In this guide — 6 sections
Nine steps: verify zone and jurisdiction; appoint a COA-registered architect; gather owner documents; prepare drawings; submit online via CMDA OSW or TNOBPAS; technical scrutiny; site inspection; respond to objections; and receive the approval order with the sanctioned plan. Expect 30–45 working days for a clean residential submission, and 60–90 with one round of objections.
CMDA approval is where most home construction projects lose time they never planned for — almost always to something that was avoidable at the first submission.
Which Authority approves your building
Which authority covers your plotThis single determination drives every subsequent action — settle it before any drawing is prepared.
The CMA was expanded in October 2022 to include contiguous areas across 1,225 additional villages. If your plot is in a peri-urban area on the fringe — Chengalpet, Kanchipuram district, Thiruvallur — confirm current CMA inclusion with a COA-registered architect before choosing your application channel. Getting this wrong means filing with the wrong body and starting over. Source: CMDA official website and the October 2022 CMA expansion notification.
Who needs Planning Permission
Within the CMA, you need it for any of the following: constructing a new residential building of any kind; adding one or more floors; making a horizontal extension that increases built-up area; demolishing and rebuilding on the same plot; changing the use of a building; or laying out land into plots.
There is no minimum size exemption. Even a simple single-storey ground-floor house requires building plan approval from the appropriate local body. Only minor internal alterations that do not affect built-up area or the structural system typically fall outside the requirement — and ‘typically’ is doing real work in that sentence, so confirm rather than assume.
Nine Steps from zone check to sanctioned plan
Nine steps to approval
Two are highlighted — they decide the timelineVerify site zone and jurisdictionBefore design
Your architect confirms six things before a single drawing exists:
- Whether the plot falls within the CMA under CMDA or GCC, or outside it under DTCP
- The land use zone under the Chennai Master Plan — residential, commercial, agricultural
- Applicable FSI for your zone and road width
- Minimum setbacks — front, rear and side — based on plot area and road width
- CRZ applicability if on or near the coast, including ECR and the Kovalam area
- Airport height restrictions from AAI if near Chennai airport
Appoint a COA-registered architect
Only an architect registered with the Council of Architecture and licensed by CMDA can sign and submit building plan applications. They prepare all drawings compliant with the Development Control Regulations, certify conformity, digitally sign everything with a Class 3 DSC, and submit and track the application on your behalf.
Gather owner documents
Nine documents must be ready before submission — set out in full in the checklist below. The one that most often causes trouble is the Patta, which must be current within three months at the time of submission, not at the time you started planning.
Prepare architectural and structural drawingsThe core technical work
A complete package: site plan at 1:200 or 1:500, key plan, floor plans at 1:100, all four elevations, longitudinal and cross-sections, area statement, rainwater harvesting pit drawing, structural stability certificate, and parking layout where applicable. The structural certificate is signed by a licensed structural engineer — separate from the architect’s certification.
Submit online via CMDA OSW or TNOBPAS
Most applications now go through the CMDA Online Single Window system or the TNOBPAS portal, in five stages:
- Register on the portal using your mobile number — or the GCC building plan portal if submitting through that channel
- Create the application with survey number, location, zone classification and proposed building parameters
- Upload drawings and documents — drawings as DWF or PDF carrying the architect’s digital signature, owner documents as scanned PDFs
- Pay fees online. The portal calculates them automatically from built-up area, zone and building type
- Receive a docket number and track scrutiny status online without visiting the office
Technical scrutiny
An officer reviews the drawings against eight compliance parameters: FSI, setbacks, building height against zone and AAI limits, parking provision, staircase and corridor widths per NBC 2016, rainwater harvesting provision, land use conformity, and drawing scale accuracy — the dimensions in the area statement must match the plan drawings.
Site inspection
An assistant planner may visit to verify that the drawings match ground reality — plot dimensions, existing structures, road width and access. For ordinary residential applications this often happens concurrently with scrutiny. Ensure the plot is accessible and boundary markers are clearly visible.
Respond to objectionsWhere timelines slip
If the officer raises technical objections, you receive a formal notice. Four things to know:
- Responses are typically required within 30 days of the notice date
- Each round of objections and resubmission adds roughly 15–30 days to the total
- More than two rounds significantly delays approval and may trigger re-scrutiny fees
- A well-prepared first submission, pre-checked against every compliance parameter, eliminates most objections before they arise
Approval order and sanctioned plan
Once scrutiny is complete you receive the Approval Order granting Planning Permission, the sanctioned drawing set — stamped and signed, and your legal construction reference — and an approval letter listing ongoing conditions such as the three-year construction start requirement.
Steps 1 and 8 are highlighted because they are the same problem seen from two ends. Everything an officer objects to at step 8 — FSI, setbacks, land use, parking — was knowable at step 1, before a line was drawn. The work done in the first fortnight is what determines whether the process takes forty-five days or ninety.
