Through 2024 and 2025, Bengaluru buyers watched the state government wrestle with an uncomfortable fact: a large share of the city's buildings do not match the plans they were sanctioned on. In April 2025, Karnataka moved a draft notification that raised the deviation which can be regularised from 5% to 15%, an admission that plan violations are common rather than rare. Before you sign anything, the sanctioned plan is the single document that tells you whether the flat or house you are buying is actually legal.

The short answer. A sanctioned plan is the approved drawing that fixes your building's floors, height, setbacks and floor area, and anything built beyond it is a deviation. Karnataka has long tolerated deviations of roughly 5%, and a 2025 draft notification proposed raising the regularisable limit to 15% in Bengaluru, but extra floors and slashed setbacks usually sit far outside any tolerance band. The trade-off is blunt: a deviated building is often cheaper per square foot, yet it can be refused an occupancy certificate, denied a home loan, and in the worst cases face demolition. According to Deccan Herald, the government's April 2025 draft notification amended the Bengaluru City Corporation Building Bye-Laws, 2003 to lift the regularisable plan deviation threshold from 5% to 15%.

What is a sanctioned building plan, and who sanctions it in Bengaluru?

A sanctioned plan is the building drawing that an approving authority stamps before construction can legally begin, and in Bengaluru that authority is usually the BBMP (now folded into the Greater Bengaluru Authority), the Bangalore Development Authority (BDA), or the Bangalore Metropolitan Region Development Authority (BMRDA), depending on where the plot falls. The plan locks down the permitted number of floors, the building height, the setback on every side, the floor area ratio, and the approved use, whether residential or mixed. It is issued against a specific khata, survey number and plot area, so a plan sanctioned for one plot cannot legally cover a larger or differently shaped structure. If a seller cannot produce the sanctioned plan and the approving authority's endorsement, treat the property as unverified until they do.

How do you read a sanctioned plan against what is actually built?

You read it by matching four things on the drawing against the physical building: the number of floors, the overall height, the setbacks on all four sides, and the floor area or FAR. Count the floors on the plan, then count the floors on site, including any stilt, mezzanine or terrace room. Measure the open space left around the building and compare it to the setbacks marked on the drawing, because a common trick is to consume the mandatory side and rear gaps to add rooms. The floor area ratio is the ratio of total built-up floor area to plot size, and if you are unsure how it works our explainer on FAR and FSI in Bengaluru walks through the maths. A building that has quietly added a floor or enclosed balconies will show a built-up area well above what the sanctioned FAR allows.

What counts as a plan deviation, and how much does Karnataka tolerate?

A plan deviation is any gap between the sanctioned drawing and the built structure, and Karnataka has traditionally tolerated only about 5%, with the 2025 draft proposing to raise the regularisable band to 15% in Bengaluru. That percentage is measured against sanctioned parameters such as setback, FAR and height, so a minor overrun on a setback may fall inside the band while a whole extra floor never will. It is important to understand what the tolerance does and does not do. It is a limit up to which a violation may be regularised on payment of a penalty, not a licence to build 15% more, and the exact rollout for the Greater Bengaluru Area was still being finalised through official notifications when this guide was written. Compared with the earlier 5% regime, the higher band forgives more genuinely minor errors, but it does nothing for the large deviations that actually sink a purchase.

Why are extra or unauthorised floors the most dangerous deviation?

Extra floors are the most dangerous deviation because they almost always breach FAR and height limits by far more than any tolerance band, which makes them nearly impossible to regularise and the first candidates for demolition. A four-storey block sold as a three-storey sanctioned building means the top floor, and often the flat you are being shown, has no legal existence on the approved plan. Even if every other flat is clean, an unauthorised floor can taint the whole structure's occupancy certificate and stall the entire building's regularisation. Reduced setbacks are the next worst, because they encroach on space meant for light, ventilation, fire access and drainage, and no penalty payment restores that lost margin. These are structural violations, not paperwork gaps, which is why buyers who ignore them tend to discover the problem only when a bank or the civic body does.

