The flat looked perfect, and the price was right, so Vikram almost skipped the boring part. His lawyer insisted on comparing the sanctioned building plan against the building that actually stood on the plot. The plan showed four floors. The building had five. That extra floor, and every flat on it, was unauthorised construction the builder had quietly added beyond the approval. Vikram was about to buy a flat on that fifth floor. One document, laid next to the real building, saved him from buying a home the authorities could one day order demolished. The check took an afternoon of careful comparison. Skipping it could have cost him everything he was about to pay.

The short answer. The sanctioned building plan is the approval that makes a Bengaluru building legal, and before you buy you should confirm three things, that it exists, that it comes from the correct authority, and that what has been built matches it. The trade off is a little effort now against a large risk later. Verifying the plan is unglamorous work, but a building that departs from its sanction can lose you your occupancy certificate, your khata, your loan and your peace of mind.

What is a sanctioned building plan?

A sanctioned building plan is the design of a building that the local planning authority has formally approved before construction begins. It sets out the essentials the authority has signed off on, including the number of floors, the setbacks the building must leave from the plot boundaries, and the built up area permitted under the applicable rules. Construction is meant to follow this approved plan faithfully. When a building matches its sanctioned plan, it is authorised. When it departs from it, the departure is, to that extent, unauthorised, no matter how solid or attractive the finished structure looks. This is the heart of why the plan matters to a buyer. A beautiful building is not necessarily a legal one, and only the sanctioned plan, checked against the real structure, tells you which you are looking at.

The plan is not an internal builder document you have to take on trust. It is an approval granted by a public authority, which means it can be verified, and a buyer is entitled to see it before committing.

Does RERA registration mean the plan is fine?

Not on its own, though RERA does help you find the plan. For a registered project, the builder has to declare project details, including approvals, on the state RERA portal, so the Karnataka RERA listing is a good starting point to confirm that an approved plan exists and to read the declared particulars. But RERA registration is not the same as certifying that the building on the ground matches the sanctioned plan. A project can be RERA registered and still be built with deviations from its approval, because RERA registration and physical compliance with the plan are two different things. So use the RERA record to locate and cross check the approvals, and then do the separate, physical work of comparing the sanctioned plan against the actual structure. Treating a RERA number as proof that everything is built correctly is a common shortcut, and it is exactly the shortcut that leaves buyers exposed. The registration tells you the project is on the regulator radar and its papers are declared. Only your own comparison of plan to building tells you whether those papers match the bricks.

Why does verifying it protect you?

Because unauthorised construction quietly poisons everything that comes after the purchase. If a builder has built beyond the sanction, whether an extra floor, extra units, or reduced setbacks, that excess is not authorised, and the consequences land on whoever owns the flats. Unauthorised construction can hold up or deny the occupancy certificate for the building, which in turn blocks your individual khata, which blocks putting property tax in your name and clean resale. Banks are wary of lending against unauthorised portions, and a future buyer doing their own diligence will find exactly what you should have found. In the worst cases, authorities can order the unauthorised portion removed. None of this is visible when you walk through a well finished flat. It is visible only when you lay the sanctioned plan next to the building, which is precisely why the check exists. Our guide on the bank legal and technical verification covers how lenders look at the same question.

The reassuring part is that the check is entirely doable. The sanctioned plan is a real document, the building is right in front of you, and comparing them needs care rather than genius. If reading a plan feels daunting, this is exactly the kind of task an advocate or a technical consultant does routinely, and their fee is trivial next to the value of the flat. But even a careful buyer with no technical background can catch the obvious things, an extra floor, a wing that is not on the plan, a garden that has become a building, simply by standing on the site with the plan in hand.

What exactly should you compare?

Compare the approved plan against the building on the ground, feature by feature. Start with the number of floors, the most common place deviations hide, as Vikram discovered. Then look at the footprint and the setbacks, whether the building leaves the required open space around it or has crept into the margins. Check whether the number of units matches, and whether spaces shown as common areas or parking in the plan have been converted into extra saleable flats. Confirm the plan was approved by the correct authority for that location, because different areas of the city fall under different bodies, and an approval from the wrong authority is a problem in itself. The table below sets out the core checks.

Read the last row carefully. A minor, permitted variation is normal in real construction and not a cause for alarm. What you are hunting for is a large, unexplained gap between the paper and the building, the kind that signals genuine unauthorised construction rather than ordinary tolerance. The clearest tell is anything that adds saleable area the authority never approved, because that is where a builder profit motive and your legal risk collide most directly.

How does this connect to deviations and their fixes?

It connects directly, because verifying the plan is how you find a deviation in the first place. Some deviations can be regularised through official schemes, sometimes within a permitted tolerance, but regularisation is neither automatic nor guaranteed, and it can carry costs and conditions. As a buyer, you do not want to inherit an unresolved deviation on a hope that it will be regularised later. The safer stance is to find the deviation before you pay, and to insist that the builder resolve it, produce the occupancy certificate, and deliver a building that matches its sanction, rather than buying the problem and the uncertainty along with the flat. Our explainer on building deviations and regularisation covers how these are dealt with and why they are better avoided than inherited.

How should a Bengaluru buyer run this check?

Ask for the plan, compare it to the building, and refuse to pay until any gap is explained. This is not work you can outsource to a brochure or a smile. Walk through the checklist below in order.

1. Ask the builder for the sanctioned building plan and confirm it is the approved version.
2. Check that the plan was approved by the correct authority for the property location.
3. Count the floors on the plan and compare them to the floors actually built.
4. Compare the footprint, setbacks and number of units against the real structure.
5. Check whether common areas or parking have been converted into extra flats.
6. Confirm the project occupancy certificate, which the authority grants only for compliant buildings.
7. If you find a material deviation, pause and resolve it in writing before paying anything.

Following this order turns a frightening risk into a routine inspection. For a project such as Brigade Calista at Budigere Cross, asking to see the sanctioned plan and confirming the building matches it is the kind of quiet, unglamorous check that separates buyers who sleep well from those who spend years fighting a problem they could have seen on day one. The building you can see is only half the picture. The sanctioned plan is the other half, and you should never buy without holding both up to the light together. It is the one check that no amount of finish, furniture or friendly sales talk can substitute for.

Common questions from Bengaluru buyers

What is a sanctioned building plan?

A sanctioned building plan is the design of a building formally approved by the local planning authority before construction begins. It fixes details like the number of floors, the setbacks from the boundary and the permitted built up area. Construction is meant to follow this approved plan, and a building that does not match it is to that extent unauthorised.

Why should I verify the sanctioned plan before buying?

Because it tells you whether the building is authorised and whether what has been built matches what was approved. If a builder added extra floors or units beyond the sanction, that excess is unauthorised and can block your occupancy certificate and khata, invite penalties, and cause loan and resale problems later.

Who approves building plans in Bengaluru?

Building plans in Bengaluru are approved by the relevant local planning authority for that location, historically bodies such as the city corporation or the development authority, now under the reorganised city administration. Which body applies depends on where the property sits, so part of your check is confirming the plan was approved by the correct authority for that area.

What if the building deviates from the sanctioned plan?

Deviations beyond the permitted tolerance are unauthorised construction. They can hold up the occupancy certificate, trigger penalty or regularisation demands, and make banks and future buyers wary. A small, permitted variation is normal, but a large unexplained gap between the sanctioned plan and what stands on the ground is a serious warning you should resolve before paying.

Last updated 2026-08-08. PropNewz Team.