Common area encroachment — what an owner cannot simply take

It starts small and reasonable. The ground-floor flat fences in the strip of garden outside its window, because nobody else was using it. The top-floor flat puts a shed on the terrace. Somebody parks a second car in the visitor bay every night. A decade later the committee tries to reverse one of these and discovers the occupant now describes it as theirs — and genuinely believes it.

These are usually treated as neighbour disputes. They are not. They are changes to property that every owner in the building co-owns, and the law treats that quite differently from a disagreement between two flats.

You already own a share of it

The thing that makes encroachment different from rudeness is that common areas are not unowned space waiting for an occupant. Every apartment owner holds an undivided interest in them, attached to their flat and inseparable from it.

That structure is consistent across Indian apartment law even though the statute differs by state. Delhi's Apartment Ownership Act gives each owner an undivided interest in the common areas "as specified in the Deed of Apartment" (section 4(3)). Karnataka charges common expenses by percentage of undivided interest under KAOA section 10. Tamil Nadu's 2022 Act ties the undivided interest to carpet-area ratio and says it "shall not be separated from the apartment."

Central law says the same thing about what counts as common. RERA section 2(n) lists, among common areas, "the common basements, terraces, parks, play areas, open parking areas and common storage spaces."

So when someone encloses part of a terrace, they are not occupying spare space. They are taking exclusive use of something every other owner holds a registered share in. That is why "nobody was using it" is not a defence, and why long use does not quietly convert into ownership the way people assume.

The Declaration decides — not custom, and not the builder's verbal promise

The genuinely useful distinction is between common areas and limited common areas.

Limited common areas are still common property, but their use is reserved for particular apartments. Crucially, that reservation has to have been made formally and early. Delhi's section 3(q) defines them as areas "designated in writing by the promoter before the allotment, sale or other transfer of any apartment as reserved for use of certain apartment or apartments to the exclusion of the other apartments." Tamil Nadu's 2022 Act uses the same structure, naming car park space, balcony, verandah and open terrace area appertaining to the apartment as examples.

Read that timing requirement carefully, because it settles a lot of arguments:

• If the terrace adjoining a penthouse was designated in writing as a limited common area before sale, that owner's exclusive use is real.
• If it was not, a builder's assurance at booking, an old committee's informal nod, or fifteen years of undisturbed use do not retroactively create the designation.

This is also why the registered Declaration matters so much, and why committees that cannot find theirs are arguing blind. In Karnataka, KAOA section 13(1) requires the Declaration, its amendments, the Deed of Apartment and the floor plans to be registered under the Registration Act,

1. The document exists precisely so that "what is common" is a matter of

record rather than recollection.

Parking deserves its own mention because it is the most contested of these. Open parking is a common area by statutory definition under RERA section 2(n), while a garage — roof plus walls on three sides under section 2(y) — is a different legal object. Can a builder sell you a parking space goes through that distinction and the Supreme Court judgment that is routinely over-quoted in these fights.

Structural work is a separate, harder line

Beyond "who may use this space" there is a second rule that catches a lot of well-meaning renovation.

Delhi's section 11 provides that no apartment owner shall do any work "prejudicial to the soundness or safety of the property or reduce the value thereof or impair any easement," nor add "any material structure or excavate any additional basement or cellar," without first obtaining the consent of all the other apartment owners.

Not a majority. Not the committee's sign-off. All of them.

That is a high bar deliberately, because the thing being protected is the structure everyone lives in. A committee that has been approving structural alterations by simple resolution may be doing something its own statute does not authorise — worth checking against whichever Act governs your building before the next approval rather than after.

What a committee should actually do

Most encroachments become permanent because of how they are handled in the first month, not the fifth year.

1. Find the Declaration and the floor plans before the argument. If you cannot produce the document that says what is common, you will lose the conversation regardless of who is right.
2. Write to the occupant early, and keep the copy. A dated letter recording that use is permissive and not a grant of ownership is the single most useful piece of paper in a dispute five years later.
3. Never let permission go unminuted. If the general body genuinely agrees to let one flat use a space, minute it as revocable permission with a date — see what belongs in your minutes. Unminuted permission is indistinguishable from encroachment later.
4. Separate use from ownership in every communication. People concede "I'm using it" far more readily than "I don't own it," and the record you want is the one where they said the first thing.
5. Treat structural work differently from space. Enclosing a garden strip is a use question. Cutting into a slab is a safety question with a much higher consent threshold.

The short version

• Common areas are co-owned in undivided shares, not unoccupied space — which is why "nobody was using it" isn't a defence.
• RERA section 2(n) puts terraces, basements, parks and open parking in common areas. Section 2(y) makes a garage (roof, three walls) a separate object.
• Limited common areas are reserved for particular flats only if designated in writing, by the promoter, before sale — Delhi section 3(q), and the same structure in Tamil Nadu's 2022 Act. Verbal promises and long use do not create the designation.
• The registered Declaration is what decides, which is why finding it is step one. In Karnataka, registration is required by KAOA section 13(1).
• Structural work clears a higher bar: Delhi section 11 requires the consent of all other apartment owners, not a majority.
• Minute any permission as revocable and dated, or it becomes a claim.

Sources

• The Real Estate (Regulation and Development) Act, 2016 — Section 2 definitions, including 2(n) common areas and 2(y) garage
• The Delhi Apartment Ownership Act, 1986 — full text (Indian Kanoon)
• The Tamil Nadu Apartment Ownership Act, 2022 (Act No. 44 of 2022) — full text (PRS Legislative Research)
• The Karnataka Apartment Ownership Act, 1972 (India Code)