Is my plot in a Continuous Building Area (CBA)?
In a Continuous Building Area, Rule 35(1)(a) of the Tamil Nadu Combined Development and Building Rules, 2019 (TNCDBR) lets a small building, up to 16 dwellings or 300 sq.m of commercial use and 14 m tall, stand with nil side and rear setbacks. Drop a pin on a Chennai plot and the check says whether it lies inside a mapped CBA, near one (within 50 m), or outside. CBA relaxes the rules, so an in-zone answer is information, not a warning.
Sign in with your phone to run it. You see the price and approve it before anything runs.
- Inside a Continuous Building Area or not, at the pin
- Read as information: CBA relaxes the rules, it does not restrict
- The severe layers (monument buffers, reserve forest, Ramsar wetland, swamp, flood, water bodies, the Redhills catchment) swept at the same pin, shown only if they hit
1 creditper run, charged when the register answers
What we need
One thing at a time. Fill it in and press Run.
The answer
From the register, with its date and source.
Nothing run yet. The answer appears here with everything this mini adds:
- Inside a Continuous Building Area or not, at the pin
- Read as information: CBA relaxes the rules, it does not restrict
- The severe layers (monument buffers, reserve forest, Ramsar wetland, swamp, flood, water bodies, the Redhills catchment) swept at the same pin, shown only if they hit
Continuous Building Area, briefly
CBA (full form: Continuous Building Area) is the dense, already built-up core of Chennai, set apart in the approved Master Plan or Detailed Development Plan, where buildings stand wall to wall along the street and the building rules allow nil side and rear setbacks.
- Setbacks
- Nil side and rear
For small developments (up to 16 dwellings, or commercial up to 300 sq.m) under TNCDBR 2019 Rule 35(1)(a) Table E.
- Height
- 14 m
The CBA height row of the small development table, raised from 12 m by G.O. Ms. No. 69 of 11 March 2024.
- Where
- Chennai only
The Continuous Building Area boundaries are mapped for Chennai. Elsewhere the answer is not covered, which is not the same as outside.
How to check if a plot is in a Continuous Building Area in Chennai
- 1
Place the pin
Tap the plot on the map, paste a Google Maps link to it, or use your location while you stand there.
- 2
Press Run
The survey parcel under the pin is found and the Continuous Building Area boundaries of Chennai are read at that point.
- 3
Read the answer
Inside a CBA (named), near one within 50 m, or outside, with the distance to the nearest CBA. Any severe layer that hits is shown too.
When it helps with land
Narrow old-city plots
In places where houses share walls, the CBA relaxation can decide whether a usable building fits at all.
Before drawing a plan
The architect needs to know which setback table applies before the first sketch. Take the answer to the FSI calculator.
Pricing a small plot
A plot that can be built wall to wall carries more floor area than the same plot outside a CBA.
The relaxation is for small buildings only. Hotels, kalyana mandapams, malls and cinemas still need 6 m all round, and other overlays (heritage, CRZ, airport height) can be stricter. The planning authority's sanctioned plan is what counts. Price: 1 credit per pin, charged only when the layer gives a real answer.
Questions people ask
What is the full form of CBA in Chennai?
CBA stands for Continuous Building Area: the old, densely built core of Chennai, set apart in the approved Master Plan or Detailed Development Plan, where buildings stand in continuous rows along the street.
What is a Continuous Building Area?
It is an area where the Tamil Nadu Combined Development and Building Rules, 2019 allow small buildings without side and rear setbacks. Under Rule 35(1)(a) Table E that covers up to 16 dwellings, or commercial use up to 300 sq.m, up to 14 m tall.
Is being in a CBA a restriction?
No. CBA decides which setback rules apply and relaxes them, so the check reports an in-zone answer as information. It is not a reason to avoid a plot.
Do I still need any open space around the building in a CBA?
Yes. A 1 m internal passage from the rear to the front at ground level is required (Rule 35(1) Explanation 2(v)), and public buildings such as hotels, kalyana mandapams, malls and cinemas need 6 m all round even in a CBA.
What does "near a CBA" mean?
The pin is outside every mapped Continuous Building Area but within 50 m of one. The CBA rules do not apply to it; the answer gives the distance so you know the boundary is close.
Why does it say not covered outside Chennai?
The Continuous Building Area boundaries are mapped for Chennai only. Outside Chennai the layer has no data, so the answer says not covered rather than clear.
How much does it cost?
1 credit per pin, charged only when the layer gives a real answer. A not covered or failed read is not charged. The free finder page stays available for a quick look.