What the statute includes and excludes
| Included | Excluded |
|---|---|
| Net usable floor area of all rooms | External walls |
| Area under internal partition walls | Areas under service shafts |
| Kitchen and bathroom floor area | Exclusive balcony or verandah area |
| Internal circulation | Exclusive open terrace area |
| All common areas of the building |
The one difference that matters
Conventional carpet area — the number you get by laying a tape inside each room — excludes internal partition walls, because you cannot carpet a wall. RERA includes them. In a typical 2BHK, internal partitions occupy 20–35 sq ft, so the RERA figure runs 3–6% above what you would measure yourself. Both are correct within their own definitions, and neither is the built-up area, which also adds external walls and the balcony.
Where to find it and why it exists
For any project registered after May 2017, the RERA carpet area appears in the sale agreement, on the state RERA authority's website against the project registration number, and in the developer's advertising. Before the Act, developers used carpet, built-up and super built-up interchangeably and without a common definition, which made two flats impossible to compare. The Act's contribution was a single, statutory definition — not a smaller flat, just an honest number.
The Act also addresses variation. Where the delivered carpet area falls short of the agreed figure, the allottee is entitled to a refund of the proportionate consideration with interest, and an increase beyond a small threshold cannot simply be billed. Measure the flat on possession and compare it with the agreement.
Using it for interior costing
It is a good starting figure, with one adjustment: deduct the internal wall area, because your flooring, your skirting and your furniture do not occupy it. On a 700 sq ft RERA carpet area, working to roughly 670 sq ft gives a more accurate interior estimate. We measure the flat before quoting in any case. See carpet area, the area converter and Mumbai interior costs.
Frequently asked questions
Is RERA carpet area the same as carpet area?+
Almost. RERA includes the area under internal partition walls, which conventional carpet area excludes. The difference is 3–6% in a typical flat — small, but worth knowing when a measured survey does not match the agreement.
Does RERA carpet area include the balcony?+
No. Exclusive balconies, verandahs and open terraces are specifically excluded under Section 2(k), and are usually stated separately in the agreement.
Where can I find my flat's RERA carpet area?+
In the sale agreement, and on the state RERA authority's portal against the project's registration number. For Maharashtra, that is the MahaRERA website, where the registered project's details are public.
Does RERA apply to older buildings?+
The registration requirement applies to projects registered from 2017 onward. For an older flat, the agreement may state built-up or super built-up area, and a physical measurement is the only reliable basis for interior costing.