Plot Area × Permitted FAR. Subtract existing built-up area (if any) to determine remaining development potential.
Design the building footprint to respect ground coverage limits. The footprint (ground floor area) ÷ Plot Area must not exceed the permitted ground coverage percentage.
Account for setbacks in the usable plot area before calculating the number of floors. A plot that appears to allow 4 floors may effectively allow only 3 once the setback-reduced footprint is applied against the FAR.
In multi-floor buildings, count each floor's built-up area toward the total FAR. Basement parking may be exempt in some jurisdictions — confirm with the local building authority before designing the basement.
Maximise carpet area efficiency by minimising wall thickness (hollow brick or AAC block walls are thinner than solid brick for the same insulation value) and minimising common area loading in apartment projects.

For Real Estate Professionals

Title

For Real Estate and Legal Professionals

Points

Ensure all property sale agreements state the measurement basis clearly — carpet area, built-up area, or super built-up area — and the specific standard or regulation used to define it.
In cross-border transactions, be alert to measurement standard differences. UK Net Internal Area (NIA) is not the same as Indian Carpet Area. US Gross Living Area (GLA) is not the same as Indian Built-Up Area. Use the definitions in the applicable local standard when comparing properties across jurisdictions.
Verify that the built-up area approved in the building permit matches the area in the sale deed. Discrepancies may indicate unauthorised construction that affects the property's legal status.

Quick Reference — Definitions at a Glance

A side-by-side comparison of the three core area measurements and the two derived planning ratios.

Area definitions — quick reference

Term	What It Measures	Includes	Excludes	Used For
Plot Area	Total land within the property boundary	All land within boundary — built and unbuilt	Road outside boundary; road widening reservations	Land purchase, tax assessment, FAR/FSI calculation
Built-Up Area (BUA)	Total covered floor area of the building	All covered floors: internal space + walls + balconies + common areas	Open terraces, uncovered areas, underground car parks (varies)	Building permit, FAR compliance, property registration
Carpet Area	Net usable floor area within the unit	Internal floor area to face of walls	Wall thickness, common areas, columns, ducts	Property sale agreements, rental pricing, space planning
Super Built-Up Area (India)	BUA + proportionate common area share	Unit BUA + share of lobby, lift, staircase, amenities	Nothing (maximum possible area claim)	Older Indian property sales (pre-RERA); now superseded by carpet area
FAR / FSI	Ratio: total BUA ÷ plot area	All built-up area across all floors	Exempt uses (parking, service floors — varies by jurisdiction)	Planning permission, development intensity control
Ground Coverage	Ratio: building footprint ÷ plot area	Building footprint at ground level	Open areas, setbacks, driveways, gardens	Planning permission, open space control

Worked Examples

Three worked examples showing how plot area, built-up area, carpet area, FAR, and ground coverage interact in a real planning scenario.

Examples

Example 1 — Independent House on a 30×40 ft Plot (India)

Given

Plot: 30 ft × 40 ft = 1,200 sq ft (111.5 m²). Permitted FSI: 1.75. Permitted ground coverage: 60%. Setbacks: Front 2m, Rear 1m, Side 1m each.

Steps

Net buildable width after side setbacks: 9.14m − 1m − 1m = 7.14m
Net buildable depth after front and rear setbacks: 12.19m − 2m − 1m = 9.19m
Maximum footprint: 7.14 × 9.19 = 65.6 m²
Ground coverage check: 65.6 ÷ 111.5 = 58.8% — within 60% limit
Maximum total BUA: 111.5 × 1.75 = 195.1 m²
Maximum floors: 195.1 ÷ 65.6 = 2.97 → 2 floors + partial third (or 2 floors with some unused FAR)
Carpet area (approximately 78% of BUA): 195.1 × 0.78 = 152.2 m² ≈ 1,638 sq ft

Result

A 1,200 sq ft plot with FSI 1.75 yields approximately 1,600 sq ft of carpet area across 2–3 floors — 33% more usable area than the plot size alone suggests.

Example 2 — Apartment Purchase Comparison (Any Market)

Given

Builder's advertisement: Flat A = 1,200 sq ft (Super Built-Up Area). Flat B = 1,000 sq ft (Built-Up Area). Flat C = 850 sq ft (Carpet Area). Same price per quoted sq ft.

Steps

Flat A: Super BUA 1,200 sq ft. Assume loading factor 1.30 → BUA = 1,200 ÷ 1.30 = 923 sq ft. Assume carpet is 80% of BUA → Carpet = 923 × 0.80 = 738 sq ft
Flat B: BUA 1,000 sq ft. Assume carpet is 80% of BUA → Carpet = 1,000 × 0.80 = 800 sq ft
Flat C: Carpet Area 850 sq ft. This is the usable area directly stated.
Flat C has the most usable space (850 sq ft carpet) despite appearing smaller than Flat A (1,200 sq ft SBUA) in the advertisement.

Result

Always convert all quoted areas to carpet area before comparing. Flat A at 1,200 sq ft SBUA may have only 738 sq ft of actual living space — less than Flat C at 850 sq ft carpet area.

Example 3 — Development Potential of a Commercial Plot (International)

Given

Plot: 500 m². Permitted FAR: 3.0. Ground coverage limit: 60%. Setbacks consume 20 m² of the plot, leaving 480 m² as effective FAR base.

Steps

Maximum total built-up area: 480 × 3.0 = 1,440 m²
Maximum footprint (ground coverage): 480 × 60% = 288 m²
Minimum floors to achieve maximum FAR: 1,440 ÷ 288 = 5 floors
If basement parking is exempt from FAR: the 5 floors are all above ground; basement can be added for parking without consuming FAR
Net rentable (carpet equivalent) area per floor at 80% efficiency: 288 × 0.80 = 230 m² per floor
Total net rentable area: 230 × 5 = 1,152 m²

Result

A 500 m² commercial plot with FAR 3.0 and 60% coverage can yield 1,152 m² of net rentable space across 5 floors plus basement parking — 2.3× the plot area in usable commercial space.

Related calculators

Use these calculators when you need to turn this reference information into project quantities:

Plot Area Calculator
Calculate plot area in sq ft, sq yards, m², acres, Guntha, Cent, and Marla — with perimeter and cost estimation.
Land Leveling Calculator
Estimate earthwork volume and cost for leveling a plot to a target finished level.
Excavation Calculator
Calculate excavation volume for foundations, basements, and site preparation.
Concrete Slab Calculator
Estimate concrete, cement, sand, and aggregate for RCC slabs.
Wall / Masonry Calculator
Calculate bricks and mortar for compound walls and boundary walls using plot perimeter.

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