CMDA Chennai 2026: Planning Permission, Approved Layouts and Expansion

Posted by Housepartner Editorial Team on 09/11/2026

Housepartner Editorial TeamUpdated 9 Nov 2026 · 7 min read

Checked against official government sources. General information, not legal or financial advice.

The Chennai Metropolitan Development Authority (CMDA) is the Tamil Nadu government body that plans the Chennai Metropolitan Area (CMA) and grants planning permission for layouts and larger buildings there. It works under the Tamil Nadu Town and Country Planning Act, 1971, and its official website is cmdachennai.gov.in. Applications are filed online through the Tamil Nadu Single Window Portal (onlineppa.tn.gov.in). This guide covers what CMDA does, the planned CMA expansion, online approvals and how to check a layout before you buy.

CMDA at a glance

Set up: 1972 as an ad hoc body; statutory since 1974 under the Tamil Nadu Town and Country Planning Act, 1971
Official website: cmdachennai.gov.in
Apply online: Tamil Nadu Single Window Portal, onlineppa.tn.gov.in
Office: Thalamuthu-Natarajan Building, No. 1, Gandhi Irwin Road, Egmore, Chennai – 600008; phone 044-28414855
Current CMA: 1,189 sq km; expansion to about 5,904 sq km approved, with work under way to bring it in
Master plan: Second Master Plan 2006–2026; Third Master Plan now expected in 2027, as reported
Small homes: instant self-certified permit for homes up to 3,500 sq ft built-up; a rise to 5,000 sq ft was announced in August 2026

In this guide

What does CMDA do?
Chennai Metropolitan Area and the expansion
Master plans
Planning permission online
Regularisation of unapproved plots
How to check if a layout or building is CMDA approved
Before you buy in the Chennai region
Frequently asked questions

What does CMDA do?

Planning: prepares the master plan and detailed development plans that fix land use across the CMA.
Planning permission: approves layouts, sub-divisions, special and multi-storeyed buildings and change of land use.
Delegation: smaller buildings are approved by local bodies such as the Greater Chennai Corporation under powers delegated by CMDA.
Projects: works such as bus termini, new town plans and road grids for growth areas.
Enforcement: action against unauthorised construction.

Chennai Metropolitan Area and the expansion

The CMA has been 1,189 sq km since 1972. In 2022 the state ordered its expansion to about 5,904 sq km, adding areas of Kancheepuram, Tiruvallur, Chengalpattu and Ranipet districts, including Arakkonam taluk. CMDA’s 2024–25 policy note describes the CMA as extended to 5,904 sq km. As reported in October 2026, the state has started steps to bring the new areas into CMDA’s planning work, and the Third Master Plan will now cover them too.

In practice, approvals in some newly added areas may still go through the Directorate of Town and Country Planning (DTCP) or the local body. Before you buy, check which authority approves plans for your village.

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Master plans

Plan	Period	Status (Nov 2026)
Second Master Plan	2006–2026	In force for the 1,189 sq km area
Third Master Plan	2027–2046	Being prepared; first targeted for January 2026, now expected in 2027, as reported
New town development plans	2025–2045	Under way for Thirumazhisai, Mamallapuram, Kancheepuram and Chengalpattu

The land use zone of your plot in the master plan (primary residential, mixed residential, commercial, industrial, agricultural and so on) decides what can be built. Check it before you buy.

Planning permission online

CMDA moved to a fully online Planning Permission Application system in May 2022. Since 17 November 2023, layout applications are taken only online.

Engage an architect or engineer registered with CMDA or the local body. Most applications are filed by them.
Apply on the Tamil Nadu Single Window Portal (onlineppa.tn.gov.in) with ownership documents, the encumbrance certificate, drawings and site photos.
The portal checks drawings, ownership papers, the encumbrance certificate and guideline value. It is linked with NOC-issuing departments, so NOCs can be sought in the same flow.
Pay the scrutiny fee and other charges online when demanded.
Track the status online and download the planning permission once issued.

CMDA’s policy note says approvals take 30 to 60 days, with a target of 30 days. Local bodies handle smaller buildings (under 10,000 sq ft and up to 14 m height, as per the 2024–25 policy note) through the same portal. In August 2026 the state announced higher limits for corporations and municipalities, up to 16,140 sq ft for residential buildings; check the current limit on the portal.

