Illegal and unauthorised construction in redevelopment — how to keep your society safe

Unauthorised construction in redevelopment means your developer has built something the municipal corporation never sanctioned — extra floors, more built-up area than the approved Floor Space Index (FSI, the ratio that fixes how much can be built on a plot), or structures that eat into open spaces and set-backs (the gaps that must be left around a building for light, air and fire access). It matters because the rulebook is strict: under the Development Control and Promotion Regulations 2034 (DCPR 2034), which govern construction in Greater Mumbai, every building must follow its sanctioned plan, and any work that goes beyond it can be refused an Occupancy Certificate (OC), penalised, or even demolished. This guide is written to be used, not just read. It gives you the exact documents to demand and what each one proves, six checks a committee can run on site in a weekend, the arithmetic to test the FSI figure printed on the plan, the officer at MCGM Building Proposals to write to and what the letter must contain, the provision to cite, the clock a Section 53 notice starts, and what all of it means for a member or an outside buyer.

What counts as unauthorised construction

Every redevelopment is built against a set of approvals — the IOD (Intimation of Disapproval, the corporation's first set of conditions), the Commencement Certificate (CC, permission to start building) and the sanctioned plans that fix the height, layout and permissible built-up area. Construction becomes unauthorised the moment it strays beyond those approvals without a fresh, amended sanction. In reported cases the common forms include:

• Adding extra floors or flats beyond the sanctioned number.
• Consuming more FSI than the plot legally supports, or claiming Transfer of Development Rights (TDR) or premium FSI that was never actually loaded and approved.
• Encroaching on marginal open spaces and set-backs — the mandatory gaps around the building.
• Building over recreation ground, podium or open space meant for members' common use.
• Converting stilt parking, refuge floors or common amenities into saleable flats.
• Quietly building differently from the approved plan and hoping to "regularise" it afterwards.

DCPR does not leave this to argument. Regulation 11(5) says that if any departure of a substantial nature from the sanctioned plans is intended during construction, prior sanction of the Commissioner is mandatory and a revised plan must go through the same procedure as the original — and that any work done in contravention of the sanctioned plans, without prior approval of the Commissioner, shall be deemed unauthorised. There is a second, quieter route to the same result: Regulation 10(7) says the development is to be considered unauthorised if it is carried out without the requisite fees, development charges, premium and development cess actually being paid. So a plan that shows premium FSI or TDR the developer never paid for does not make that extra area legal. Ask for the payment receipts, not just the drawing.

Source: DCPR 2034, Regulation 10(7) (payments) and Regulation 11(5) (deviation during construction).

Unauthorised work rarely appears as one dramatic act. Because most members are living in rented transit homes during construction and cannot watch the site every day, small deviations often go unnoticed until the structure is already up. By then, removing an illegal floor is far harder — and far more painful — than preventing it in the first place. Our guide on transit and construction explains how to keep a watchful eye even while you are away.

Why a deviation puts every member at risk

The developer may profit from the extra flats, but the risk sits squarely with your society. An unauthorised structure can invite a stop-work notice or a demolition order, and it almost always blocks the OC — the single most important document for your new building.

No Occupancy Certificate, no peace of mind

An OC certifies that the building is complete exactly as approved and is fit for legal occupation. Under DCPR 2034, unauthorised construction is a direct ground to deny the OC. Without it, occupying the building is technically illegal: banks hesitate to sanction home loans against the flats, buyers walk away, property tax and water charges can be levied at penal rates, and utility connections may only ever be temporary. Members can end up owning a flat they cannot easily sell, mortgage or insure — a heavy price for a deviation they never agreed to. Our page on the risks of no Occupancy Certificate sets this out in detail.

Warning signs, and how to protect your society

You do not need to be an engineer to catch most problems. Watch for these signs on and around the site, and act on each one early — in writing, and as a committee rather than as a lone worried member.

The rules that already protect you

Four provisions do most of the work for a society trying to keep its redevelopment honest. Quote them by number — a letter that cites a section is handled differently from one that only complains.

