Who Owns the Extra FSI? Karnataka's New Apartment Law Gives It to Flat Owners
The Karnataka Apartment (Ownership and Management) Bill, 2026, now gazetted as Act No. 45 of 2026 but not yet in force, fixes each flat's undivided share in land and common areas by the ratio of its private area, and says any additional development rights or FSI arising from changes in planning rules belong collectively to apartment owners. This guide works through the bill's own numbers for Bengaluru buyers.
139.29 square metres. That is the share of a 300 square metre plot that Karnataka's new apartment law assigns, in its own worked example, to a flat with a private area of 130 square metres in a two-flat building. The bigger flat, with 150 square metres of private area, gets 160.71. For Bengaluru buyers who have struggled to get a straight answer on undivided share, the law now spells out the formula.
It goes further. Section 8 of the Karnataka Apartment (Ownership and Management) Bill, 2026 says that extra floor space index or development rights arising from a future change in planning rules belong to the flat owners, not the builder. The law was gazetted on 15 October 2026 as Act No. 45 of 2026 and is not yet in force, according to FoxMandal's 16 October update. Our overview of the Act explains its scope.
The short answer. Under the bill, each flat's undivided share in the land and common areas is in proportion to its private area, which is carpet area plus external walls and exclusive balconies plus a third of any exclusive terrace, unless the declaration or deed says otherwise. Any additional built-up area or development rights arising from changes to FSI, FAR or zoning rules belong collectively to the owners and are shared in the same proportion; the promoter can keep only the share tied to unsold flats unless owners expressly transfer it. The trade-off: owners gain a valuable collective right, but using it will need collective decisions and approvals, so the right is real but not automatic money in hand.
How is your share of the land worked out?
Section 3(1) gives every owner exclusive ownership of the apartment plus an undivided, non-exclusive interest in the land and the common areas. Section 3(2) says the proportion is the ratio of the apartment's private area to the total private area of all apartments, unless the declaration or deed of transfer provides otherwise under the Act.
The bill's illustration has two flats. Flat A has 100 square metres of carpet area, 20 of walls and balcony and a 30 square metre terrace counted at a third, 10, for a private area of 130. Flat B has 120 of carpet area and 30 of walls and balcony, a private area of 150. On a 300 square metre plot, A's land share is 130/280 of 300, or 139.29 square metres, and B's is 150/280 of 300, or 160.71.
For mixed-use projects, the first proviso to section 3(2) lets the declaration or deed allocate shares by the relative land and built area dedicated to each use. We looked at how undivided share shows up in sale deeds in our explainer on undivided share in sale deeds.
| Item in the bill's illustration | Flat A | Flat B |
|---|---|---|
| Private area | 130 sq m | 150 sq m |
| Share of 140 sq m built-up common area | 65 sq m | 75 sq m |
| Super built-up area | 195 sq m | 225 sq m |
| Undivided share of 300 sq m land | 139.29 sq m | 160.71 sq m |
| Share of a hypothetical 100 sq m of extra built-up area | 46.43 sq m | 53.57 sq m |
The last row is our own extension of the bill's example, using the private-area ratio that section 8 prescribes.
What exactly is "private area"?
The bill uses private area as the yardstick for land share, extra development rights and, under section 9, common profits. Its illustration builds private area from three parts: carpet area as defined under the RERA Act; the area of external walls and exclusive balconies; and 33 per cent of any terrace, lawn, garden or open space conveyed exclusively with the flat, or whatever percentage the title deed specifies.
Private parking is treated separately. The bill says the area of a private parking space is not included in the carpet area, private area or super built-up area unless expressly conveyed as part of the apartment. So two flats with the same carpet area can still have different private areas if one has a larger balcony or an exclusive terrace.
How is land share different from super built-up area?
They do different jobs. Super built-up area adds a share of built-up common areas to private area, and section 25 uses it as the general basis for maintenance charges. Private area, without the common-area loading, sets your share of the land, the common areas and any additional development rights.
In the bill's illustration, Flat A's super built-up area is 195 square metres and its private area is 130, but its land share of 139.29 square metres follows the private-area ratio, not the super built-up figure. When you compare a cost sheet with a draft deed, check which measure each number is based on.
Who gets extra FSI if the rules change?
