The short answer: FSI is calculated on what is left, not on what you bought. Regulation 3.9 defines the net plot area, and everything downstream in the code multiplies that number rather than the sale deed's.
Key takeaways
- Net area is the total plot minus amenity space under Regulation 3.5 and minus DP or RP proposals including new roads and road widening.
- Only the net area is used to compute FSI or built up area, in every land use zone.
- In a plotted layout the basic FSI of the net area may be spread pro rata or concentrated on chosen plots, subject to the receiving limit, and it must be shown on the layout plan.
- A plot from an already approved layout is treated as net plot area in full.
- Amalgamation needs contiguity and a sizable plot from a planning point of view.
- Plots split by a minor nallah or a road may be amalgamated if the owner builds a connecting bridge or underpass.
- A lawful non-conforming use existing before the plan continues, and may expand within the original sanctioned permission.
- But rebuild it and the new building must conform.
- Public and semi-public zone permits up to 15 percent commercial, with an explicit exclusion list.
Net plot area
Chapter 3, Regulation 3.9, Net Plot Area and Computation of FSI is four clauses and it governs every FSI calculation in the code.
Net area is the balance plot area after deducting:
- the area covered by amenity space under Regulation 3.5, and
- Development or Regional Plan proposals including new roads and road widening, if any.
For computing FSI or built up area, the net area only shall be considered. And clause (v) confirms the rule applies in all land use zones, so there is no zone in which the gross area is used.
| Situation | What counts as net |
|---|---|
| A fresh plotted layout, subdivision, group housing scheme or any development | Total plot minus amenity space and DP or RP proposals including new roads and road widening |
| A plot from an already approved layout | The plot area is treated as net plot area in full |
| Distribution across a plotted layout | The basic FSI of the net area may go pro rata to all plots, or to certain plots as the owner desires, subject to the maximum receiving potential, and stated clearly on the layout plan |
Clause (iv) is the one that resolves a recurring argument, and it works in the buyer's favour.
A plot from an already approved layout is net plot area in full. The deductions were made once, when the layout was approved. A purchaser of an individual plot out of that layout does not deduct again for the roads and amenity space that were carved out of the parent land, because the plot they hold is already what remained.
The rule for a fresh development is the opposite, and that is where the confusion starts: a developer buying raw land computes FSI on what is left after the amenity space and any DP road or reservation come out, which is frequently 15 to 25 percent less than the area on the sale deed.
Clause (iii) is a genuine flexibility rather than a constraint. In a plotted layout the FSI does not have to be spread evenly. It can be concentrated on chosen plots, up to their receiving limit, provided the layout plan says so. Which means that in an approved layout, two plots of identical size can carry different entitlements, and only the layout plan will tell you.
Amalgamation
Chapter 3, Regulation 3.12, Amalgamation of Plots permits it on two tests and one exception.
Amalgamation is permissible where the plots form a sizable plot from a planning point of view and are contiguous. An amenity plot and a layout plot may also be amalgamated, provided the amenity is developed on a proportionate area.
Amalgamation of plots from an approved layout that is not desirable from a planning point of view is not permitted, and the regulation illustrates the case rather than defining it, which leaves it with the Authority.
The exception is the useful one: land separated by a minor water course or nallah or road may be entitled to amalgamation, provided the owner constructs a connecting over bridge or underpass of sufficient width and strength, with the Authority's approval. That is the same principle the Integrated Township Project uses at a much larger scale, where land divided by nallahs, roads or railways counts as contiguous if the proponent builds the connections at his own cost.
Chapter 3, Regulation 3.13, Development of Cycle Track Along River and Nallah sits next to it and is worth knowing because it takes a strip rather than a plot. Along a minor water course, 6.0 m is left as marginal distance, and 3.0 m of that strip is available as a public cycle track, with the compound wall built outside it. The owner keeps the FSI of that strip in situ, and on handing the 3.0 m over to the Municipal Corporation is entitled to TDR or in situ FSI equal to 35 percent of its area. The provision applies only where the Commissioner has identified the green belt and nallahs, and the Commissioner is directed not to identify stretches where development has already made a cycle track impossible.
The zone rules that are easy to miss
Chapter 4, Regulation 4.1, General opens Chapter 4 with four general provisions, and three of them decide real cases.
Banded by clause
- (i) ConformityThe intended use must conform to the land use, or the purpose of designation, allocation or reservation assigned in the Development Plan, Regional Plan or planning proposal, unless specified otherwise
- (ii) Lawful non-conforming useA lawful non-conforming use existing before the plan came into force continues, and may be expanded within the holding in the original sanctioned permission. But when the building is pulled down or falls down, the new building must conform
- (iii) Existing featuresFeatures shown on the plan are INDICATIVE and stand modified per the actual situation. Survey boundaries, road and nallah alignments follow the Land Records measurement plan, and land unaffected by those features may be developed under the adjoining predominant zone
- (iv) ParkingThe Authority may develop land it owns or possesses for public parking, single or multi-storeyed, underground or above ground, irrespective of its existing or proposed use in the plan
Source: Chapter 4, Regulation 4.1, UDCPR as updated 30 January 2025
Clause (iii) is a provision worth more than its length, and it is the answer to a question that comes up on almost every parcel with a nallah drawn across it.
