FSI in Gujarat isn't one number — it's three stacked layers with different costs and caps. Here's how base, chargeable and TDR FSI actually work under CGDCR 2017, and where architects most often get the stacking wrong.
14 July 2026 · 8 min read
Floor Space Index (FSI) — the ratio of permissible built-up area to plot area — is the single most consequential number in any CGDCR 2017 compliance check. Get it wrong and every downstream calculation (BUA, height, parking, NOC triggers) is wrong with it.
Most first-time users of CGDCR treat FSI as one fixed figure per zone. It isn't. CGDCR 2017 stacks FSI in three distinct layers — Base, Chargeable, and TDR — each with its own eligibility rule, its own cost, and its own ceiling. Understanding how they stack, and where the stacking stops, is the difference between a design that clears scrutiny and one that gets sent back.
Base FSI is what you get automatically, no application or premium required, purely as a function of zone classification and road width (Table 6.2). A plot on a narrow internal road in a residential zone gets a lower base FSI than an equivalent plot fronting a wide arterial road in the same zone — road width is doing as much work as zone in this table as people usually assume zone alone does.
This is the number that shows up first in any compliance report: the FSI you're entitled to before you pay anything or apply for anything. It sets the floor for BUA, and every other FSI layer is additive on top of it.
Chargeable FSI (Clause 6.3.3(b)) lets you build beyond the base FSI by paying a premium — a rate in ₹ per sqm, set by the authority, multiplied by the chargeable FSI you're drawing and the plot area. This isn't unlimited: each zone has its own chargeable FSI cap layered on top of base.
The mistake we see most often: architects calculate the chargeable FSI cost correctly, but don't check it against the zone's absolute FSI ceiling before committing budget to it — which is where TDR comes in.
TDR is the third and final layer. Instead of paying a cash premium, a landowner who has surrendered land elsewhere (for road widening, a reservation, or a public purpose) receives a TDR certificate representing development rights, which can be purchased and loaded onto a different plot as additional FSI — again, up to a hard ceiling.
TDR FSI is acquired at a cost per sqm set by the market/authority schedule, not a fixed government rate like chargeable FSI, which is why TDR pricing needs its own line item in any project's financial model rather than being bundled with chargeable FSI cost.
Here's the part that trips people up: Base + Chargeable + TDR FSI together cannot exceed the zone's absolute maximum FSI, regardless of how much chargeable FSI cost or TDR you're willing to pay for. Every zone in CGDCR 2017 has this hard ceiling.
A design that mathematically sums to a valid BUA on paper can still fail compliance the moment total utilised FSI (base + chargeable + TDR) crosses that zone cap. This single check — total utilised FSI vs. zone absolute max — is worth verifying before finalising massing, not after.
FSI isn't isolated — moving it changes other requirements:
Common Plot (COP): Plots crossing 2,000 sqm (or buildings exceeding 25m height on smaller plots) trigger a mandatory common open plot requirement (Sec 6.17.5 / Table 6.49) — typically 8-20% of plot area depending on use. Basement parking is FSI-free (Sec 6.3.2) — often the cheapest way to add parking capacity without touching your FSI budget at all. Height-triggered NOCs: crossing 15m pulls in a Fire NOC requirement (Sec 14); crossing 24m adds a mandatory fire lift; crossing 45m reclassifies the project as a tall building with full fire suppression requirements (Sec 14.5) and, separately, Chapter 12 eligibility (plots ≥ 500 sqm with road ≥ 15m) brings its own additional NOC stack (STC, wind tunnel study, EIA).
None of these are FSI rules exactly, but all of them move in response to the FSI and height decisions you make — which is why a compliance check needs to run the whole waterfall together, not FSI in isolation.
This is exactly the calculation GeoRule automates: base FSI from Table 6.2 for your plot's zone and road width, chargeable FSI cost against the zone cap, TDR FSI against the same cap with its own acquisition cost line, and an automatic flag the moment total utilised FSI would exceed the zone's absolute maximum — before you've committed to a massing option.
The FSI slider in GeoRule's compliance report lets you move chargeable and TDR FSI independently and watch BUA, cost, and the absolute-cap flag update live, so the stacking math that usually lives across three CGDCR tables and a calculator sits in one view.
This article is for general informational purposes and reflects our understanding of CGDCR 2017 and current AMC/AUDA processes at the time of writing. It is not a substitute for professional architectural advice or verification with local authorities.