Section 8(1) says any additional built-up area, development rights or development potential arising in respect of the project land because of a change in planning regulations, zoning regulations, FSI, FAR or for any other reason shall belong collectively to the apartment owners, and shall be distributed or used in proportion to each apartment's private area to the total private area.
Section 8(2) adds that no promoter or developer shall claim or retain any right over such additional area or development rights, except to the extent of the undivided interest in land attached to apartments still unsold, unless the right is expressly transferred by the owners under the Act.
In practice, if a future rule change were to allow more construction on a fully sold Bengaluru project, the bill puts that potential in the owners' hands. If the project were partly unsold, the promoter would hold only the share attached to its unsold flats.
Does that let owners build more on their own?
No, not individually. The second proviso to section 3(2) says nothing in that section confers on an owner the right to carry out structural alterations to the building or common areas, except in line with the Act, the bye-laws and building regulations. Using any extra potential would mean collective decisions and approvals. Section 24(6) of the bill, for instance, requires the consent of at least 75 per cent of owners and planning approval for any alteration, reconstruction or variation affecting the number or area of apartments.
Can you split, merge or transfer your flat freely?
Section 4 makes the apartment with its undivided interest heritable and transferable immovable property that can be sold, mortgaged, leased, gifted, exchanged or bequeathed. Its proviso says it cannot be partitioned or sub-divided except with the competent authority's approval and under applicable laws and building regulations, with the undivided interest re-apportioned.
Section 7 says that if two adjacent flats are combined, they remain separate apartments with their own numbers and land shares, and the merger cannot affect structural stability, others' use of common areas, or building services and parking.
What happens to your land share if the building is redeveloped?
Section 48 of the bill lets owners of at least 75 per cent of the apartments in a project approved as a single development plan resolve to redevelop, by written consent in a general body meeting, subject to approval by the Second Appellate Authority, after which the resolution binds all owners. Section 49(3) says that once the Competent Authority certifies removal of the property from the Act for redevelopment, the property is deemed owned in common, and each owner's share corresponds to the undivided interest in land and common areas previously attached to the apartment.
That is where an accurate land share pays off: it becomes your stake in the plot when the building is rebuilt.
What should a Bengaluru buyer check now?
The Act is not in force yet, but you can use its formula to test what you are being sold. If you are looking at a project such as White Lotus Amanvana on IVC Road, or any other, ask:
- What is the private area of my flat, broken into carpet area, walls and balconies, and any exclusive terrace?
- What is the total private area of all apartments in the project?
- What undivided share of land does my sale deed give me, and does it match the private-area ratio?
- Is the project mixed-use, and if so, how will the declaration allocate land between uses?
- Does the agreement claim any right for the promoter over future FSI or development rights?
- How many flats remain unsold, since the promoter's residual share depends on them?
- Will the declaration and deed record the land share clearly enough to support any future redevelopment decision?
Frequently asked questions
How is a flat's undivided share in land calculated under Karnataka's new law?
Section 3(2) of the bill fixes the undivided share in land and common areas in the ratio of the apartment's private area to the total private area of all apartments, unless the declaration or deed provides otherwise. In the bill's illustration, a 130 square metre private area gets 139.29 square metres of a 300 square metre plot.
Who owns additional FSI if Bengaluru planning rules change?
Section 8(1) of the bill says any additional built-up area, development rights or potential arising from changes in planning or zoning regulations, FSI or FAR belongs collectively to apartment owners, and is distributed or used in proportion to each apartment's private area.
Can a builder keep the extra FSI after selling the flats?
Section 8(2) says no promoter or developer shall claim or retain any right over additional built-up area or development rights, except to the extent of the land share attached to apartments still unsold, unless apartment owners expressly transfer that right under the Act.
Can I partition or sub-divide my flat under the new law?
Section 4(2) of the bill says an apartment with its undivided interest shall not be partitioned or sub-divided except with the approval of the competent authority and under applicable laws and building regulations, with the undivided interest in land and common areas re-apportioned accordingly. Plan any split well ahead of a sale.
This article summarises the Karnataka Apartment (Ownership and Management) Bill, 2026 as introduced and a law firm's update on its enactment, for information. The extra built-up area figures are illustrative. The final Act and rules govern; it is not legal advice.
Last updated 2026-11-12. PropNewz Team.
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