Existing features shown on the Development or Regional Plan are indicative and stand modified per the actual situation. A nallah alignment, a road line or a survey boundary drawn on the plan does not override where those things actually are. The measurement plan of the Land Records Department governs, and land unaffected by such physical features may be developed for the uses permissible under the adjoining predominant zone.
So a strip that a plan appears to sterilise because a nallah is drawn through it is not necessarily sterilised. The right document is the Land Records measurement plan, not the Development Plan sheet.
Clause (ii) runs in the same direction for a different reason. A use that was lawful before the plan changed survives the change, and may even expand inside the original sanctioned permission. What it cannot survive is being demolished. That is a live consideration in any redevelopment of an old commercial building in what is now a residential zone: the moment it comes down, the entitlement to the old use goes with it.
Chapter 4, Regulation 4.10, Public / Semi Public Zone permits schools, colleges, training institutions and student hostels; homes for the aged, hospitals, sanatoria, dispensaries, maternity homes and health centres with ancillary structures; Government and local self-government offices, courts and public housing; public and semi-public utility and transport establishments and institutions of research, education and health; and libraries, mangal karyalayas, gymnasia, gymkhanas, stadia, community halls, civic and cultural centres, religious structures and auditoria.
It also permits commercial use up to 15 percent, with an explicit exclusion list: no shop or permit room for liquor, wine or beer, pan, cigarettes, tobacco or lottery tickets, nor other uses that do not serve a public purpose, nor storage of domestic gas cylinders or kerosene.
Chapter 4, Regulation 4.15, Tourism Development Zone is the shortest zone in the chapter and it borrows entirely. Permissible uses are all uses permissible in the Agricultural Zone, except two specific entries of Regulation 4.11, plus gaothan expansion under Regulation 5.1.1. Anyone expecting a tourism zone to carry its own resort and hotel entitlements should read that carefully: the answer is in the agricultural zone's list, not here.
Four short provisions worth naming
Chapter 9, Regulation 9.18, Letter Box requires a letter box of appropriate dimensions on the ground floor of residential and commercial buildings. Chapter 9, Regulation 9.19, Meter Room requires a meter room as per the requirement of MSEDCL or the power supply company, per the number of tenements or units.
Both are one line each and neither has a dimension in it, which is worth knowing precisely because a buyer asking why the meter room is where it is will find the answer sits with the utility rather than in this code.
Chapter 11, Regulation 11.2.5, Transferable Development Rights (TDR) against Construction of Amenity# is the third. Where an owner or lessee, with prior approval, develops or constructs an amenity on the surrendered plot at his own cost and hands it over free of cost to the Authority, Construction Amenity TDR is granted by the formula A divided by B, times 1.35, where A is the cost of construction per the Public Works Department's DSR for the year construction commenced. The Authority may compute A comprehensively, including civil, electrical, water supply, drainage and development works such as site levelling, compound wall, parking, driveways and basement ramps, environmental compliance infrastructure, and incidental costs.
That 1.35 multiplier is the incentive: build the amenity and hand it over, and the TDR granted exceeds the construction cost divided by the land value ratio by 35 percent. It is the mechanism the Integrated Township and Urban Renewal Scheme both refer out to when a proponent builds the amenity rather than just handing over the land.
Chapter 12, Regulation 12.7, Signs and Outdoor Display Structures closes the set. Advertising signs on buildings and land follow Part 10 Section 2 of the National Building Code, plus the Authority's own by-laws. And no advertising sign or outdoor display structure is permitted on buildings of architectural, aesthetical, historical or heritage importance, nor on Government buildings, except that a Government building may carry signs relating to its own purposes or programmes.
What the register shows
MahaRERA publishes the filed land area for every project. It does not say whether that figure is gross or net, and there is no separate field for amenity space or for area under a DP road.
That single ambiguity is why FSI cannot be audited from a filing. Dividing the filed permissible FSI by the filed land area produces a distribution whose 99th percentile sits above 20, which no zone in Maharashtra permits. Part of that is the gross-versus-net question and part is that RERA registers phases against parcels that need not match the sanctioned layout.
So the honest statement is the useful one: the filed land area is a real number the promoter has certified, and it is worth checking against the sale documents and the sanctioned plan, but it is not a basis for computing what may be built. That comes from the layout plan, which under Regulation 2.2.5(a) must carry the area statement and every DP proposal crossing the site, and which is a public document for the life of the project.
Related rule cards
- What is not saleable area
- Restricted zones and where the FSI goes
- Layout roads and minimum plot sizes
- How to read a sanctioned plan without being an architect
Where the filings come in
Net plot area, amalgamation and zone conformity are settled in the building permission.
The register carries the promoter's own certified figures, free at reragenie.com: the filed land area, the buildings and their floors, the sanctioned and sold units where filed, the promoter's extension history with reasons, the certifying professionals, and any complaints or litigation with case numbers.
ReraGenie's project analysis, Rs 2,999 for one project, reads the full filing and the documents behind it. The area consolidated report covers a whole micro-market at Rs 2,999 for the first project and Rs 1,999 per additional one.
Source: Unified Development Control and Promotion Regulations for Maharashtra, UDCPR as updated 30 January 2025. Sanctioned under the Maharashtra Regional and Town Planning Act, 1966.
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