AHMEDABAD: The Bureau of Indian Standards (BIS) has announced a major revision in the seismic zoning for states across India, elevating Ahmedabad to a higher seismic risk category. The city’s classification has been upgraded from Zone III to Zone IV, a change that will affect the structural design of all new buildings approved after May 2026.
Sources indicate that the new classifications will come into effect on May 3, 2026. Structural engineers will need to ensure buildings can withstand stronger earthquake forces, likely leading to an increase in material usage. Industry experts anticipate a 20-25% rise in the prices of new properties in Ahmedabad.
Experts from the urban development department have marked Ahmedabad as “seismic sensitive.” The city was struck by a catastrophic earthquake in 2001, which claimed over 900 lives and resulted in numerous building collapses.
Officials note that this shift in seismic zoning will greatly impact construction planning and costs in the real estate sector. An anonymous Ahmedabad Municipal Corporation (AMC) official shared, “AMC approves new building plans based on seismic zones declared by BIS. Currently, designs follow Zone III guidelines. However, with BIS’s revision in November 2025, Ahmedabad is now classified under Zone IV, which will directly affect the structural designs of new constructions.”
The official added that the bases, pillars, and supporting elements of new buildings will require more robust specifications. “Stronger designs demand more materials, which will increase the total project costs for new buildings,” the AMC official further explained.
A senior structural engineer, who wished to remain anonymous, confirmed that the changes will necessitate revisions to the structural designs starting from the foundation. “With Ahmedabad’s upgrade to Seismic Zone IV, we must alter the designs of all future projects. Enhanced reinforcement and stronger materials will be required, leading to a projected 20-25% rise in construction costs,” he stated.
Experts from the Urban Development Department noted that the revision is based on IS 1893, the primary Indian Standard that outlines earthquake-resistant design criteria for structures, detailing the minimum design loads and engineering practices necessary to ensure safety during seismic events.
With the BIS formally announcing the implementation date, Ahmedabad’s construction sector has less than a year to adapt to the changes. Developers, structural engineers, and municipal authorities are expected to start aligning new proposals with Zone IV standards ahead of the transition, according to sources.