• DCPR 2034, Regulation 9(1) — nothing without permission. No person shall erect or re-erect a building, alter any building, or carry out any development or redevelopment on any plot without obtaining development permission and a Commencement Certificate from the Commissioner. Read DCPR 2034 explained for a plain-language overview.
• DCPR 2034, Regulation 12(4)(a) — the enforcement hook. In case of unauthorised development the Commissioner shall take suitable action, which may include demolition of the unauthorised works as provided in Section 53 of the Maharashtra Regional and Town Planning Act, 1966 and the relevant provisions of the Mumbai Municipal Corporation Act, 1888. This is the most useful line on this page: DCPR itself names the two statutes MCGM must act under, so your complaint can name them too.
• DCPR 2034, Regulation 12(4)(b) — the architect has a personal duty. It is the responsibility of the Architect or Licensed Surveyor on Record to inform the Commissioner immediately of any unauthorised work, and to tell the owner or developer in writing to stop the work — failing which suitable action will be taken against the architect or licensed surveyor. Their name is printed on your sanctioned plan. Send them a copy of every letter.
• DCPR 2034, Regulation 12(6) — a permission built on a lie can be cancelled. Without prejudice to the powers of revocation under Section 51 of the MRTP Act, the Municipal Commissioner may, after giving an opportunity of being heard, revoke a development permission where there has been any false statement or misrepresentation of a material fact in the application — and thereupon the work carried out under it is treated as unauthorised. Regulation 12(6)(ii) adds the sting: in that case no compensation shall be paid. Anyone who buys into such a building carries that risk personally.
• RERA Sections 14(1) and 14(2) — build as sanctioned, and no changes behind your back. Section 14(1) of the Real Estate (Regulation and Development) Act, 2016 requires the project to be developed and completed in accordance with the sanctioned plans, layout plans and specifications approved by the competent authority. Section 14(2) then bars the promoter from making other alterations or additions to those plans, layouts or specifications, or to the common areas, without the previous written consent of at least two-thirds of the allottees other than the promoter. That bar is not absolute: Section 14(2)(i) permits minor additions or alterations required by an allottee for that allottee's own apartment, and minor changes genuinely necessary for architectural or structural reasons, duly recommended and verified by an authorised architect or engineer, after proper declaration and intimation to the allottee. An extra floor, a shrunken recreation ground or a converted stilt is not that. Our note on changing sanctioned plans needs consent sets out the sequence in date order. Section 14(3) separately makes the promoter liable for structural or workmanship defects brought to notice within five years of possession, to be rectified within thirty days.

For a project outside RERA registration, the equivalent bar is Section 7 of the Maharashtra Ownership Flats Act, 1963, which stops a promoter altering the structure of the building without the previous consent of the flat purchasers. And a breach of Section 14 is not free: under Section 61 of RERA a promoter who contravenes any provision other than Sections 3 and 4 is liable to a penalty which may extend to five per cent of the estimated cost of the project as determined by the Authority.

Source: DCPR 2034, Regulations 9(1), 12(4)(a), 12(4)(b) and 12(6); Real Estate (Regulation and Development) Act 2016, ss. 14(1), 14(2), 14(2)(i), 14(3), 61; Maharashtra Ownership Flats Act 1963, s. 7.

How to check the built work against the sanctioned plan

Everything below can be done by a committee with no technical training. Do it in this order: get the paper, then read the paper, then walk the site with it in your hand.

Step 1 — the eight documents to obtain, and what each one proves

Ask the developer for all of these in one written letter, naming each. If any is refused, apply under Section 6 of the Right to Information Act, 2005 to the Public Information Officer at the Executive Engineer (Building Proposals) office of your ward at MCGM. The reply is due in 30 days under Section 7(1), and a first appeal lies under Section 19(1) within 30 days of a refusal or of the lapse.

Source: DCPR 2034, Regulations 10(4), 10(7), 11(4), 11(6), 11(7); Right to Information Act 2005, ss. 6, 7(1), 19(1).

Step 2 — six checks your committee can run this weekend

1. Read the site display board. Regulation 11(3)(ii) requires the holder of the development permission to keep posted in a conspicuous place on the site: a copy of the development permission or Commencement Certificate; a copy of the approved drawings and specifications; the list of Professionals on Record with their contact details; and copies of the remarks obtained from the various departments. If that board is absent or blank, that is itself a breach you can report the same day — and it tells you what the developer would rather you not read.
2. Check whether the CC is still alive. Under Regulation 10(6) a development permission or Commencement Certificate is valid for four years in the aggregate, but must be renewed before the expiry of one year from the date of issue, and may be renewed for only three consecutive one-year terms before a fresh proposal becomes necessary. Read the date on your CC. If it is over a year old with no renewal endorsement after it, ask for the renewal.
3. Count the floors against the CC endorsement, not against the brochure. Stand at the compound gate, count the slabs cast, and compare with the level named in the last endorsement. This single comparison catches the most common and most expensive version of this fraud.
4. Read the colours on the plan. DCPR fixes them, so you do not need an architect to interpret the sheet.
5. Measure the outside. Regulation 11(6) tolerates a deviation in outer dimension of only 25 mm, and only on condition that the carpet area remains unchanged. Anything visibly beyond that is not "site adjustment".
6. Ask for a surprise inspection. Regulation 12(1) allows the Commissioner to inspect at any time during erection of a building or execution of any work, without giving previous notice. Ask for exactly that in your letter — an announced inspection is worth far less.

