PEB Design on American Code vs Indian Codes in India
A practical comparison for engineers, contractors & clients
Pre-Engineered Buildings (PEBs) have become the first choice for warehouses, industries, logistics hubs, showrooms, aviation hangars, and multi-span steel systems in India. While the popularity of PEBs is high, there is one debate that continues across consultants and fabricators:
Should a PEB in India be designed using American Codes (AISC/MBMA/ASCE) or Indian Codes (IS 800/IS 875)?
This blog explains the differences, benefits, limitations, and the ground reality in India regarding PEB design.
1. Why This Debate Exists
Most globally established PEB manufacturers operate using American standards. Their software, design tools, and detailing systems are built around:
• AISC – American Institute of Steel Construction
• ASCE 7 – Minimum design loads
• MBMA – Metal Building Manufacturers Association
• AISI – Cold-formed steel design
Meanwhile, Indian consultants and approval authorities follow:
• IS 800 – General construction in steel
• IS 875 (Part 1–5) – Dead, imposed, wind, snow loads
• IS 801 / 811 / 1161 – Cold-formed sections
This mismatch often creates confusion for clients seeking PEB design solutions.
2. Fundamental Differences between Indian & American Codes
2.1 Design Philosophy
• American Codes: LRFD (Load and Resistance Factor Design)
Uses probabilistic factors to ensure reliability. More refined for steel building design.
• Indian Codes: LSD + Working Stress (older editions)
IS 800:2007 introduced limit state design, but many approvals still consider both philosophies.
American codes are more consistently LRFD/LSD-based.
Result:
American codes generally produce more optimised members for PEB structures.
2.2 Load Calculations
| Load Type | Indian Code | American Code | Key Difference |
|---|---|---|---|
| Dead Load | IS 875-1 | ASCE 7 | Minor variation |
| Live Load | IS 875-2 | ASCE 7 | More detailed occupancy categories in ASCE |
| Wind Load | IS 875-3:2015 | ASCE 7-16 | ASCE has more granular wind pressure zones and directionality factors |
| Seismic Load | IS 1893 | ASCE 7 | ASCE includes more detailed R-factors, drift limits, redundancy factors |
Wind design can vary significantly, leading to a 10–25% difference in section sizes in PEB design.
2.3 Section Availability (Hot Rolled vs Built-up)
• American code provisions are optimised for tapered built-up sections, widely used in PEB building design.
• Indian codes are not as exhaustive for tapered members, though IS 800 allows them.
Result:
Indian designs may be over-conservative for tapered sections unless software (STAAD, MBS, Tekla, RAM) uses advanced checks.
2.4 Cold-Formed Steel
American standards AISI S100 are extremely detailed.
Indian codes (IS 801/811) are outdated and limited.
This is why PEB mezzanine decks, purlins, and girts often use AISI-based design formulas even in Indian projects.
2.5 Serviceability Criteria
• Americans specify tighter limits for deflection, especially for long-span low-rise buildings in PEB design.
• IS 800 allows relatively flexible limits.
Outcome:
American code–designed buildings often feel stiffer and have better serviceability.
3. Practical Ground Reality in India
3.1 Most PEB manufacturers in India use American codes internally
Even for Indian projects, design modules are typically based on MBMA + AISC + ASCE 7.
This is because:
• Software is optimised for these codes
• Easy integration of tapered sections
• Better cold-formed design provisions
• Higher predictability & reliability for PEB structure design
3.2 However, statutory approvals & clients prefer Indian codes
Government bodies, approvals for aviation, fire NOC, factories, industrial safety, and insurance require:
• IS 800 compliance
• IS 875 load compliance
• IS 1893 for seismic
Thus, the PEB manufacturer must map American code outputs to Indian code loadings.
4. Which One Gives a Lighter Design?
American Codes:
Generally produces 10–20% lighter steel tonnage due to optimised LRFD provisions and refined wind design for PEB structures.
Indian Codes:
This often results in heavier sections due to simplified wind zones and conservative assumptions.
5. Which One Is Safer?
Both are safe if used properly.
But the safest option is:
👉 Design using American code (MBMA/AISC) for sections + Apply Indian loads (IS 875 + IS 1893)
This hybrid approach is common and provides:
• Weight optimisation
• Compliance with local laws
• Better reliability for cold-formed members
6. Challenges When Using American Codes in India
• Approval authorities may not understand American standards
• Clients may question the basis of PEB design
• Local engineers may struggle to interpret MBMA/AISC provisions
• Misalignment between American wind maps and Indian wind zones
• Risk of incorrect mapping of load combinations
7. Recommended Approach for PEB Projects in India
Step 1: Load determination → As per IS 875 (mandatory)
Step 2: Seismic loads → As per IS 1893
Step 3: Member design → Using AISC / MBMA for optimisation
Step 4: Cold-formed design → AISI S100
Step 5: Connections → AISC + IS 800 harmonized
Step 6: Serviceability → Stricter of both codes
Step 7: Documentation → Show both compliance sheets
This method ensures compliance + economy + transparency for PEB building design.
8. Conclusion
The debate on American vs Indian codes for PEB design is not about which is better, but which is more practical and compliant.
• American codes provide superior optimisation, detailing clarity, and cold-formed design for PEB structures.
• Indian codes provide mandatory load requirements and approval alignment.
The best practice in India is a hybrid approach—
✔ Indian loading
✔ American member design
✔ Compliance documentation aligning both
This results in safe, cost-effective, and approval-friendly PEB structures.