Loading factor: how to calculate it from a flat brochure

1.3.1 What is loading factor in a flat?

Loading factor is the area added to the carpet area to reach the quoted area of a flat. A flat brochure can quote a super built-up area. That figure adds the walls, the balconies and a share of the common areas to the carpet area. The common formula states this addition as a percentage of the carpet area. For example, a loading factor of 30 percent means the quoted area is 1.3 times the carpet area. The term comes from market practice. The Real Estate (Regulation and Development) Act, 2016 (the RERA Act) does not use the words “loading” or “super built-up area”. The Act defines only “carpet area”, in section 2(k). So loading is a convention, and each builder can calculate the quoted area differently. For a buyer, the loading factor is useful for one job. It converts a price per square foot of super built-up area into a price per square foot of the space you actually use.

1.3.2 How do you calculate the loading percentage?

You calculate the loading percentage from two figures: the quoted area and the carpet area. The common market formula is: loading percentage = (super built-up area − carpet area) ÷ carpet area × 100. Take an example for illustration only. A brochure quotes 1,400 sq ft of super built-up area for a flat with 1,000 sq ft of RERA carpet area. The difference is 400 sq ft. 400 divided by 1,000 is 0.40, so the loading is 40 percent. Some people divide by the super built-up area instead. With the same figures, 400 divided by 1,400 gives about 28.6 percent. Others state a ratio, such as 1.4, which is super built-up area divided by carpet area. All three describe the same flat. No Act or rule fixes one formula. When a builder or agent gives you a loading figure, ask which formula they used and ask for both areas in writing.

Method	Formula	Result for 1,400 sq ft quoted and 1,000 sq ft carpet
Loading on carpet area (common)	(Super built-up − carpet) ÷ carpet × 100	40%
Loading on super built-up area	(Super built-up − carpet) ÷ super built-up × 100	About 28.6%
Ratio	Super built-up ÷ carpet	1.4
Carpet efficiency	Carpet ÷ super built-up × 100	About 71.4%

Illustrative figures only. Use the same method for every project you compare.

The loading also changes the real price. Suppose the builder quotes ₹10,000 per sq ft on the 1,400 sq ft super built-up area. The base price is ₹1.4 crore. Divided by the 1,000 sq ft of carpet area, that is ₹14,000 per sq ft of carpet area. These figures are an illustration, not a market rate.

1.3.3 What does the RERA Act say about carpet area?

The RERA Act defines carpet area and makes the builder disclose it. Section 2(k) says carpet area is “the net usable floor area of an apartment”. It excludes the area under the external walls, the areas under services shafts, and the exclusive balcony or verandah area. It also excludes the exclusive open terrace area. It includes the area under the internal partition walls of the apartment. Section 4(2)(h) says the promoter’s registration application must state “the number, type and the carpet area of apartments for sale”. The application must also state the area of the exclusive balcony or verandah and the exclusive open terrace, if any. Section 11(1) says the promoter must enter these details on the project’s web page on the Authority’s website “for public viewing”. So the K-RERA project page is the place to find the carpet area of your unit type. Section 2(n) lists the “common areas”, such as staircases, lifts, lobbies, parks and community facilities.

The Act does not set a limit on how much common area a builder can add to the quoted area. The Act text does not contain the terms “super built-up area” or “loading”. Sachi did not find a Karnataka limit in the sources checked for this chapter. Section 11(4)(f) gives the buyer the apartment by a registered conveyance deed. The deed transfers “the undivided proportionate title in the common areas” to the association of allottees, not to the individual buyer.

1.3.4 How does the Bangalore e-khata record super built-up area?

The Greater Bengaluru Authority (GBA) records the super built-up area of each flat in its e-khata system, with a published formula. The apartment form on the GBA e-Aasthi 2.0 portal lists four area terms. “Flat Carpet Area” is the inside floor area “where essentially carpet can be laid”. “Flat Built-Up Area (FBUA)” is described as “Carpet Area + Wall thickness + balconies etc.” “Special Private Area (SPA)” is area that only the flat owner uses, such as a private lawn or private terrace. “Share in Common Built-Up Area (SCBA)” is the flat’s share of the project’s common built-up area. The English form then gives the formula: “Super Built-Up Area = SCBA + FBUA + (0.33 * Spl Private Area)”. So the e-khata counts only one third of a private terrace or garden. The form also checks that the built-up area is smaller than the super built-up area. This is an e-khata record formula. It is not a rule on how a builder can price a flat.