Source: DCPR 2034, Table 2 (Colouring of Plans) and Regulations 10(6), 11(3)(ii), 11(6), 12(1).

Step 3 — test the FSI figure printed on the plan

The FSI calculation sheet is where an inflated claim shows up first, and you can sanity-check it with a calculator and two facts: the width of your access road, and how much of the plot is being surrendered. The figures below are illustrative — put your own in.

Three things to hold on to when you compare that against the sheet. First, the 2.20 already includes the premium and the TDR components — they are not stacked again on top, and each must actually be bought: premium is charged at 50% of the ASR land rate for FSI 1 under Regulation 30(A)(6), and TDR must be purchased and loaded under Regulation 32. Ask to see both sets of papers. Second, fungible compensatory area under Regulation 31(3) is granted over and above the admissible FSI by special permission of the Commissioner, so it will appear as its own line and is not by itself a deviation. Third, a 9.00 m road falls in the higher band: the sanctioned table reads "less than 9 m" for the basic band and "9 m and above but less than 12.00 m" for the next, so a nominal 9 m layout road carries 2.00 in the suburbs, not 1.00.

And the caveat that matters most: if your IOD names Regulation 33(7), 33(5), 33(9) or 33(10) — cessed, MHADA, cluster or slum schemes — Table 12 is not your ceiling at all. Each of those regulations sets its own FSI and its own incentive, and a much higher figure on the plan can be perfectly lawful. Read the regulation your IOD actually names before you allege anything. Our FSI calculator does this arithmetic for you.

Source: DCPR 2034, Table 12 (FSI by road width, Island City and Suburbs); Regulation 30(A)(2) (base of computation excludes DP roads and reservations to be surrendered); Regulation 30(A)(6) (premium at 50% of ASR land rate for FSI 1); Regulation 31(3) (fungible compensatory area); Regulation 32 (TDR).

Step 4 — cross-check the developer's own filings, and put one professional on your side

• Download the MahaRERA project page and date-stamp it. A registered project uploads its approved plans, FSI, floor details and the architect's, engineer's and chartered accountant's certificates against its registration number. That is the developer's own account of what he told the Authority, and it is the cheapest evidence a society will ever get.
• Appoint an independent eye. A society-appointed architect or Project Management Consultant, paid by the society and not by the developer, should certify the site against the sanctioned plan at every slab. Our tender & agreement review service helps you write that into the contract before work starts.
• Get the deviation certified in writing. Before you complain, have that independent professional produce a comparison sheet — sanctioned dimension against as-built, floor by floor and for every common area. A certified sheet turns a complaint into a case.

Concrete steps to protect your society

A demolition notice is far more expensive than prevention. A few disciplined steps keep your redevelopment on the right side of the law:

1. Read the agreement first. A sound development agreement fixes the sanctioned area, floor count and timelines, and makes any deviation a clear breach. See red flags in a development agreement.
2. Appoint a PMC before work starts and give them a written mandate to check construction against the sanctioned plan at every stage.
3. Insist on approved copies of the IOD, CC and plans, and keep a full society set safe with the committee.
4. Guard the open space. Protect your recreation ground, set-backs and podium; these belong to the members, not to the developer's sales book.
5. Withhold consent to changes unless the two-thirds vote required by RERA Section 14(2) has genuinely been taken, and never sign the consent before the amended plan is actually sanctioned.
6. Never accept possession without the OC, and hold back the final corpus instalment until it is produced.
7. Work from a checklist. Our redevelopment checklists give your committee a simple, step-by-step way to stay on top of every approval.

Where to complain at MCGM, and exactly what to send

Regulation 12(4)(a) already tells you what the corporation must act under. What follows is who to address it to, and what the letter has to contain so that it cannot be filed away as a vague grievance. In Mumbai this is MCGM (the BMC); outside Greater Mumbai the same letter goes to your own municipal corporation, and DCPR does not apply — UDCPR does.