Our COA-registered architects hold Class 3 DSC tokens and have processed approvals across the city. We also produce elevation drawings for approval and 3D renderings as part of the pre-approval package.
Fee Components and realistic timelines
What you pay for
Total cost is government statutory fees plus the professional architect fee. The components:
- Development Charge — varies by zone and built-up area.
- Scrutiny Fee — charged per square metre, with commercial rated higher than residential.
- Refundable Security Deposit — fully refunded after the Completion Certificate is obtained. This is the single largest component for most homeowners, and it is recoverable.
- Infrastructure and amenity charges — higher for commercial than residential.
- Self-certification charges for small houses within GCC limits, and a separate lower rate for peri-urban village panchayats within CMDA limits, both per the Tamil Nadu GO of August 2024.
- Premium FSI Charge — applicable only when exceeding base FSI, and priced per square metre by zone.
- Architect fee — for the full drawing package and online submission management, varying with scope, building size and complexity.
First: fees are revised periodically. Always verify the current schedule of charges directly on the CMDA official website or the GCC portal before finalising your budget — any figure quoted in an article, including this one, is a snapshot.
Second: the security deposit comes back. It is returned in full after you obtain the Completion Certificate, so it belongs in your cash flow plan rather than your cost estimate. Apply proactively with completion photographs and inspection clearance — the refund typically takes 60–90 days from application, and nobody chases it on your behalf.
Realistic timelines
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| Application type | Expected timeline |
|---|---|
| Standard residential G+2, clean first submission | 30–45 working days from submission |
| Standard residential G+2, one round of objections | 60–90 working days total |
| Special building G+3, direct CMDA application | 45–90 working days under CMDA direct scrutiny |
| Special building with high-rise NOCs and multiple rounds | 3–6 months or longer |
| Application with outdated Patta or missing documents | Rejection and restart — adds 4–8 weeks minimum |
| Layout or land sub-division application | 3–6 months depending on size and location |
These are working days, and the distinction matters more here than it sounds. Tamil Nadu has multiple gazette holidays, local body holidays and event closures that meaningfully extend calendar timelines. Plan your construction start with a 30-day buffer beyond the expected approval date — and note that the outdated-Patta row is the only one on this list that adds weeks for a reason entirely within your control.
Everything an Officer Objects To Was Knowable Before a Line Was Drawn
FSI, setbacks, land use and parking are all confirmable at the zone-check stage — which is what separates a forty-five day approval from a ninety day one.
Nine Rejection Reasons, all avoidable
Rejection against objection
These are different events and the distinction is worth holding onto. An objection notice is a request for clarification or correction within the existing application — it does not restart the clock. A rejection is a formal refusal, and the response depends on why:
- Rejected for technical reasons: your architect revises the drawings to address the stated grounds and files afresh. A fresh application incurs new scrutiny fees.
- Rejected for land-use reasons: the construction type must change to match the zone designation, or a formal land-use change application is required — a considerably longer process.
- Rejected for document deficiencies: gather what is missing and file afresh once complete.
Building without approval
Constructing without Planning Permission within the CMA is illegal under the Tamil Nadu Town and Country Planning Act, 1971. Five consequences follow:
- Demolition order — CMDA and the local body can issue a demolition notice for any unauthorised structure
- Stop-work notice — construction in progress can be halted by an officer on site
- No utility connections — banks, TANGEDCO, CMWSSB and the registration authority will not process connections or registration without a valid approval order
- Legal liability — the building cannot be sold, mortgaged or registered
- Fines and compounding fees — regularisation is sometimes possible but not guaranteed, and involves significant cost
What Happens after approval
Receiving your sanctioned plan is the starting line, not the finish. Six obligations follow:
- Display the approval order on siteA legal requirement throughout the construction period.
- Construct strictly as per the sanctioned drawingsAny deviation in room positions, floor heights or built-up area is a violation.
- Begin construction within 3 yearsIf work does not start within three years of the approval date, the approval expires and you must re-apply.
- Obtain a Plinth Level CertificateFrom the relevant authority before the slab is cast, where required.
- Apply for the Completion CertificateAfter construction is complete. Mandatory for utility connections and property registration.
- Claim your Security Deposit refundOnce the Completion Certificate is granted — applying proactively with photographs and inspection report.
Items 5 and 6 are connected, and both are commonly left undone. The Completion Certificate is what unlocks utility connections and registration — and it is also the precondition for getting your security deposit back. A homeowner who skips it forfeits the deposit and holds a property that cannot be cleanly registered, which is an expensive way to save an afternoon of paperwork.
Once the structure is approved and under construction, interior planning can begin in parallel — saving time between shell completion and possession.
Preparation checklist
Work through this before your architect submits. Seven owner documents, ten technical items, four submission checks.