The portal text is not consistent, so read the form with care. The same English form also says “Flat Built-Up Area should be excluding balconies”, which conflicts with the FBUA description above. One Kannada label of the formula reads FBUA + SPA + CBUA, without the 0.33 factor. Another Kannada label for multi-storey flats includes the 0.33 factor. The portal calculation uses the 0.33 factor. Ask the builder to show you how your flat’s areas will appear in the e-khata.

Term on the GBA form	Portal description	Counted in the GBA super built-up formula
Flat Carpet Area	Inside floor area where carpet can be laid	Through FBUA
Flat Built-Up Area (FBUA)	Carpet area + wall thickness + balconies etc. (another note on the same form says to exclude balconies)	In full
Special Private Area (SPA)	Private lawn, private terrace or garden owned only by the flat owner	0.33 times the area (English formula)
Share in Common Built-Up Area (SCBA)	The flat’s share of the project’s common built-up area	In full

Source: GBA e-Aasthi 2.0 portal, apartment and multi-storey khata application form (visible only inside the form flow), checked 9 October 2026.

1.3.5 How do you compare loading between two Bangalore projects?

Compare two projects only after you put both on the same base, which is the RERA carpet area of the exact unit. Brochures can label the quoted area as built-up, super built-up, saleable or super area. The label alone does not tell you what is inside. One builder can include balconies and a clubhouse share. Another builder can exclude them. So the same flat can show different loading figures in two brochures. Start with the carpet area on the K-RERA project page and in the draft agreement for sale. Then ask each builder for a written area statement. The statement must split the quoted area into carpet area, walls, balconies, private terrace and common area share. Use one formula for both projects. Then convert each quoted price into a price per square foot of carpet area. That number is comparable across projects, even when the loading figures are not. If a builder cannot give the split, record the loading as unknown.

1. Find the carpet area of your unit type on the builder’s K-RERA project page.
2. Check that the same carpet area appears in the draft agreement for sale.
3. Ask the builder for the written split of the quoted area.
4. Calculate the loading with one formula for every project.
5. Divide the total base price by the carpet area to get the price per carpet sq ft.

Check	Project A (illustration)	Project B (illustration)
Quoted super built-up area	1,400 sq ft	1,300 sq ft
RERA carpet area	1,000 sq ft	1,000 sq ft
Loading on carpet area	40%	30%
Quoted rate per super built-up sq ft	₹10,000	₹11,000
Base price	₹1.40 crore	₹1.43 crore
Price per carpet sq ft	₹14,000	₹14,300

Illustrative figures only. In this example, Project A has higher loading but a lower price per carpet sq ft.

1.3.6 Does a higher loading factor mean you are getting less value?

A higher loading factor does not, by itself, mean less value. The loading only shows how much area is outside the carpet area. It does not show what that area contains. A project with large lift lobbies, a clubhouse or wide corridors can show high loading. Those spaces can add to daily comfort. A project with the same loading can also count areas that add little to your use. The loading also does not show daylight, room shape, structural quality or legal status. What it does change is your real price. A buyer who reads only the rate per super built-up sq ft can miss a higher price per carpet sq ft. The common areas also carry running costs. If the maintenance charge is set per square foot of quoted area, a higher quoted area means a higher charge. Sachi did not verify how Bangalore projects set this basis, so check it in the agreement. Use loading as a prompt to ask questions, then decide on the carpet price and the unit plan.

Ask the builder three questions in writing. First, which areas make up the difference between the quoted area and the carpet area? Second, on which area does the builder calculate the maintenance charge? Third, will the flat’s e-khata show the same super built-up area as the brochure?