The escalation ladder, in order

Do not skip rungs to save time. An escalation letter that attaches the earlier letter, its inward number and the date of the corporation's silence is far stronger than one that starts at the top with nothing behind it.

What the letter must contain

Put in every one of these, in this order. A letter missing the file reference or the CTS number is the easiest one for a busy ward office to lose.

1. The society's full registered name and registration number, and the address of the site.
2. The CTS or survey number of the plot, and the ward.
3. The IOD number and date and the CC number and date, copied exactly as printed, and the MahaRERA registration number if the project is registered.
4. The deviation stated in measurable terms — how many floors, which dimension, which set-back, which open space — not "illegal construction is going on".
5. The relief sought, provision by provision: inspection under Regulation 12(1); a stop-work direction; a notice under Section 53 of the MRTP Act, 1966; action under Section 351 of the MMC Act, 1888; and, where the permission itself rests on a misstatement, revocation under Regulation 12(6) read with Section 51 of the MRTP Act.
6. A list of enclosures: your independent architect's sanctioned-versus-as-built comparison sheet, dated photographs, and copies of the IOD, CC and sanctioned plan.
7. A line asking for an acknowledgement bearing the inward number and date. Collect it at the counter; do not leave without it.
8. Copies to: the developer, the Architect on Record, and MahaRERA.

Send it by registered post with acknowledgement due as well as by hand and by email. The postal receipt and the AD card are what fix the date of your objection if this ever reaches a tribunal.

Source: DCPR 2034, Regulations 12(1), 12(4)(a), 12(4)(b) and 12(6); Maharashtra Regional and Town Planning Act 1966, ss. 51 and 53; Mumbai Municipal Corporation Act 1888, s. 351.

What the committee must minute, and when

• At the first committee meeting after the deviation is seen: a resolution recording the date it was observed, authorising the Secretary to write to the Executive Engineer (Building Proposals), and appointing the independent architect. Note the resolution number — you will quote it in the letter.
• Within the same week: minute the despatch of the letter with its registered post number, and place the acknowledgement on the record.
• At every meeting after that: minute the corporation's reply, or the fact that none has come. A dated record of official silence is what supports an escalation.
• Never minute a ratification. Do not pass any resolution condoning, regularising or recording "no objection" to the extra construction, and do not sign consent to an amended plan before it is actually sanctioned. A consent given early is precisely what gets produced later as the two-thirds consent under RERA Section 14(2).
• Give members access. Under Section 32 of the Maharashtra Co-operative Societies Act, 1960 a member may inspect the society's records and obtain copies on payment of the prescribed fee. Circulate the correspondence rather than making members ask for it.

What a Section 53 notice is, and the clock it starts

Section 53 of the Maharashtra Regional and Town Planning Act, 1966 is the provision DCPR Regulation 12(4)(a) points to, and it decides whether the illegal portion comes down. Understand it before a notice arrives, because the notice is served on the owner of the land — and after conveyance that is the society and its members, not the developer who built the problem.

• What it does. Where development has been carried out without the permission required under the Act, or in contravention of a condition of the permission, the Planning Authority may serve a notice on the owner requiring him to restore the land to its condition before the development, or to secure compliance with the permission and its conditions. The notice can require the demolition or alteration of the building or works.
• The period. The notice must allow a period of not less than one month after service. Read your own notice for the period it actually specifies and diarise that date the day it arrives — every other step runs off it.
• The retention route. Section 53 also allows the person served to apply for permission to retain the work. While that application is pending the notice does not take effect, and if the permission is refused the notice revives. Put the bare text of Section 53 in front of your advocate before you rely on any of this timing: the sub-sections matter, and the periods are short.
• If the notice is not complied with. The Planning Authority may prosecute, and may itself carry out the demolition or restoration and recover what it spends from the owner — recovery being as arrears of land revenue, which is far harsher machinery than an ordinary money claim. That is why a Section 53 notice must never be allowed to sit in a file.
• The parallel municipal route. For a Mumbai building, MCGM also acts under Section 351 of the Mumbai Municipal Corporation Act, 1888, under which the Commissioner calls on the owner to show cause why work carried out contrary to the sanction should not be removed, altered or pulled down. A show-cause notice is an opportunity to be heard. Answer it, on record, within the time given.

Source: Maharashtra Regional and Town Planning Act 1966, ss. 51 and 53; Mumbai Municipal Corporation Act 1888, s. 351; DCPR 2034, Regulation 12(4)(a).

