A buyer in Chennai was close to signing for a plot on the city's western edge, drawn by a price noticeably below the approved layouts nearby. The seller called it a CMDA plot and produced a printed layout with plot numbers and roads neatly marked. On a lawyer's prompting, the buyer entered the approval number on the state's planning portal. The number belonged to a different survey and a smaller extent than the plot on offer, and the layout he had been shown was not an approved one at all. The paper looked official. Only the government record showed that the approval it claimed did not cover the land he was about to pay for.

The short answer. Before you buy a plot or flat in Chennai, confirm the planning permission or layout approval on the official Tamil Nadu portal at onlineppa.tn.gov.in, and match the survey number, plot number, extent and road widths on the record against your paperwork. A property inside the metropolitan area needs CMDA approval, and one outside it needs DTCP approval. An unapproved layout can mean refused water and power connections, no home loan, rejected building permission and, under the Town and Country Planning Act, a demolition risk. The trade off is real. Unapproved plots sell for less, but the discount is the price of land the state has not cleared for building.

CMDA or DTCP: which approval should my Chennai property have?

It depends on where the land sits, and one of the two approvals should always be present. The Chennai Metropolitan Development Authority is the planning authority for land inside the Chennai Metropolitan Area, so a plot or project within those limits should carry a CMDA planning permission and layout approval. The Directorate of Town and Country Planning is the state level authority that approves layouts outside the metropolitan area, across the rest of Tamil Nadu. For a buyer the point is not to memorise the boundary but to know that one authority or the other must have approved the layout, and to check which one applies to the survey number you are buying. A seller who cannot say clearly whether the land is a CMDA or a DTCP approval, or who offers only a panchayat or local body number in place of a planning approval, is describing a plot that has not been through the planning process the law requires. That gap is what separates a layout you can build on from one you cannot.

How do I verify a planning permission or layout approval?

You verify it on the state's own planning portal rather than on the seller's printout. The Tamil Nadu online planning permission system at onlineppa.tn.gov.in is where CMDA and DTCP approvals are processed, and you can look an approval up against the number the seller gives you. When a genuine approval is pulled up, the record shows the layout name, the approving office, the plot numbers, the approved extent, the road widths and the open space set aside, and every one of those should match the plot in front of you. Read the survey number, the plot number, the area and the road width on the record against the sale deed and the layout brochure, because a difference in any of them is a verification failure rather than a rounding error. CMDA also publishes lists of unapproved and unauthorised layouts, so it is worth confirming the layout does not appear there. If the number returns a different survey, a smaller extent or another locality, treat the mismatch as the answer, not as a clerical slip to be explained away later.

What is OSR and why does it protect me?

Open space reservation is the share of an approved layout kept aside for public use, and it is a sign of a layout that went through the rules. Under the planning rules an approved layout above a threshold size has to set apart about 10 percent of its extent as open space reservation, and the developer transfers that land to the local body or planning authority through a registered gift deed so that it stays public. Once reserved, OSR land cannot be sold as a plot, built on or converted to private use, and any construction or sale of it is treated as an encroachment on community property under the Town and Country Planning Act. For a buyer this matters in two ways. A layout that shows a properly handed over OSR is one that followed the approval process, and a plot being sold to you that turns out to be OSR land is one you can never lawfully own or build on. The Supreme Court has upheld the rule reserving open spaces, so this is settled ground rather than a technicality a developer can argue around.

What does an approved layout give you that an unapproved one does not?

An approval is not a formality but the thing that makes ordinary ownership possible, and the table below sets out what turns on it.

The discount on an unapproved plot is really a transfer of all these risks to the buyer, priced as if it were a bargain. A cheaper plot that cannot be built on, borrowed against or connected to services is not cheaper in any way that helps a person who wants to live there. That is why the approval check comes before the price talk, not after it.

What are the risks of an unapproved plot or building?

The risks run from everyday inconvenience to the loss of the structure itself. An unapproved layout in Tamil Nadu exposes a buyer to rejected building permission from the local body, refused Metro Water and TNEB connections, and a refusal by banks to lend, which alone rules the plot out for most buyers. Beyond that sits the demolition risk. Construction put up without approval, or on reserved OSR land, can attract a demolition notice under the Town and Country Planning Act of 1971, with the authority empowered to remove the unauthorised structure and restore the land. Resale is the quiet cost that follows, because the next buyer runs the same checks you should have run and walks away for the same reasons. None of these consequences depend on anyone acting in bad faith. They follow automatically from the land never having been approved, which is why the status of the approval, not the intentions of the seller, is what a buyer needs to establish. It is also why a low asking price should raise the question rather than settle it, since the saving on an unapproved plot is exactly the cost of the building permission, the loan and the services that the land cannot yet deliver, and none of that can be recovered by paying less.

What should I verify before buying in Chennai?

Work through these steps before any advance leaves your hands.

1. Establish whether the land falls under CMDA or DTCP based on its location.
2. Get the planning permission or layout approval number from the seller in writing.
3. Verify that number on the official onlineppa.tn.gov.in planning portal.
4. Match the survey number, plot number, extent and road width against your paperwork.
5. Confirm the layout does not appear on the CMDA list of unapproved layouts.
6. Check that the OSR land is marked and handed over, and that your plot is not on it.
7. Resolve any mismatch between the record and the brochure in writing before you commit.

How does this fit the rest of my Chennai checks?

Planning approval is one gate, and it works alongside the title and revenue checks rather than replacing them. An approved layout tells you the land can be built on, while the title trail tells you the seller can actually sell it, which we cover in our guide to reading a mother deed and tracing title. After the sale, the revenue record has to be moved into your name, which is a separate step set out in our explainer on verifying and transferring patta and chitta. Approval, title and patta are three independent checks, and a property has to pass all three. The planning approval is the one that decides whether the land is buildable at all, so it belongs at the start, before you spend effort verifying a title to land you could never construct on.

Frequently asked questions

Where do I verify a CMDA or DTCP approval in Chennai? Use the official Tamil Nadu planning portal at onlineppa.tn.gov.in, where CMDA and DTCP approvals are processed. Enter the approval number the seller provides and check the layout name, approving office, plot numbers, extent and road widths against your paperwork. CMDA also publishes lists of unapproved layouts, so confirm the layout is not named there.

What is the difference between CMDA and DTCP approval? Both are planning approvals, and the difference is location. CMDA approves layouts inside the Chennai Metropolitan Area, while DTCP approves layouts elsewhere in Tamil Nadu, outside the metropolitan limits. One of the two should apply to your plot. A property carrying only a panchayat number, and no planning approval from either authority, has not been through the process.

Can OSR land be sold to me as a plot? No. Open space reservation land is set aside in an approved layout and transferred to the local body through a registered gift deed, so it stays public. It cannot be sold as a plot, built on or converted to private use, and doing so is treated as an encroachment under the Town and Country Planning Act.

What happens if I buy in an unapproved layout? You face rejected building permission, refused Metro Water and TNEB connections and a refusal by banks to lend, and construction without approval can draw a demolition notice under the Town and Country Planning Act of 1971. Resale becomes hard because the next buyer runs the same checks. The low price reflects these risks rather than genuine value.

Last updated 2026-08-31. PropNewz Team.