CMDA and DTCP approval in Tamil Nadu: how to check planning permission before you buy

A patta in the seller's name and a price agreed on the guideline value tell a Tamil Nadu buyer nothing about whether the layout or building being sold was ever sanctioned. Planning approval is a separate permission entirely — granted by the Chennai Metropolitan Development Authority (CMDA) inside the Chennai Metropolitan Area, and by the Directorate of Town and Country Planning (DTCP) for the rest of the state — and it is the permission that decides whether a plot can legally exist as a plot and whether a building can legally stand. A parcel with clean revenue records can still sit in an unapproved layout that no authority sanctioned, and a completed flat can still violate the sanctioned plan it was built against. The consequence is concrete: an unapproved layout may be unregularisable and a building that breaches its approved plan can be sealed or demolished. This guide covers what planning approval is, the CMDA-versus-DTCP split, how to verify an approval, what OSR is, and the unapproved-layout risk.

What planning approval is — and how it differs from patta

Planning permission is the sanction, under the Tamil Nadu Town and Country Planning Act, 1971, that a development conforms to the approved land use, road widths, plot sizes, setbacks, open-space norms and civic infrastructure required for the area. It comes in two forms a buyer will encounter. Layout approval sanctions the sub-division of a larger parcel into plots, with the roads and reserved open space marked on an approved layout plan. Planning permission (building) sanctions a specific building against a sanctioned plan showing its footprint, floors, setbacks and use. Both are issued with an approval reference and a stamped, sanctioned drawing.

This is a different permission from every other document a Tamil Nadu buyer checks, and each answers a different question:

• Patta / chitta — who the revenue record shows as the holder of the land, and how the land is classified. It says nothing about whether a layout or building on that land was sanctioned.
• Encumbrance certificate — what has been registered against the property: sales, mortgages, attachments. It records transactions, not planning approval.
• Guideline value — the government floor on which stamp duty is computed. A cost figure, not an approval.
• Planning approval (CMDA / DTCP) — whether the layout or building was legally sanctioned to exist. This is the leg the other three do not cover.
• Completion / occupancy — a further step confirming the building was actually finished in line with the sanctioned plan. Approval to build is not proof of lawful completion.

CMDA vs DTCP — which authority approves where

Tamil Nadu splits planning-approval jurisdiction geographically, and the first thing a buyer must establish is which authority should have sanctioned the property. Approval from the wrong authority — or from a local body that had no power to grant it — is as much a defect as no approval at all.

• CMDA — the Chennai Metropolitan Development Authority is the planning authority for the Chennai Metropolitan Area, which covers the Greater Chennai Corporation together with the surrounding municipalities, town panchayats and villages that make up the metropolitan region. A layout or building within these limits is sanctioned by CMDA (with the local body executing lower-order permissions).
• DTCP — the Directorate of Town and Country Planning is the planning authority for the rest of Tamil Nadu outside the Chennai Metropolitan Area, working through its regional and local planning authorities. Plotted developments marketed across the state as 'DTCP-approved plots' fall under this arm.

Both operate under the same statute — the Tamil Nadu Town and Country Planning Act, 1971 — and both now route applications through the state's single-window planning portal. So the question at diligence is not merely 'is there an approval', but 'is there an approval from the authority with jurisdiction over this exact location'. Fringe parcels near the metropolitan boundary are where this most often goes wrong.

How to verify a CMDA or DTCP approval — step by step

Verification means matching a claimed approval to the authority's own record and reconciling the sanctioned plan against the plot on the ground. Ask the seller for the approval reference and the stamped, sanctioned layout or building plan first — a genuine approval has both.

1. Establish jurisdiction — confirm from the address whether the property is inside the Chennai Metropolitan Area (CMDA) or elsewhere in the state (DTCP). This determines which authority's approval you should be seeing.
2. Get the approval reference and sanctioned plan — obtain from the seller the planning-permission or layout-approval number and the stamped sanctioned drawing, not a marketing site plan.
3. Verify against the authority's record — check the approval on the Tamil Nadu single-window planning portal (onlineppa.tn.gov.in) and, for Chennai, against CMDA's published planning-permission approval details on its official site. Confirm the reference, the approved use and the sanctioned plot or building configuration.
4. Reconcile the plan with the ground — check that the plot number, extent, road widths and reserved open space on the approved layout match what is being sold and what exists on site. A building must match its sanctioned plan in footprint, floors and setbacks; extra floors or coverage beyond the sanction is a violation.
5. Check the OSR handover — for a layout, confirm the Open Space Reservation land has been handed to the local body (see below) and is unfenced and accessible on site, not quietly sold as a plot.
6. Cross-check with revenue and registration records — reconcile the approval against the patta, the encumbrance certificate and the registered gift deeds for the layout's roads and OSR, so the planning and title pictures agree.

