How to Verify an Approved Building Plan / Sanction

Somewhere in your folder of project documents is a sheet labelled "approved plan" or "sanctioned layout." It has a stamp in one corner, a string of numbers you don't recognise, and a drawing that may or may not match the show-flat you just walked through. The salesperson said the plan is "approved." You have no independent way to know if that's the plan that's actually being built, or a marketing version dressed up to look official. This guide walks through exactly how to read a sanctioned building plan yourself — the stamp, the number, the authority, the FSI figures — so "approved" stops being something you take on faith.

Who Sanctions a Building Plan, and What "Approved" Actually Means

Before any building can legally come up, its plan must be sanctioned by the competent local authority — which one, specifically, depends on the city. In Bengaluru, that is typically the Bruhat Bengaluru Mahanagara Palike (BBMP) or the Bangalore Development Authority (BDA), depending on the land's jurisdiction. In Mumbai, it is the Municipal Corporation of Greater Mumbai (MCGM). In many other cities it is a Development and Town-and-Country Planning (DTCP) authority, a local urban development authority, or the municipal corporation itself. "Approved" or "sanctioned" means this specific authority has reviewed the plan against applicable building bylaws — permissible Floor Space Index (FSI) or Floor Area Ratio (FAR), setbacks, height restrictions, parking norms, and fire and structural safety requirements — and issued a formal sanction, usually a stamped drawing set plus a sanction letter or order carrying a reference number and a validity period.

The key distinction to hold onto: a sanctioned plan is a specific, dated, numbered document tied to one authority. A "typical floor plan" render in a brochure, or a show-flat's layout, is not automatically the same thing — it may match the sanctioned plan exactly, or it may show a marketing variation. Your job is to find the actual sanctioned document and compare.

Step by Step: Locating and Reading the Sanctioned Plan

1. Ask for the sanctioned-plan PDF specifically — by name — rather than accepting a general "floor plan" brochure. In most states this is also attached to the project's RERA listing as a mandatory disclosure.
2. Find the sanction stamp on the drawing. It should show the sanctioning authority's name, an official seal or digital signature, and a sanction/approval number.
3. Note the sanction number and date, and separately note the validity period — sanctions are typically valid for a fixed number of years, after which they may require revalidation if construction hasn't reached a certain stage.
4. Read the approved FSI/FAR and setback figures printed on or attached to the drawing — these define how much built-up area and what building footprint the authority actually permitted on that plot.
5. Cross-check the sanctioned plan against the project's RERA listing, where the same document is typically filed as an attachment — a mismatch between what's filed on RERA and what you're shown separately is worth raising directly.
6. Compare the sanctioned layout to the marketing layout or show-flat unit by unit, where practical — noting any differences in wall placement, balcony area, or common spaces as facts to ask about.
7. If anything looks inconsistent, take both documents to an independent professional — an architect or structural engineer not engaged by the promoter — for a proper review; this is a job for a licensed professional, not a DIY judgement call.

Sanctioned-Plan Fields Decoded

Which Authority Sanctions Plans, City by City

Because India's urban planning and building-approval framework is administered at the state and municipal level rather than centrally, the sanctioning authority genuinely differs by city and sometimes by zone within a city. Bengaluru splits jurisdiction between BBMP (within municipal limits) and BDA (for certain planned layouts); Mumbai routes through MCGM; many state capitals and Tier-2 cities route through a DTCP or a dedicated development authority for that urban agglomeration. If you are buying in an unfamiliar city — a common situation for NRI buyers or anyone relocating for work — the first useful question to ask a local professional or the promoter directly is simply: "which authority sanctioned this plan, and can I see the number?" That single question, answered with a specific authority name and number you can independently look up, tells you far more than any brochure claim.

Sanctioned Plans and RERA — How They Connect

In most states, a project's RERA registration application requires the promoter to attach the sanctioned building plan as a supporting document, which is why you'll often find the same drawing set (or a reference to it) inside the project's RERA listing alongside its registration number, carpet-area declarations, and completion-date commitments. This is a useful cross-check: if the sanctioned plan you're shown separately by the sales team doesn't match what's filed against the same project's RERA number, that discrepancy is worth raising immediately and in writing.

A Real-World Mini Scenario: Marketing Layout vs. Sanctioned Plan

Imagine a brochure layout shows a 3BHK unit with an open balcony running the full width of the living room. When you pull the sanctioned plan filed with the local authority, the same unit's balcony is shown at roughly two-thirds that width, with the remainder marked as a service area. This is exactly the kind of fact-level discrepancy the sanctioned plan exists to catch — it does not, on its own, tell you whether the difference is a later approved amendment, a drafting variation, or an actual deviation under construction. What it does tell you is precisely what to ask next: "has an amended plan been sanctioned for this change, and can I see that document too?" Bring both drawings to an independent professional if the promoter's answer doesn't fully resolve it.

