Carpet Area vs Built-Up vs Super Built-Up: How to Calculate What You Actually Pay For

The Most Misunderstood Metric in Real Estate

If you ask ten different builders in Visakhapatnam to quote the area of a "1,200 sq.ft." flat, you will receive ten completely different usable apartment sizes. One builder's 1,200 sq.ft. might offer an 850 sq.ft. carpet area, while another builder's 1,200 sq.ft. flat might barely provide 760 sq.ft.

Why this discrepancy? Because of how Carpet Area, Built-Up Area, and Super Built-Up Area (SBUA) are computed and loaded.

1. Deconstructing the Three Area Definitions

+---------------------------------------------------------------+
|  SUPER BUILT-UP AREA (SBUA) = Built-Up + Common Area Share    |
|  +---------------------------------------------------------+  |
|  |  BUILT-UP AREA (Plinth Area) = Carpet + Walls + Balcony |  |
|  |  +---------------------------------------------------+  |  |
|  |  |  RERA CARPET AREA: Net Usable Floor Living Space  |  |  |
|  |  +---------------------------------------------------+  |  |
|  +---------------------------------------------------------+  |
+---------------------------------------------------------------+

A. RERA Carpet Area

This is the actual floor area you can physically lay a carpet on.

• Includes: Bedrooms, living room, dining room, kitchen, bathrooms, and the thickness of internal partition walls.
• Excludes: External perimeter walls, utility ducts, lift lobbies, and external balconies.

B. Built-Up Area (Plinth Area)

Calculated by measuring the outer perimeter of the apartment.

• Formula: RERA Carpet Area + Thickness of External Walls + Exclusive Balconies & Verandahs.
• Typically 10% to 15% larger than the carpet area.

C. Super Built-Up Area (Saleable Area)

The total metric on which builders traditionally calculate the base price.

• Formula: Built-Up Area + Proportionate Share of Common Areas (corridors, staircase, lift well, generator room, watchman room).

2. How to Compute the Loading Percentage

The loading factor represents the proportion of common spaces added to your private space:

$$\text{Loading \%} = \left( \frac{\text{Super Built-Up Area} - \text{Carpet Area}}{\text{Carpet Area}} \right) \times 100$$

Practical Example: The SV Constructions Standard

Let's calculate the efficiency of our 3 BHK unit at Sri Venkateswara Aranya:

• Super Built-Up Area: 1,450 sq.ft.
• RERA Carpet Area + Balconies: 1,190 sq.ft.
• Mathematical Loading: 21.8%

Contrast this with many speculative projects where an advertised 1,450 sq.ft. apartment yields only 1,020 sq.ft. of carpet space (a 42% loading), forcing buyers to pay for phantom square footage.

Buyer's Floor Plan Inspection Checklist

• Does the agreement of sale clearly state the RERA Carpet Area in square meters and square feet?
• Are balcony and utility areas listed as distinct line items?
• Is the corridor width at least 6 to 7 feet wide?
• Are the walls between adjacent flats full 9-inch brickwork rather than flimsy 4-inch partitions?