How does a plan deviation affect your OC, loan and demolition risk?

A deviation beyond tolerance blocks the occupancy certificate, and without an OC most banks will not sanction a home loan while the building stays exposed to penalty or demolition. The occupancy certificate is issued only when the completed building matches the sanctioned plan within permissible limits, so a major deviation stops the OC at source; our guide on the occupancy certificate and completion certificate in Bengaluru explains how that document gates everything else. Lenders treat the sanctioned plan and OC as core title documents, and as legal commentators such as Sairam Law Associates note, a Supreme Court position has tied civic services to compliance, meaning banks may refuse loans and utilities can be withheld from unauthorised buildings. Karnataka has since offered narrow relief: as Deccan Herald and 99acres report, buildings on plots above 1,200 sq ft within Greater Bengaluru limits, restricted to ground plus two or stilt plus three floors, were given a one-time exemption from producing an OC, though plan approval stays mandatory and B Khata properties are excluded.

What is the seven-point sanctioned plan check before you buy?

The safest approach is to run a fixed checklist before you pay any token, because a deviation is far cheaper to walk away from than to inherit. Work through these seven steps in order.

1. Ask for the original sanctioned plan and the approving authority's sanction endorsement, and confirm the authority is BBMP or GBA, BDA, or BMRDA for that location.
2. Match the survey number, khata and plot area on the plan to the sale documents, so the plan actually belongs to this plot.
3. Count the built floors, including stilt and terrace rooms, against the floors shown on the sanctioned plan.
4. Measure the setbacks left on all sides and compare them with the setbacks marked on the drawing.
5. Check the built-up area and enclosed balconies against the sanctioned FAR to catch overbuilding.
6. Ask whether an occupancy certificate was issued, and if not, why, and whether any exemption genuinely applies.
7. Have your bank's legal and technical valuers inspect before you commit, since their refusal is an early warning the property is deviated.

Is a cheaper deviated building ever worth the risk?

Sometimes the discount is real, but you are buying a legally fragile asset whose price reflects a risk that does not disappear at registration. A deviated building can sell 10% to 20% below a plan-compliant one in the same lane, which is tempting, yet that gap is the market pricing in no OC, harder loans, limited resale, and the standing possibility of a penalty or demolition order. Compared with a neighbouring plan-compliant block, your deviated flat may cost less each month yet trap your capital, because the next buyer will run the same checks and demand the same discount, or walk away entirely. If you still proceed, do it with a full cash view, a lawyer's opinion on regularisation, and clear eyes about the trade-off: you are trading legal certainty for a price cut, and that certainty is what a home is supposed to give you.

Who sanctions building plans in Bengaluru?

Building plans in Bengaluru are sanctioned by the BBMP, now under the Greater Bengaluru Authority, by the Bangalore Development Authority, or by the Bangalore Metropolitan Region Development Authority, depending on where the plot falls. The sanctioning authority fixes the permitted floors, height, setbacks, floor area and use before construction can legally start.

How much building plan deviation is allowed in Karnataka?

Karnataka has traditionally tolerated deviation of about 5% from the sanctioned plan, and a 2025 draft notification proposed raising the regularisable limit to 15% in Bengaluru. This is a band up to which a violation may be regularised on penalty, not permission to build extra, and large deviations like additional floors stay outside it.

Can I get a home loan on a property with plan deviations?

Often you cannot. Banks treat the sanctioned plan and occupancy certificate as core documents, and a major deviation that blocks the OC will usually lead lenders to refuse the loan or demand undertakings. A bank valuer's refusal to clear a property is an early signal that it deviates from the sanctioned plan.

Does a plan deviation mean the building can be demolished?

Large deviations carry real demolition risk. Unauthorised floors and construction into mandatory setbacks generally cannot be regularised, so the civic authority can order the illegal portion removed or levy penalties. Minor deviations within the tolerance band may be regularised on payment, but that relief does not extend to serious structural violations.

Last updated 2026-07-04. PropNewz Team.