Ahmedabad's Ascension to Seismic Zone IV: A New Era of Construction Challenges

The fascination for heights could prove fragile in a place where the earth can shift without warning. Few cities face the ongoing risk of the earth moving beneath them as sharply as Ahmedabad. Ask those who escaped the ravages of the 2001 earthquake here. The energy released was equivalent to 400 atomic bombs dropped on Nagasaki, exploding 23 km below the earth’s surface. Such was the scale of devastation in 2001 that it claimed more than 13,000 lives.

The city has surged upward. Taller towers now dominate Ahmedabad’s skyline. However, a reality lurks beneath the ground. The fascination for heights could prove fragile in a place where the earth can shift without warning. That tension now sharpens, as the Bureau of Indian Standards (BIS) elevates Ahmedabad to a higher seismic-risk zone.

The BIS has delivered a decisive shake-up to Ahmedabad’s construction landscape by revising the country’s seismic zoning. Ahmedabad now moves from Seismic Zone III to the far riskier Zone IV. The change takes effect on May 3, 2026. Every new building approved after this date must follow the tougher seismic design rules. This shift is set to redefine how the city builds and how much it costs to build.

Structural engineers will be compelled to design for significantly stronger earthquake forces, inevitably pushing up material consumption. Industry analysts predict that this shift will drive property prices in Ahmedabad upward by 20 to 25%. Experts in the Urban Development Department describe Ahmedabad as “seismic sensitive,” recalling the city’s devastating earthquake in 2001.

Officials stated that the seismic zone transition would heavily influence construction planning and real-estate project costs. The Ahmedabad Municipal Corporation (AMC) approves building plans strictly according to BIS-declared seismic zones. The base, pillars, and supporting components of all new structures will now require reinforced specifications, which will inevitably increase the quantity of construction material and raise overall project costs.

Another industry analyst observed that the revision would alter the entire structural design from the foundation upward. With Ahmedabad now placed in Seismic Zone IV, every upcoming project will have to be redesigned with heavier reinforcement and stronger structural elements, leading to a 20% to 25% rise in construction costs.

Experts from the Urban Development Department pointed out that the revision draws fully from IS 1893, the principal Indian Standard that lays down the criteria for earthquake-resistant design of structures. This standard specifies minimum design loads and engineering norms needed to ensure that buildings can endure seismic forces safely.

With BIS now formally announcing the implementation date, Ahmedabad’s building ecosystem has less than a year to brace for the transition. Developers, structural consultants, and municipal authorities are expected to begin aligning new proposals with Zone IV norms well before the deadline.

This looming shift comes at a time when Ahmedabad has allowed itself to soar vertically. Rules in Ahmedabad permit very tall buildings. Skyscrapers can exceed 100 metres, which is more than 30 floors. In some high-FSI zones, such as Ashram Road with an FSI of 5.4, buildings can even cross 70 floors and rise above 200 metres. The final height depends on the width of the road and the size of the plot.

The city has already approved many such high-rise projects. Earlier, most tall buildings stopped at around 22 floors or 70 metres. But new policies now push for taller structures, allowing heights of 150 metres and more with special approvals. This trajectory has effectively positioned Ahmedabad as a new skyscraper frontier, now forced to confront the seismic consequences of its own ascent.