What this means for a buyer — and for a member

The developer who built the extra floor may be long gone. The consequence stays with whoever owns the flat. Five points decide how badly a buyer is exposed:

1. Registration is not proof of legality. An agreement for sale can be registered at the office of the Sub-Registrar of Assurances without any planning approval being verified there. A registered agreement proves you paid a price. It does not prove your floor was ever sanctioned.
2. The CC endorsement decides whether your floor exists in law. Ask for the Commencement Certificate and find the last endorsement. If it covers work up to the twelfth slab and your flat is on the fifteenth floor, three floors have no commencement certificate behind them and the whole of that portion is unauthorised under Regulation 11(5).
3. Without an OC, occupation is not lawful. Under Regulation 11(7) the Commissioner issues the Occupancy Certificate only after satisfying himself that there is no deviation from the sanctioned plans. No OC means home loans are refused or restricted, resale buyers walk away, property tax and water charges can be levied at penal rates, and the flat is hard to mortgage or insure. Our page on the risk of no Occupancy Certificate sets out the full consequence.
4. A revoked permission carries no compensation. Regulation 12(6) lets the Commissioner revoke a development permission obtained on a false statement or a misrepresentation of material fact, after a hearing — and Regulation 12(6)(ii) says no compensation is payable in that case. A buyer who paid full price for an unauthorised floor has no claim against the corporation for the loss.
5. The demolition bill lands on the owner. A Section 53 notice runs against the owner, and if the authority does the work itself the cost is recovered as arrears of land revenue. After conveyance, that is the society and its members.

Against this, RERA gives a buyer real leverage against the promoter. Under Section 11(4)(b) the promoter is responsible for obtaining the completion certificate or the occupancy certificate, or both, from the competent authority and for making it available to the allottees individually or to the association of allottees. Where he fails to complete or is unable to give possession in accordance with the agreement, Section 18 entitles the allottee to withdraw and claim a refund with interest, or to stay and claim interest for every month of delay.

The five-minute check before you buy a flat in a redeveloped building

1. Ask for the Occupancy Certificate (DCPR Annexure 20). If there is none, ask for the written refusal — Regulation 11(7) requires the reasons to be given in writing — and read what it says.
2. Ask for the Commencement Certificate with all endorsements and locate your floor on the last one.
3. Ask for the sanctioned typical floor plan and the FSI calculation sheet, and confirm your flat appears on them at the area you are being sold.
4. Ask the seller, in writing, whether any notice under Section 53 of the MRTP Act or Section 351 of the MMC Act has ever been served on the property, and get the answer on paper.
5. Apply under Section 6 of the RTI Act, 2005 to the ward Building Proposals office for the OC status and the last endorsed CC. It costs the prescribed fee and takes 30 days, and it is the only version of the answer that does not come from the seller.

Instruct your advocate that the title search must report specifically on the IOD, the CC and its endorsements, every amended plan and the OC — not only on the chain of title. A clean chain of title on an unauthorised floor is still an unauthorised floor.

Source: DCPR 2034, Regulations 11(5), 11(7), 12(6); Real Estate (Regulation and Development) Act 2016, ss. 11(4)(b), 18; Maharashtra Regional and Town Planning Act 1966, s. 53; Mumbai Municipal Corporation Act 1888, s. 351; Right to Information Act 2005, s. 6.

Your legal remedies, and the forum for each

Complaining to MCGM is the first step and it is the only one that can stop a slab. It does not get a member compensated. Run these in parallel, and file each in the right place the first time — a complaint in the wrong forum costs months.

See our note on why builder cheating can be criminal, and, if you are unsure which door to knock on, which forum hears a redevelopment dispute.

Source: Real Estate (Regulation and Development) Act 2016, ss. 11(4)(b), 14, 18, 31, 37, 61; Consumer Protection Act 2019, ss. 34, 47, 58, 69(1), read with the Consumer Protection (Jurisdiction of the District Commission, the State Commission and the National Commission) Rules, 2021; Maharashtra Co-operative Societies Act 1960, ss. 77, 91, 92; Bharatiya Nyaya Sanhita 2023, ss. 316 and 318; Bharatiya Nagarik Suraksha Sanhita 2023, s. 173(1).

Illegal construction is not something a society has to accept quietly. Caught early — with the right documents, an independent professional and a united committee — most deviations can be stopped before they harden into a demolition risk. If you would like a plain-language second opinion, register your society and our team will help you read the plans and the paperwork.