Demolishing an old house in Kolkata doesn’t mean a new one can cover the same ground. Kolkata Municipal Corporation’s Building Rules, 2009 cap how much of a plot a structure may occupy, how far it must sit from every boundary, and how much total floor area the road width out front allows — three separate limits that apply together no matter how the previous building sat on the plot, common walls included.
This page works through all three using the actual KMC rule tables: ground coverage by plot size, Rule 62 setbacks by building height, and Floor Area Ratio and maximum height by road width.
Enter your own plot width, depth and road width to see the buildable footprint and the open land a 3, 3.5 or 4 cottah plot is left with once rebuilding rules apply.
How much land do you have to leave when you rebuild?
A companion to the demolition cost assessment — focused specifically on what happens after the old house comes down. Ground coverage, setbacks and road-width-linked FAR limits mean a rebuild almost never fills the old footprint, even if the original house had no front/side open space at all.
Do you lose land when you rebuild?
So with this research in mind, I have a follow-up question: when you demolish these old buildings, do you still cover the entire plot — nothing on the front, nothing on the sides, even where adjacent buildings had common walls? In today’s rules, do you have to leave setback spaces? In KMC areas, how much area do you lose — or rather, how much space do you have to leave — when you demolish and build a new building?
Short answer: no, you can’t rebuild across 100% of the plot
Even if the old G+2 house occupied virtually the whole plot with common walls on the sides, a replacement building is bound by three independent limits: ground coverage (how much of the plot the footprint may occupy), setbacks (open space KMC requires on every side, from Rule 62), and FAR (total floor area across all storeys, linked to road width). The figures below were checked against the actual KMC Building Rules, 2009 Gazette text — most widely-cited numbers matched exactly; a couple of frequently-circulated figures could not be independently confirmed and are flagged below. Each rule below has its own quick calculator — the full visualizer right after combines all three for your actual plot.
| Plot size | Area | Coverage (base 2009 rule) | Max footprint | Open land |
|---|---|---|---|---|
| 3 cottahs | 2,160 sq ft (200.7 m²) | ≈59.8% | ≈1,291 sq ft | ≈869 sq ft |
| 3.5 cottahs | 2,520 sq ft (234.2 m²) | ≈58.9% | ≈1,483 sq ft | ≈1,037 sq ft |
| 4 cottahs | 2,880 sq ft (267.6 m²) | ≈57.8% | ≈1,664 sq ft | ≈1,216 sq ft |
Rule 70 / Table 4: 60% coverage up to 200 m², interpolated down to 50% at 500 m² and above. Verified directly from the KMC Building Rules, 2009 (Kolkata Gazette Extraordinary, 9 September 2009). [S1]
| Building height | Front | Side 1 | Side 2 | Rear |
|---|---|---|---|---|
| Up to 7.0 m | 1.2 m | 1.2 m | 1.2 m | 2.0 m |
| Above 7.0–10.0 m | 1.2 m | 1.2 m | 1.2 m | 3.0 m |
| Above 10.0–12.5 m | 1.2 m | 1.2 m | 1.5 m | 3.0 m |
| Above 12.5–15.5 m | 2.0 m | 1.5 m | 2.5 m | 4.0 m |
| Above 15.5–20.0 m | 3.5 m | 4.0 m | 4.0 m | 5.0 m |
| Above 20.0–25.5 m | 5.0 m | 5.0 m | 5.0 m | 6.5 m |
| Above 25.5–40.0 m | 6.0 m | 6.5 m | 6.5 m | 8.5 m |
Rule 62, KMC Building Rules 2009 — verified in full; the “above 7–10 m” row applies to the 3.5–4 cottah reference case used throughout this page (1.2 m / 1.2 m / 1.2 m / 3.0 m). [S1]
| Road width | Residential FAR | Max height (standard) | Max height (with 2.5–5 m land gift) |
|---|---|---|---|
| Up to 2.4 m (≈7.9 ft) | Nil | 7.0 m | — |
| Above 2.4–3.5 m (≈8–11 ft) | 1.25 | 7.0 m | — |
| Above 3.5–7.0 m (≈11–23 ft) | 1.75 | 10.0 m | 12.5 m |
| Above 7.0–9.0 m (≈23–30 ft) | 2.00 | 20.0 m | 25.5 m |
| Above 9.0–15.0 m (≈30–49 ft) | 2.25 | 40.0 m | — |
| Above 15.0–20.0 m (≈49–66 ft) | 2.50 | No restriction | — |
| Above 20.0–24.0 m (≈66–79 ft) | 2.75 | No restriction | — |
| Above 24.0 m (≈78.7 ft) | 3.00 | No restriction | — |
Table 3 (Rule 69) and Table 5 (Rule 74), KMC Building Rules 2009. The 12 ft (≈3.66 m) reference case used throughout this page — FAR 1.75, max height 10 m — matches this table exactly. [S1]
Setback & coverage visualizer
This is the tool to actually size your plot: enter its real dimensions and road width to see the buildable footprint, required open space and an animated massing model update live — combining all three rules above in one place. All figures are planning estimates from the tables above — not a sanctioned plan.
📐 Plot & building inputs
📊 Result
Setbacks applied at 9.0 m height (Rule 62, verified): Front 1.20 m (3.94 ft) · Left 1.20 m (3.94 ft) · Right 1.20 m (3.94 ft) · Rear 3.00 m (9.84 ft). Ground coverage is the binding limit here.
🗺️ Top-down site plan (to scale)
The dashed outline is the maximum envelope Rule 62 setbacks allow; the solid block inside is the smaller, coverage-capped footprint that actually governs here — its exact shape within the envelope is an architectural choice, not a specific rule.
🏗️ Animated massing model
A proportional 3D box of the buildable footprint and height, sitting within the full plot. Built in pure CSS 3D (no canvas) so it keeps animating even if a host page blocks JavaScript.
Shown: 36 × 70 ft plot (3.50 cottahs) on a 12 ft road → targeting G+2 (9.0 m) → binding footprint ≈1,483 sq ft, leaving ≈1,037 sq ft (41%) open. This model updates live as you change the inputs above.
⚠️ Disclaimer: this tool estimates planning feasibility from the KMC Building Rules, 2009 (independently verified for the figures marked ✓) and from a circulating claim of a 2025 amendment for the figures marked ⚠️ (not independently confirmed — see sources below). It ignores plot-specific factors a surveyor would catch — irregular boundaries, easements, heritage status, water bodies, existing encroachments, and road-widening reservations. Engage a KMC-licensed architect before finalising any plan.
Worked example & common misconceptions
Old house (assumed, pre-demolition): ~2,520 sq ft footprint × 3 floors ≈ 7,560 sq ft gross, covering virtually the whole plot.
FAR ceiling for the new build: 2,520 sq ft × FAR 1.75 = 4,410 sq ft total across all floors.
That’s about 3,150 sq ft less gross area than the old house — before setbacks or parking are even considered.
Ground-floor footprint (base rule, ≈58.9% coverage): ≈1,483 sq ft.
Footprint after setbacks alone (G+2 ≈ 9 m high, standard Rule 62 setbacks on a 36×70 ft plot): ≈1,581 sq ft.
Here, ground coverage is the binding limit, not the setbacks — the visualizer above shows this crossover for your own plot shape.
An old Kolkata building may well have been built wall-to-wall with its neighbours under long-superseded rules or informal permissions. An existing common wall does not automatically entitle you to rebuild on that boundary after a complete teardown. Certain alteration/redevelopment scenarios have separate provisions, but a full demolition-and-rebuild should not assume the old common-wall arrangement carries over. [S2]
