Of all the ways a builder can shortchange a buyer, delivering fewer square feet is the quietest. Nothing looks wrong. The rooms hold furniture, the doors close, the family moves in. The missing area only exists on a tape measure, which is why most buyers never find it, and why the law wrote it a specific remedy when they do.
Key takeaways
- RERA made carpet area the mandatory basis of sale; your agreement must state it, and the delivered flat is measurable against it.
- Model agreements commonly allow up to 3 percent variation; beyond that, you are entitled to a proportionate refund of what you paid for the missing area.
- At the 2025 top-7-city average of Rs 9,260 per sq ft, a 5 percent shortfall on a 650 sq ft flat is about Rs 3 lakh.
- The remedy runs through a Section 31 complaint to your state RERA; regulators are disposing complaints at scale, MahaRERA alone resolved 6,045 in 2025.
The tape measure moment
Meera, our Chennai buyer, ran the measurement on possession day only because her pre-possession checklist told her to. Agreement: 655 sq ft carpet. Tape: a shade over 622. That is a 5 percent shortfall, and at her per-square-foot price it came to roughly Rs 2.9 lakh, quietly missing. The site manager's first response was the one every buyer hears: "sir, some variation is normal". He was partly right, which is exactly why the details below matter. Names and numbers in this story are illustrative.
What the law promised you
Before RERA, flats were sold on super built-up area, an elastic number that included your share of lobbies, shafts and marketing imagination. The Act ended that: carpet area has a statutory definition (Section 2(k), the net usable floor area within the walls, excluding external walls, service shafts, balconies and open terraces, but including internal partition walls), and the sale must be on carpet area, stated in the agreement. If the definitions still feel slippery, our explainer on carpet vs built-up vs super built-up untangles them.
That definitional move is what makes your claim possible. A promise measured in an elastic unit cannot be broken; a promise measured in a statutory unit can.
Two provisions then do the work:
- The tolerance. Model agreements for sale, Maharashtra's being the best known, permit a variation of up to 3 percent in carpet area between agreement and delivery. Within tolerance, no claim; construction is not laser-cut.
- The refund. For shortfall beyond the tolerance, the buyer is entitled to a refund of the proportionate price for the missing area, and RERA's refund provisions carry prescribed interest. Separately, Section 14 bars the promoter from altering your unit's plans without your consent, and Section 18 governs the broader refund-with-interest machinery when the promoter fails contractual obligations.
What a shortfall actually costs
An analogy makes the stakes intuitive: buying carpet area is buying gold by weight. If the jeweller's bill says 50 grams and the chain weighs 47.5, nobody calls a 5 percent gap "normal variation"; they call it Rs 15,000. Flats are the same purchase at a bigger scale, only the weighing happens years after the billing.
Source: Computed at ANAROCK Research's top-7-city average price of Rs 9,260 per sq ft, end 2025
Your remedy paths, compared
| Path | Cost | Typical timeline | What you can get |
|---|---|---|---|
| Written claim to the builder with a surveyor's report | Surveyor fee, roughly Rs 5,000 to 15,000 | Weeks, if the builder engages | Proportionate refund or credit note, fastest when the evidence is undeniable |
| Complaint to state RERA (Section 31) | Filing fee of a few thousand rupees | Months; regulators now dispose at scale | Refund of the proportionate amount with applicable interest, and directions to the promoter |
| Adjudicating officer under RERA | Similar filing route | Months | Compensation beyond the refund where loss is shown |
| Consumer commission | Court-fee scale | Often longer than RERA | Refund and compensation; useful for pre-RERA projects |
The volume argument for the RERA route is real: MahaRERA resolved 6,045 complaints in 2025, more than it received in the year, and nationally regulators had disposed of over 1.47 lakh complaints by September 2025 (MoHUA). The forum built for this claim is functioning. The filing mechanics, documents and hearing flow are walked through in how to file a RERA complaint.
What to do this week, if your tape measure disagrees
- Measure properly. A licensed surveyor or architect, measuring per the Section 2(k) definition, signed report. Rs 10,000 spent here anchors a claim worth lakhs.
- Pull the agreement's carpet area and the sanctioned plan. Your claim is the delta between the signed number and the measured one.
- Write to the builder first. A dated claim letter with the report attached, asking for the proportionate refund within a stated period. Many claims end here; the letter also strengthens the complaint if it does not.
- Preserve the payment trail. The refund is proportionate to price actually paid; your demand letters and receipts define it.
- File under Section 31 if stonewalled. Attach the report, the agreement, the letter and the trail.
Do not sign an unconditional possession letter, or a "full and final settlement" at handover, before the measurement. Those documents do not extinguish statutory rights, but they hand the builder an argument and you a delay. Measure first, sign after.
Catching it before possession day
A shortfall discovered at handover is recoverable; one discovered before the final instalment is leverage. The plan-versus-filing gap is often visible earlier: revised sanctioned plans, changed unit mixes in amendments, area changes across filing versions. The Rs 499 ReraGenie buyer report reads a covered project's filings and flags plan revisions, amendment history and the promoter's complaint record, including area and specification disputes on past projects, so the tape-measure moment stops being the first warning. If your agreement is signed and possession is a few quarters away, sign up on ReraGenie and put the project's filing history in your file, with alerts at Rs 499 per 3 months for every new amendment the promoter registers.
The one-line summary
Carpet area is a statutory number, your agreement states it, a tape measure tests it, and beyond 3 percent the missing square feet convert back into rupees, with a regulator built to order the conversion.
This article is educational and not legal advice. For a dispute, consult a lawyer who practices before your state's RERA.
Evaluating a project right now?
The ReraGenie buyer report reads every filing for one project and hands you the verdict, the risks and the questions to ask the builder. Rs 499, one time.
See the buyer report