A building code can be withdrawn in an afternoon. The ground does not read gazette notifications.
That is the quiet lesson of what happened to India's seismic design standard over the last year. In November 2025, the Bureau of Indian Standards notified a revised IS 1893, complete with an updated hazard map and a new highest-risk zone. Within months, it was pulled back. For owners and facility managers, the natural reaction is to relax and assume the pressure is off. In our experience, that is exactly the wrong conclusion, because the case for seismic retrofitting ever depended on which version of the code was on the books this quarter.
Here is the sequence, stripped of the noise. BIS notified IS 1893 (Part 1):2025 in November 2025. It was built on a probabilistic hazard assessment and introduced a new Zone VI for the most hazardous parts of the country, mainly along the Himalayan arc. The Ministry of Housing and Urban Affairs raised concerns about cost, procedure and the level of consultation with states and the construction industry. By a gazette notification dated 3 March 2026, BIS withdrew the 2025 revision and reinstated IS 1893 (Part 1):2016 as the applicable standard.
So as things stand, the 2016 code governs design. The country is back to four seismic zones, II to V, and new buildings are designed accordingly.
That is the regulatory story. The engineering story is different, and it matters more.
Withdrawing a code changes what new designs must satisfy on paper. It does not change a single fault line, soil profile or reinforcing bar in your existing building.
Consider what the debate itself revealed. The seismology community proposed the withdrawn revision because many felt earlier hazard estimates were conservative in some regions. You can disagree about how, when and at what cost to adopt it. You cannot ignore that the scientific conversation pointed toward more demanding ground motions, not fewer. Whatever the final form of the next revision, owners of existing structures should treat the 2016 code as a floor, not a ceiling.
And here is the part that rarely makes headlines. A huge share of India's building stock was designed and built before 2016, many before the 2002 revision, and some before earthquake provisions were seriously enforced at all. Those buildings were never measured against today's expectations, no matter which version you use.
Not every building needs seismic retrofitting with the same urgency. These are the ones we would put at the top of the list:
The most expensive mistake in seismic retrofitting is designing a fix before understanding the building. A sound assessment answers three questions: what the structure is really made of, its condition, and how it will behave under shaking.
In practice, that means working through several layers. As-built information comes first, because old drawings are often missing or no longer match the building. Reinforcement mapping shows where the bars are and their size. Non-destructive tests such as ultrasonic pulse velocity and rebound hammer, along with core testing, reveal the concrete's real strength and uniformity. Carbonation depth and half-cell potential tests show whether corrosion is quietly eating into the steel.
Most people don't realise how much corrosion affects earthquake performance. A corroded bar is not just thinner. It is less ductile, and ductility is precisely what lets a structure deform without collapsing. A building can pass a casual visual check and still be badly compromised in the one property earthquakes test hardest.
Only then does structural analysis make sense, because the model finally gets real material properties instead of assumed ones.
Seismic retrofitting strengthens an existing structure so it performs better under earthquake loading. There is no single method; the right choice depends on the assessment findings. Commonly used approaches include:
Jacketing of columns and beams with concrete or steel increases strength and confinement. Fibre wraps can improve confinement and shear capacity where adding bulk is not practical.
Where the structure lacks stiffness against sideways movement, new shear walls or steel bracing can carry lateral loads and reduce demand on weak members.
You can address soft storeys, abrupt stiffness changes, and poorly connected elements directly so damage doesn't concentrate in one vulnerable level.
There is little point in strengthening a member whose reinforcement is actively corroding. Repair of corrosion damage often has to come before, or alongside, any strengthening scheme.
The best retrofit designs are rarely the most dramatic. They target the specific weaknesses found, with the least disruption to occupants and operations.
A fair question is: retrofit to which standard? With the 2016 code reinstated, that is the current reference for design. But a thoughtful owner will also ask how much margin to build in, especially for critical facilities or buildings in higher zones, given that scientific thinking is moving toward higher demands.
This is a judgement call between the structural engineer and the owner, weighing occupancy, importance, remaining life and budget. Reasonable people land in different places. The point is to make that decision deliberately, with data, rather than by default.
Delaying seismic retrofitting until the "final" code arrives. There will always be another revision. A weak building stays weak while you wait.
Relying on an old certificate. A stability certificate describes the condition at a point in time. Corrosion, changes of use and ageing keep moving after it is signed.
Buying a retrofit scheme before an assessment. Strengthening the wrong element wastes money and can even shift the weakness elsewhere.
Treating it as all or nothing. Prioritised, phased intervention, starting with the most vulnerable elements, is often far more realistic than a complete overhaul.
If you own or manage a building, the practical path is straightforward. Find out the year it was designed and whether its use has changed. Check for visible distress. Then commission a proper structural assessment with NDT and material testing from a team that has an accredited lab and licensed structural engineers behind the report. Let the findings decide whether you need monitoring, repair, retrofit or simply peace of mind.
The code will keep evolving, and the debate over cost and consultation will continue. Meanwhile, your building's condition is a fact you can establish today.
If you are unsure where your structure stands, a conversation with the engineers at Vijna Consulting Engineers is a good place to begin. We would be glad to look at your building and help you work out what, if anything, it needs.