OSR — the open space that has to be handed over

Open Space Reservation (OSR) is the land an approved layout must set aside for public amenities — parks, playgrounds and recreational space. Under the Tamil Nadu development rules, a layout above the prescribed threshold has to reserve a portion of its area (commonly 10% for larger layouts) as OSR and hand it to the local body, typically through a registered gift deed, so it belongs to the public and cannot be sold as a plot. OSR matters to a buyer for two reasons: its presence is a marker of a genuine, approved layout, and its absence or diversion is a marker of an unapproved or manipulated one.

The recurring trap is the layout that shows OSR on its approved plan but where the reserved land has been fenced off, encroached, or quietly sold as an extra plot. Ask the local body for the OSR handover confirmation, check the registered gift deeds for the OSR and internal roads on the encumbrance certificate, and confirm on site that the reserved open space actually exists and is accessible. An OSR parcel that has been converted into a saleable plot is a sign the layout is not what its paperwork claims.

The unapproved-layout risk, and the limits of regularisation

An unapproved layout is one sub-divided and sold as plots without any planning authority sanctioning it. It is common precisely because it is cheaper for the seller — no approval process, no OSR to surrender, no infrastructure standards to meet. For the buyer, the costs land later. An unapproved plot can be refused a building-plan approval, denied a water or electricity connection, blocked from bank finance, and left unregularisable if it fails the eligibility for any regularisation scheme. A building that breaches its sanctioned plan carries its own exposure — the unauthorised portion, or the whole structure, can be sealed or ordered demolished.

Tamil Nadu has run paid schemes to regularise eligible unapproved plots — most notably the Regularisation of Unapproved Plots and Layouts Rules, 2017, framed under Section 113-C of the Town and Country Planning Act, 1971, which allowed eligible plots created before a cut-off date to be regularised on payment. But regularisation is not a cure a buyer should rely on. It is eligibility-bound: a plot may not qualify at all, the scheme may not be open when needed, and even a regularised plot can attract charges and conditions the original approval would have avoided. Buying an unapproved plot on the assumption it can simply be regularised later is a bet on a scheme that may not apply.

A verification checklist before you pay

• Identify the authority — confirm from the address whether the property falls under CMDA (Chennai Metropolitan Area) or DTCP (rest of Tamil Nadu), and that the approval you are shown is from that authority.
• Get the approval reference and the stamped sanctioned plan — not a brochure site plan — and verify the reference on the official single-window and CMDA / DTCP portals.
• Match plan to ground — confirm the plot number, extent, road widths, setbacks and building configuration on the approved plan match what is being sold and what exists on site.
• Confirm OSR handover — check the OSR land is gifted to the local body, recorded on the encumbrance certificate, and physically present and accessible, not sold off.
• For a building, confirm it matches its sanctioned plan and, separately, that completion / occupancy is in order — approval to build is not proof of lawful completion.
• Do not rely on future regularisation — verify a specific unapproved plot's eligibility in writing with the planning authority before, not after, buying.
• Run the patta, chitta, FMB, guideline value and a long-period encumbrance certificate in parallel — planning approval is one leg of the check, not the whole of it.
• Have a property advocate examine the approval, sanctioned plan, revenue records and title chain together before any payment.

SourceTamil Nadu Single Window Portal for Planning Permission (CMDA and DTCP online planning applications)

SourceChennai Metropolitan Development Authority (CMDA) — official website (planning permission and approval details)

SourceDirectorate of Town and Country Planning (DTCP), Government of Tamil Nadu — official website (rules, approved layouts, regularisation)

SourcePropWatch — Patta and Chitta in Tamil Nadu: how to check, verify and download a land record online

SourcePropWatch — Guideline value and stamp duty in Tamil Nadu: how to check before you register

SourcePropWatch — Chennai real estate legal & TNRERA report