When does a building become unsafe? Check rules in Delhi, Mumbai, Bengaluru |

Ageing, unsafe buildings succumbing to the monsoon’s relentless downpour, revealing their vulnerability. AI-generated image

Recent building collapses during the monsoon have once again raised concerns about the safety of ageing residential and commercial structures across India. While cracks in walls, leaking ceilings or visible deterioration may alarm residents, the decision on whether a building is unsafe is governed by municipal laws, structural audits and engineering assessments.A structural audit is one of the key tools used by authorities to determine whether a building remains fit for occupation. However, the rules on when audits are required and what qualifies as an “unsafe” building vary across cities and states.

Delhi

Under Delhi’s building bye-laws, an unsafe building is defined broadly as any structure that is structurally unsound, insanitary, lacks adequate means of escape, poses a fire hazard, or is otherwise dangerous to human life, including buildings that, through inadequate maintenance, dilapidation, or abandonment, become a threat to safety, health, or public welfare.Even an existing approved building isn’t automatically protected from action; the bye-laws allow its continued use only until the Sanctioning Authority forms the opinion that it has become hazardous to occupants or neighbouring property, at which point removal or alteration can be required.Delhi also layers in environmental compliance audits alongside structural ones. For buildings between 5,000 and 20,000 sq. m (Category 1), a self-declaration and certification by a Qualified Building Environment Auditor accompany the permission application, with the local authority incorporating environmental conditions into the permit.For buildings bigger than 20,000 sq. m, a dedicated Environment Cell appraises the project, integrates conditions into the building permission, and requires the proponent to submit a Certificate of Continued Compliance every five years covering energy use, water and waste treatment, and green cover, with penalties and possible auditor blacklisting for false declarations.

Mumbai

Mumbai Municipal Corporation Act (MMC Act, 1888) offers the criteria under different sections for auditing buildings like 354 (Dangerous Structures), 265A (Structural Stability Certificate), 300 (insanitary), 303 (obstructive).Section 264: Ruinous or dangerous structures: A structure (building, wall, parapet, floor, steps, railings, doors, windows, roof, or anything projecting from it) is actionable if it is “in a ruinous condition or likely to fall, or in any way dangerous” to anyone occupying, passing by, or in the neighbourhood. On this finding, the Designated Officer can order the owner to pull down, secure, remove, or repair it — and if the danger is imminent, can act immediately without waiting out the notice period.

Section 265 Periodic inspection duty: Every owner must maintain the building “to prevent its becoming dangerous.” The Commissioner can order periodic inspections; if repairs are found necessary “for the purpose of securing the stability of the structure,” the owner must complete them within two months and certify compliance.Section 265A Structural Stability Certificate: This is the core “structural audit” provision: once a building turns 30 years old (from completion certificate, occupation permission, or 50% physical occupation, whichever is earliest), the owner must get it examined by a registered Structural Engineer and submit a Structural Stability Certificate confirming fitness for human habitation, within a year of that 30-year mark, and every 10 years thereafter (or earlier if the Commissioner directs). Failure to carry out recommended corrective repairs within six months is punishable by a fine.Section 266 Dangerous openings: Any opening in a building situated to “constitute a danger to human life” must be enclosed or barred.Section 300 Insanitary buildings (unfit for human habitation): A dwelling that is “unfit for human habitation and not capable at reasonable expense of being rendered so fit” can be ordered demolished after a hearing before the Standing Committee.Quick heads-up before the details: unlike the Mumbai Act, this BBMP Advertisement Rules, 2021 document isn’t a building-safety law — it’s a hoarding/signage regulation. It only touches “unsafe” or “dangerous” buildings incidentally, as conditions that affect whether an advertisement can be put up.

Bengaluru

Unlike Mumbai’s Municipal Corporations Act, these are construction bye-laws issued under the KTCP Act, 1961, notified by the Karnataka Urban Development Department. They define what “unsafe” means and set a few triggering conditions, but leave the actual enforcement machinery (notices, demolition orders) to the parent Act.Clause 22 — Definition of “unsafe building”Under the definitions clause, a building is “Unsafe” if it:

The bye-laws add a direct consequence: “All unsafe buildings/structures will require restoration by repairs, demolition, or dealing with as directed by the Authority. The relevant provisions of the Act shall apply to the procedure to be followed by the Authority in taking action against such buildings.” — i.e., the bye-law identifies the condition, but the KMC Act/BBMP Act governs how the Authority acts on it.Clause 3.6.4(b) — Land unfit for constructionNo site can be used for construction if the Authority considers it “insanitary or dangerous to construct a building on it.”Clause 3.7 — ReconstructionA building can be reconstructed where it “has ceased to operate due to fire, natural collapse, or demolition having been declared unsafe,” or is likely to be demolished under an Authority order — subject to a certificate from the Authority.Clause 3.8 — Existing approved buildingsContinued use of an already-approved building is protected unless, in the Authority’s opinion, the building is unsafe or constitutes a hazard to adjacent property or to its own occupants — mirroring the Delhi bye-law clause you quoted earlier almost word-for-word.Clause 13.6 — Heritage-listed buildingsReconstruction of a listed heritage building may be permitted when it “is structurally weak or unsafe or has been affected by fire or other calamity,” subject to Heritage Conservation Committee consultation.Across Delhi, Mumbai, and Bengaluru, the core idea stays the same: a building becomes “unsafe” when it threatens human life through structural failure, fire risk, poor sanitation, or blocked escape routes.