Self-certified permit for small homes

Since July 2024, Tamil Nadu gives an instant building permit on self-certification through onlineppa.tn.gov.in for residential buildings on plots up to 2,500 sq ft with built-up area up to 3,500 sq ft. It started with ground or ground plus one floor up to 7 m, and from 3 September 2025 also covers stilt plus two floors up to 10 m. In August 2026 the state announced a rise to 5,000 sq ft for ground plus two and stilt plus three homes; wait for the government order and portal update before relying on it. The permit carries a QR code and is valid for five years. It is cancelled if the land turns out to be government land, open space reserve or a water body.

Regularisation of unapproved plots

Owners of plots in unapproved layouts bought before 20 October 2016 can apply for regularisation under the Tamil Nadu Regularisation of Unapproved Layouts and Plots Rules, 2017. As reported in June 2025, the state removed the time limit, so applications can be made even after 30 June 2026. Applications are online only. The charge under the 2017 rules is ₹100 per sq m in corporation areas, ₹60 in municipal areas and ₹30 in village and town panchayats, plus other charges as applicable.

How to check if a layout or building is CMDA approved

Ask the seller for the CMDA planning permission letter, the approval number and the approved layout or building plan.
Check the approval on the Single Window Portal or with CMDA at Egmore using that number.
Match the survey number, village, plot number, extent and road width with the approved plan.
Check that your plot is not part of the open space reserve (OSR) or a road shown on the plan.
For a regularised plot, ask for the regularisation order.
Check patta and chitta, the FMB sketch and the encumbrance certificate on TNREGINET.

Before you buy in the Chennai region

Confirm whether CMDA, DTCP or the local body is the approving authority.
For a flat or plotted project, check TNRERA registration.
Know the guideline value in Chennai and stamp duty in Tamil Nadu before you register.
For a finished building, ask for the completion or occupancy certificate.

Frequently asked questions

What is the full form of CMDA?

Chennai Metropolitan Development Authority. It plans the Chennai Metropolitan Area under the Tamil Nadu Town and Country Planning Act, 1971.

What is the area of the Chennai Metropolitan Area?

It has been 1,189 sq km. The state has approved expanding it to about 5,904 sq km, and as of late 2026 CMDA is bringing the new areas into its planning work.

How do I apply for CMDA planning permission?

Apply online on the Tamil Nadu Single Window Portal (onlineppa.tn.gov.in), usually through a registered architect or engineer, with ownership papers, the encumbrance certificate and drawings.

How do I check if a plot is CMDA approved?

Get the planning permission letter and approval number from the seller, check it on the portal or at CMDA, and match the survey and plot numbers with the approved layout plan.

What is the difference between CMDA and DTCP approval?

CMDA approves layouts and buildings inside the Chennai Metropolitan Area. DTCP approves them in the rest of Tamil Nadu outside other planning authorities. Both are valid approvals for their own areas.

Can I build a small house without waiting for approval?

For homes up to 3,500 sq ft built-up on plots up to 2,500 sq ft, you can get an instant self-certified permit on onlineppa.tn.gov.in, within the floor and height limits. A rise to 5,000 sq ft announced in August 2026 awaits its government order.

When will Chennai’s Third Master Plan come out?

It was first targeted for January 2026. As reported in October 2026, CMDA now expects it in 2027.

Planning rules, fees and jurisdiction are set by CMDA and the Government of Tamil Nadu and can change. Check the current position on cmdachennai.gov.in, the Single Window Portal or at the CMDA office before you buy or apply. This guide is general information, not legal advice. Sources: CMDA official website and RTI handbook; Housing and Urban Development Department policy note on CMDA 2024–25; Tamil Nadu Single Window Portal; Tamil Nadu Regularisation of Unapproved Layouts and Plots Rules, 2017; 2024–2026 reports in DT Next and ThePrint, including G.O.(Ms) No.118 of 2025 as reported.

About the author

Housepartner Editorial Team Housepartner.in

The Housepartner Editorial Team writes and reviews Housepartner's buyer guides on RERA, land records, stamp duty and property documents, using official government sources. The team has worked in Indian real estate since 2013.

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