CMDA and DTCP Approvals: What Chennai Flat Buyers Must Verify

In June 2026 a couple looking at a nearly finished apartment in Ambattur were shown a glossy brochure, a price list and a payment plan, but when they asked for the digitally signed sanctioned plan, the sales team offered only a photocopy with the approval number cut off. A quick check on the state planning portal showed the building had approval for four floors, while five were standing. That fifth floor was the difference between a home loan being sanctioned and the bank walking away. Approvals are not paperwork for its own sake. They decide whether your flat is a secure asset or a dispute waiting to happen, and in Chennai they are one of the first things a careful buyer checks.

The short answer. A Chennai flat needs a valid planning permission, from CMDA inside the Chennai Metropolitan Area or from DTCP and the local planning authority outside it, plus a matching sanctioned building plan and, on completion, an occupancy record. The trade off buyers miss: a cheaper flat in an unapproved or deviated building can cost far more later, because deviations under the Town and Country Planning Act can bring demolition risk, refused utility connections and rejected loans.

Which approval does a Chennai flat need, CMDA or DTCP?

It depends on where the building sits. Inside the Chennai Metropolitan Area, the Chennai Metropolitan Development Authority, or CMDA, grants planning permission for special buildings, generally those of ground plus four floors and above or taller than about fifteen metres, and for multi storeyed buildings. Outside the metropolitan area, the Directorate of Town and Country Planning, or DTCP, works with the local planning authority, and the local body issues the building permit through the same workflow. As a buyer, your first job is to establish which authority had jurisdiction over your building, because the seller should be able to name it and produce the matching permission without hesitation and in a form you can verify independently. If nobody can tell you clearly who approved the building, treat that as a warning sign rather than a technicality. The distinction matters in a practical way too: a special building inside CMDA limits that shows only a small local body permit, and no CMDA planning permission, is a mismatch you should question, because the wrong authority cannot validly approve that class of building. Knowing which authority applies lets you ask for the right document by name instead of accepting whatever paperwork is offered.

Why does an unapproved or deviated building matter to me as a buyer?

Because the risk of an illegal or deviated structure passes to you the moment you buy it. Sellers sometimes add unauthorised floors, build into the mandatory setback space, or exceed the approved floor space index. Each of these is a deviation from the sanctioned plan, and under the Tamil Nadu Town and Country Planning Act of 1971 such violations can expose the building to enforcement action. In practice that can mean difficulty getting or keeping utility connections, trouble obtaining a home loan because banks check approvals, a harder resale later, and in serious cases action against the unauthorised portion of the structure. Regularising a deviation later, where it is even possible, can cost money and time and is never guaranteed. You are not just buying a flat, you are buying its legal status, and a deviation you ignore today becomes your liability tomorrow. This is why banks employ their own technical and legal teams to inspect approvals before sanctioning a loan against a flat. If a lender refuses the property, that refusal is often the clearest signal that something in the approvals does not add up, and it is worth understanding why rather than simply moving to a lender with looser checks. A property that only an informal lender will fund is rarely a bargain.

How do I verify the sanctioned plan for my flat?

You verify it by matching the seller's approval documents against the official planning records and against the building as it actually stands. This is the single most valuable hour of due diligence you can spend. Work through this checklist before you pay any significant advance.

1. Ask the seller or builder for the digitally signed planning permission and the sanctioned building plan.
2. Note the approval number and the issuing authority, whether CMDA or DTCP with the local body.
3. Verify the approval on the official Tamil Nadu online planning permission portal.
4. Count the sanctioned floors and units and compare them with what is physically built.
5. Check that setbacks, height and the number of floors match the approved plan on the ground.
6. Ask for the completion or occupancy record if the building is finished and occupied.
7. Have a property lawyer read the approvals alongside the title documents and the encumbrance record before you commit.

What are the common deviations that sellers do not volunteer?

The most common are an extra floor, encroached setbacks and a higher built up area than sanctioned. An extra floor above the approved count is the classic one, often marketed as a premium unit. Encroachment into the setback, the open space that must be left around a building, is another, and it can block light, ventilation and access for fire safety. Exceeding the approved floor space index means more built area than the plot was permitted, which is a direct violation. None of these will be obvious from a brochure, which is exactly why you compare the sanctioned plan with the real building, floor by floor and boundary by boundary. Take the sanctioned plan with you on a site visit and physically count the floors, look at the open space around the building, and note whether balconies or extra rooms appear to sit outside the approved footprint. If the numbers do not tie out, ask for a written explanation and, if you do not get a clear one, be prepared to walk away. It also helps to speak to existing residents where the building is occupied, because they often know whether the association has faced notices, whether utility connections were delayed, and whether the promised amenities and floors match what was approved. Ground level information like this frequently surfaces problems that no brochure will admit.

Planning permission, building permit and completion: what each document proves

Each document answers a different question, and a careful buyer collects all of them rather than settling for one. The table below sets out what to ask for and what each item confirms, so you can build a simple file for your flat and spot anything that is missing.

What should I insist on before I pay?

Insist on seeing the digitally signed sanctioned plan and independently verifying its number before you part with a large advance. A seller who is confident about approvals will share them readily, while one who stalls, offers only a cropped copy, or promises the completion certificate later is telling you something important. Cross check the approval on the official portal, match the plan to the physical building, and get your lawyer to confirm that the approvals belong to the exact survey number and project you are buying into, not to a neighbouring plot or an earlier phase. Builders occasionally show an approval for one block and sell units in another, so tying the approval to your specific tower and flat is essential. Paying first and verifying later reverses the safe order, and it is the sequence that leaves buyers stuck with a flat a bank will not fund. Keep every approval document, the verified plan printout and your lawyer's note together in one file, because you will need them again when you sell, when you apply for utility connections, and if the housing society ever has to deal with an enforcement query. A clean, complete approval file is also a selling point that can make your own resale faster and smoother, because your future buyer will run exactly the same checks you are running now.

Frequently asked questions

Does a Chennai flat need CMDA or DTCP approval?

It depends on location. Inside the Chennai Metropolitan Area the CMDA grants planning permission for special and multi storeyed buildings. Outside that area the DTCP and the local planning authority handle it and the local body issues the building permit. Ask the seller which authority approved the building and get the matching permission document.

How do I verify a building plan approval in Chennai?

Ask for the digitally signed sanctioned plan and the approval number, then verify it on the official Tamil Nadu online planning permission portal. Compare the sanctioned floors, units and setbacks with the building as it stands. If the seller cannot produce a verifiable approval, treat that as a serious warning and involve a lawyer.

What happens if I buy a flat with an unapproved deviation?

The legal risk moves to you. Deviations from the sanctioned plan can attract enforcement under the Town and Country Planning Act, and in practice they can lead to refused utility connections, difficulty getting a home loan, a harder resale and action against the unauthorised portion. Verifying approvals before you pay is the way to avoid inheriting that risk.

Should the builder give me an occupancy or completion record?

Yes, for a finished and occupied building you should receive the completion or occupancy record from the sanctioning authority. It confirms the building was completed in line with the approved plan and is fit to occupy. If a builder keeps promising it later, press for a firm date in writing and have your lawyer review the position before you commit.

For related Chennai due diligence, see our guide on DTCP and CMDA approved plots in Chennai and on how to verify a project on Tamil Nadu RERA. You can check a sanctioned plan and approval number yourself on the official Tamil Nadu online planning permission portal.

Last updated 2026-09-18. PropNewz Team.