CMDA building plan approval in Chennai — end-to-end

What CMDA approval is — and who needs it

The Chennai Metropolitan Development Authority (CMDA) regulates building construction inside the Chennai Metropolitan Area — roughly the 1,189 sq km that covers most of inner Chennai. Any new building, vertical addition, or major modification inside this zone requires written approval before construction begins. Building without approval is technically illegal, attracts penalties, blocks utility connections, kills resale value and exposes you to demolition orders.

Areas outside CMDA limits — much of Chengalpattu, Tiruvallur, Kanchipuram, the outskirts — fall under DTCP (Directorate of Town and Country Planning), Panchayat or Corporation jurisdictions, each with their own approval process. The first step in any Chennai project is confirming which authority your plot falls under.

• You need CMDA approval if — you're building a new house, adding a floor, doing major civil modifications, or converting use (e.g. residential to commercial) inside CMDA limits.
• You probably don't need CMDA — for minor internal renovation, plumbing/electrical work without structural change, painting, false ceiling, modular kitchen / wardrobe fit-out.
• You need a different authority — if your plot is in DTCP, Panchayat or Corporation jurisdiction (Homeli handles all of these too).

2026 CMDA charges — the real breakdown

CMDA approval involves four cost buckets. Most homeowners only see the bottom-line number and don't realise how it splits. Here are the 2026 ranges for a typical residential project (1,500–2,500 sq ft built-up):

Bottom line for a typical 1,500 sq ft residential home in 2026: roughly ₹60,000–₹1,40,000 total — of which ~₹40,000–₹80,000 is the refundable security deposit you get back at completion. The non-refundable portion is usually ₹20,000–₹60,000.

The 7-stage approval process

Homeli handles all seven stages so you don't have to deal with the CMDA office directly. Here is how the timeline plays out for a typical residential approval:

1. Site visit + jurisdiction check — confirm CMDA vs DTCP, measure plot, verify setback rules apply, note neighbour-side constraints. Day 1.
2. Drawings preparation — architectural floor plans, elevation, section, site plan, structural drawings, all signed by registered architect + structural engineer. Days 2–14.
3. Document compilation — patta, EC, tax receipts, title deed, ID proofs, affidavit, application form. We assemble and verify completeness. Days 14–18.
4. Online filing — submission through the CMDA OSR (Online Single Window) portal, with all drawings and documents uploaded. Fees calculated automatically. Day 18–20.
5. Fee payment — development charges + scrutiny + security deposit paid online via the portal. Same day.
6. Site verification — CMDA assistant planner visits the plot to confirm submitted drawings match ground reality. Days 20–35.
7. Approval issued (or objections to address) — if everything is in order, the sanctioned plan is issued. If there are queries — setback adjustment, missing document, FSI clarification — we address them and resubmit. Days 35–45.

Documents you must keep ready

CMDA filing fails most often because of missing or stale documents. Get all of these together before we file:

• Patta (land record) — original + photocopy. Must show the current owner's name. Out-of-date patta needs to be updated at the taluk office first.
• Title deed — sale deed / gift deed / will, whatever transferred ownership to the current holder.
• Encumbrance Certificate (EC) — latest, covering at least the last 15 years. From the sub-registrar office or online via TNREGINET.
• Latest property tax receipt — current year, paid to Corporation / Municipality.
• ID proof of owner — Aadhaar + PAN.
• Survey / FMB sketch — field measurement book sketch showing the plot boundaries.
• Affidavit + application form — Homeli prepares both; you sign.
• Architect's drawings — site plan, floor plans, elevation, section, structural drawings — all signed.
• Power of attorney — only if someone other than the owner is filing on the owner's behalf.
• NOC (case-specific) — fire NOC for larger buildings, airport authority NOC for plots near flight paths, coastal regulation NOC for plots inside CRZ.

If any of these is missing or out of date, that's the first thing we fix — usually within a week. Filing with incomplete documents almost guarantees an objection cycle.

Common rejection / objection reasons (and how we prevent them)

After 400+ Chennai approvals, the same handful of issues cause 80% of objections. Here is what they are and how we pre-empt them:

• Setback violation — front, rear or side setbacks not meeting CMDA norms for the zone. Prevented by measuring the plot and verifying setbacks before designing.
• FSI exceeded — proposed built area exceeds the FSI allowed for the plot's zone (residential zones typically allow 1.5–2.0 FSI). Prevented by calculating allowable built area first, designing within it.
• Encroachment on right-of-way — building on or near a designated road widening line. We check the master plan before designing.
• Patta vs ground mismatch — patta shows one boundary, ground survey shows another. We get this reconciled before filing.
• Missing structural certificate — building above ground floor needs a stability certificate from a registered structural engineer. Bundled with our drawings.
• Affidavit errors — wrong format, missing signature, stale stamp paper. Standard affidavit format used and re-checked.
• Stale documents — EC older than 30 days, tax receipt over a year old. We refresh before submission.

See also: DTCP approval (outside CMDA areas), Panchayat approval, architectural services, structural drawings.

Frequently asked