Spotting Deviation as a Fact to Confirm, Not a Verdict to Render

"Deviation" simply means a difference between what was sanctioned and what is actually being built or has been built. It is common enough in Indian construction that regulators and municipal processes have formal mechanisms for regularising certain deviations after the fact, and not every deviation is material to a buyer's decision. What matters for you as a buyer is not memorising every regulation around deviation, but recognising it as a specific, checkable fact: does the constructed or under-construction structure match the sanctioned drawing's footprint, height, and setbacks, or not? If you notice or suspect a mismatch, the responsible next step is a site inspection and document review by a licensed architect or structural engineer — DrawMagic's professional directory can help you find one — rather than drawing your own conclusion about the promoter or the project from a comparison you're not qualified to make alone.

Pro Tips for Verifying a Sanctioned Plan

• Ask for the sanctioned plan by its specific document name, not "the floor plan" — sales teams sometimes conflate the two.
• Photograph or scan the sanction stamp and number clearly for your own records before you rely on a verbal assurance.
• Check the sanction's validity window against the project's stated completion timeline — a plan nearing the end of its validity period on a project with years left to build is worth a direct question.
• Cross-reference the sanctioned unit's carpet area with DrawMagic's carpet area calculator to make sure the area you're being sold matches the sanctioned figure.
• When in doubt, pay for one hour of an independent architect's time to review the sanctioned plan against the marketing layout — it is a small cost relative to the purchase.

Common Mistakes to Avoid

• Accepting a "typical floor plan" render as proof of sanction without seeing the actual stamped document.
• Assuming the sanctioning authority named by the sales team is correct without confirming it has jurisdiction over that specific plot.
• Not checking the sanction's validity period, especially on projects with long construction timelines.
• Treating any noticed deviation as automatic proof of wrongdoing rather than a fact to raise and get professionally reviewed.
• Failing to cross-check the sanctioned plan against the same project's RERA listing, where it is often filed as a public attachment.

Where DrawMagic Fits — Organising, Never Certifying

Sanctioned plans, RERA listings, and municipal records are public and free to access — DrawMagic does not sell access to them, and it never certifies, verifies, or guarantees any builder, project, or plan. DrawMagic is an information and software platform, not a broker, financial or legal adviser, or certifying authority. What the evolving buyer intelligence workspace is built for is keeping the facts you've already gathered — sanction number, authority, FSI, validity date, RERA cross-reference — organised in one place alongside your affordability and locality research, so you're not re-hunting for a PDF three months into your search. Every fact carries its source and as-of date, consistent with the facts-plus-source-plus-date discipline described in DrawMagic's responsible-AI commitments. Personal data you choose to save is handled on a consent-first basis in line with India's Digital Personal Data Protection Rules, 2025, as outlined by Deloitte India.

For the broader picture of how DrawMagic supports each stage of a home purchase, start with the buyer overview, and sign up to begin organising your own due-diligence trail as you go.

Key Takeaways

• A sanctioned building plan is a specific, stamped, numbered document issued by a named local authority — not the same as a brochure's "floor plan."
• The sanctioning authority differs by city (BBMP/BDA in Bengaluru, MCGM in Mumbai, DTCPs and development authorities elsewhere) — always confirm which one applies to your plot.
• Check the sanction number, sanctioning authority, sanction date, validity period, approved FSI/FAR, and setbacks as separate, verifiable fields.
• Cross-check the sanctioned plan against the same project's RERA listing, where it is typically filed as a public attachment.
• Treat any difference between the marketing layout and the sanctioned plan as a fact to ask about, not a conclusion to draw alone.
• Deviation is a checkable, factual comparison between sanctioned and built/under-construction form — get it reviewed by an independent licensed professional, never self-diagnosed.
• Reconcile sanctioned carpet-area figures with DrawMagic's carpet area calculator before relying on a salesperson's number.
• DrawMagic's buyer intelligence workspace helps organise these facts over time — it never certifies or scores any builder, project, or plan.

FAQ

Is a project automatically compliant if it has RERA registration? No — RERA registration confirms mandatory disclosures were filed, including (in most states) an attached sanctioned plan. It does not independently re-verify every construction detail on an ongoing basis; the sanctioned plan itself is the document to check for plan-specific facts.

What should I do if I can't get a clear copy of the sanctioned plan? Ask in writing, reference the project's RERA registration number, and note that the sanctioned plan is typically a public-record attachment. If it's still not forthcoming, an independent professional or a formal query to the sanctioning authority is the next step.

Does a small deviation always mean something is wrong? Not necessarily — some deviations are common and have formal regularisation routes. The point of checking is to know the specific fact, not to assume either the best or worst case. A licensed professional can tell you whether a given deviation is material.

Can the sanctioned plan change after a project starts construction? Yes, amended or revised sanctions can be filed for genuine design changes. If you notice a difference between an earlier and later version, ask specifically whether an amended sanction exists and ask to see it.