Swipe or scroll to see the full table →
| Check | Before submission |
|---|---|
| [Owner] Current Patta — updated within 3 months of the submission date | |
| [Owner] Registered Sale Deed or Title Deed, including all parent documents | |
| [Owner] Encumbrance Certificate covering a minimum 15-year period | |
| [Owner] FMB or Survey Sketch from the Taluk or Survey Department | |
| [Owner] Latest property tax receipt for GCC applications | |
| [Owner] NOC from TNHB or CMDA if the plot was allotted by a housing board | |
| [Owner] AAI NOC if the plot sits in the airport height funnel zone | |
| [Technical] Site plan at 1:200 or 1:500 with north point, road width and setback lines | |
| [Technical] Key plan locating the site within the neighbourhood | |
| [Technical] Floor plans of all levels at 1:100 with room dimensions and areas | |
| [Technical] All four elevation drawings showing building height | |
| [Technical] Longitudinal and cross-section drawings | |
| [Technical] Area statement — FSI calculation verified against the zone permissible limit | |
| [Technical] Rainwater harvesting pit shown in plans with capacity | |
| [Technical] Parking layout, if applicable to your built-up area | |
| [Technical] Structural Stability Certificate signed by a licensed structural engineer | |
| [Technical] Digital signature of the COA-registered architect on all drawings | |
| [Submission] Application channel confirmed — GCC for ordinary residential, CMDA direct for special or high-rise | |
| [Submission] All documents scanned and uploaded as PDF or DWF | |
| [Submission] Fees calculated and payment ready — government plus consultant | |
| [Submission] Docket number received and tracking started |
Only If You Apply for the Completion Certificate
It unlocks utility connections, property registration and your refund — and nobody initiates it on your behalf. Allow 60 to 90 days from application.
There is no legal shortcut. Planning Permission must be obtained before the first footing is cast.
— The Tamil Nadu Town and Country Planning Act, 1971
Frequently Asked Questions
Who needs CMDA approval?
Anyone constructing a new building, adding floors, extending built-up area, demolishing and rebuilding, changing a building’s use, or sub-dividing land within the CMA. There is no minimum size exemption — even a single-storey ground-floor house requires approval from the appropriate local body.
What documents are required?
Current Patta updated within three months, registered Sale Deed with parent documents, a 15-year Encumbrance Certificate, FMB or survey sketch, latest property tax receipt for GCC applications, and where applicable an NOC from TNHB or CMDA, an AAI NOC for airport height funnel zones, and a Power of Attorney if a representative is filing.
How long does approval take?
30–45 working days for a standard residential G+2 with a clean first submission, and 60–90 working days with one round of objections. Special buildings take 45–90 working days, and layout applications 3–6 months. These are working days — allow a 30-day buffer for gazette and local body holidays.
How much does approval cost?
Government statutory fees comprise development charge, scrutiny fee, refundable security deposit, infrastructure and amenity charges, and premium FSI charge where base FSI is exceeded. The architect fee is separate. Fees are revised periodically — verify the current schedule on the CMDA or GCC portal before budgeting, and remember the security deposit is fully refundable.
Can I construct without approval?
No. It is illegal under the Tamil Nadu Town and Country Planning Act, 1971. Consequences include a demolition order, stop-work notice, refusal of utility connections by TANGEDCO and CMWSSB, inability to sell mortgage or register the property, and fines. Regularisation through compounding fees is sometimes possible but not guaranteed.
What is the difference between planning permission and building permission?
Planning Permission is the land-use and development approval granted under the planning framework — confirming the proposed building conforms to the Master Plan zone, FSI and setback norms. Building permission is issued by the local body for the construction itself. In practice for a residential application both are handled through the same submission channel.
What happens if my application is rejected?
It depends on the ground. Technical rejections mean revising drawings and filing afresh, which incurs new scrutiny fees. Land-use rejections require changing the construction type to match the zone, or a formal land-use change application. Document deficiencies mean gathering what is missing and refiling. An objection notice is different — it does not restart the clock.
How long is approval valid?
Construction must begin within three years of the approval date. If work does not start within that window the approval expires and you must apply again — which means fresh fees and fresh scrutiny against whatever the regulations say at that point rather than at original approval.
Can I change the design after approval?
Construction must follow the sanctioned drawings strictly. Any deviation in room positions, floor heights or built-up area is a violation. Where a change is genuinely necessary, it must go back through the approving authority as a revised application rather than being executed on site and regularised later.
What is the Completion Certificate and do I need it?
It is issued by the approving authority after construction is complete, and it is mandatory for utility connections and property registration. It is also the precondition for your refundable security deposit — apply proactively with completion photographs and inspection clearance, and allow 60–90 days from application for the refund.
Zone Check, Drawings, Filing and Objection Response
COA-registered architects with Class 3 DSC tokens, a complete pre-checked drawing package, and the compliance work done at step one rather than discovered at step eight.
Plan right, build legal
CMDA approval is a nine-step process where almost all the risk sits in the first two weeks. Building plan approval that clears on the first submission is not luck — it is a zone check done properly, a Patta ordered at the right moment, and an area statement whose numbers match the drawings. Contact Buildiyo for approval support on your project.