What Happened
- The Union government has withdrawn the revised seismic zonation map and updated earthquake design code (IS 1893:2025) published by the Bureau of Indian Standards (BIS) in late 2025, following strong resistance from multiple Union Ministries and infrastructure sector agencies.
- The revised code had introduced a new highest-risk Zone VI, classifying the entire Himalayan arc for the first time under a single extreme hazard category; it also updated design response spectra and construction standards across all zones.
- Ministries overseeing roads, railways, power infrastructure, and housing raised concerns about a projected 15–30% increase in construction costs that stricter earthquake-resistant design requirements would impose on ongoing and future projects.
- The construction and real estate sector, which had already begun factoring the new code into project planning, expressed concern over cost spikes and project viability — particularly for large infrastructure contracts with fixed budgets.
- The withdrawal reinstates IS 1893:2016 as the operative standard, effectively reverting the official seismic hazard classification to the previous four-zone system while the government reviews the new code further.
What Happened
- The Union government has withdrawn the revised seismic zonation map and earthquake design code (IS 1893:2025) after pushback from multiple ministries and infrastructure agencies.
- Concerns centred on significant cost increases for construction — projected at 15–30% in high-risk zones — rather than the scientific accuracy of the revised hazard assessment.
- The reversal means the entire Himalayan arc, previously reclassified into the new highest-risk Zone VI, reverts to the older Zone IV/V classification under IS 1893:2016.
- Disaster management experts and seismologists warned that economic considerations have been allowed to override scientifically validated risk data, setting a dangerous precedent for infrastructure governance.
- India's buildings and construction sector, which had begun incorporating the new standards, now faces regulatory uncertainty about which code applies to ongoing DPRs and design approvals.
Static Topic Bridges
Bureau of Indian Standards (BIS) and IS 1893
The Bureau of Indian Standards (BIS) is India's national standards body, established under the Bureau of Indian Standards Act, 2016 (replacing the earlier 1986 Act). BIS formulates and publishes Indian Standards (IS) across all sectors — from food safety to structural engineering. IS 1893 (Criteria for Earthquake Resistant Design of Structures) is the primary standard governing seismic design requirements for buildings and infrastructure in India.
- BIS: Under Ministry of Consumer Affairs, Food and Public Distribution
- IS 1893 revision history: First published 1962; major revisions in 1984, 2002, 2016, and the now-suspended 2025 revision
- IS 1893:2025 innovations: New Zone VI; Probabilistic Seismic Hazard Assessment (PSHA) methodology; updated response spectra; soil amplification factors
- IS 1893:2016 (now reinstated): Four zones — Zone II to Zone V; deterministic historical approach
- Seismic zone factor (Z): A design parameter in IS 1893 that determines the lateral force a structure must be designed to withstand; higher zone = higher Z = more steel, stronger foundations, higher cost
Connection to this news: The Centre's withdrawal of IS 1893:2025 means BIS's scientifically updated standard has been suspended due to inter-ministerial and industry pressure — raising questions about the independence and authority of the national standards body in safety-critical matters.
Probabilistic Seismic Hazard Assessment (PSHA)
Probabilistic Seismic Hazard Assessment (PSHA) is the globally accepted methodology for quantifying earthquake risk at a given location. Unlike the older deterministic approach (which simply mapped past earthquake locations), PSHA calculates the probability that ground shaking will exceed a specified intensity level within a given time period — accounting for all possible earthquake sources, magnitudes, and distances.
- PSHA output: Hazard curves showing probability of exceedance for different ground motion levels; used to derive design spectra for building codes
- Global standard: Used by the USA (USGS), Europe (SHARE project), Japan (NIED), and increasingly South Asia
- IS 1893:2025 basis: Generated using PSHA, incorporating updated fault catalogues and attenuation relationships specific to Indian plate tectonics
- Key improvement over old method: Accounts for seismic gaps (regions where large quakes are overdue), fault geometry, and probabilistic occurrence — the older deterministic map could not
- Implication: PSHA-based codes produce more conservative (and safer) design requirements, especially in zones with infrequent but high-magnitude potential events like the Himalayan arc
Connection to this news: The rollback rejects the superior PSHA methodology in favour of an older, less accurate approach — meaning structures built to IS 1893:2016 will be less earthquake-resistant than what the current scientific understanding of Himalayan seismicity demands.
Governance and Policy Trade-offs in Disaster Risk
The withdrawal illustrates a recurring tension in disaster risk governance: the conflict between short-term economic considerations (higher construction costs) and long-term risk reduction (fewer casualties and losses in future earthquakes). International frameworks such as the Sendai Framework for Disaster Risk Reduction (2015-2030) explicitly call on governments to make disaster risk reduction investments economically rational — arguing that upfront mitigation spending is far cheaper than post-disaster recovery and reconstruction.
- Sendai Framework (2015-2030): Global blueprint for disaster risk reduction; India is a signatory; Target E — substantially increase the number of countries with national and local disaster risk reduction strategies
- Cost-benefit of earthquake-resistant construction: Studies show every ₹1 invested in earthquake-resistant construction avoids ₹4-7 in post-disaster reconstruction and economic loss
- India's DRR obligations: National Disaster Management Plan (NDMP) — aligned with Sendai; prescribes mainstreaming disaster risk into development planning including infrastructure design
- Infrastructure ministries' concern: Stricter codes raise costs for national highways, railways, power plants, and housing schemes — all with fixed budget envelopes
- Expert critique: Allowing cost concerns to override evidence-based zoning creates moral hazard — government infrastructure projects will be built to lower safety standards
Connection to this news: The Centre's decision to withdraw the code under ministry pressure is a governance failure that prioritises project cost over public safety — directly at odds with India's stated commitment to the Sendai Framework and evidence-based disaster risk reduction.
Key Facts & Data
- IS 1893:2025: Introduced Zone VI for entire Himalayan arc; used PSHA methodology; now withdrawn
- IS 1893:2016: Reinstated as operative standard; four zones (II to V); deterministic approach
- Projected cost increase from IS 1893:2025 compliance: 15–30% for new construction in high-risk zones
- BIS: National standards body under Bureau of Indian Standards Act, 2016; under Ministry of Consumer Affairs
- Himalayan arc length: ~2,500 km (J&K/Ladakh to Arunachal Pradesh); all reclassified to Zone VI in 2025 revision
- Himalayan fault capability: Long-locked segments capable of M8.0+ earthquakes as per seismological studies
- Sendai Framework (2015-2030): India is a signatory; DRR investment cost-benefit ratio: ~1:4-7
- PSHA: Globally accepted hazard methodology; replaces deterministic historical-epicentre approach
- First IS 1893 publication: 1962; revised 1984, 2002, 2016, 2025 (suspended)