6063-T5 aluminium and uPVC window systems compared across structural performance, thermal efficiency, lifespan, maintenance and IS compliance for EPC teams specifying large commercial, institutional and infrastructure projects across India.
Get a QuoteFor commercial buildings, hospitals, airports, IT parks and institutional projects in India, the window system specification is a structural and long-term maintenance decision — not just a procurement cost comparison. Aluminium (6063-T5 alloy) and uPVC are the two dominant frame materials specified on large projects. Each performs differently across span widths, wind load zones, thermal requirements and 25-year lifecycle costs.
This guide compares both systems across the criteria that matter to EPC procurement teams, structural consultants and institutional project managers specifying windows for large-scale construction in India.
Aluminium 6063-T5 has a tensile strength of 150–260 MPa depending on temper, enabling slimmer profiles at larger spans. For commercial high-rise towers, airport terminals and large institutional facades, aluminium frames can achieve clear spans of 2.4m+ without intermediate mullions. IS 875 Part 3 wind load compliance is standard across all aluminium systems in Wind Zones III and IV.
uPVC frames rely on internal steel reinforcement for structural performance above 1.2m spans. The reinforcement adds weight and requires galvanised steel inserts that can corrode over time in coastal and high-humidity environments. For large openings — balcony doors, curtain wall systems, hospital corridor windows — uPVC with reinforcement rarely matches the structural efficiency of aluminium.
| Parameter | Aluminium 6063-T5 | uPVC |
|---|---|---|
| Tensile Strength | 150–260 MPa | 40–60 MPa (unreinforced) |
| Max Span (no intermediate) | 2.4m+ | 1.2–1.5m |
| IS 875 Wind Load Compliance | All wind zones | Zone I–II only (unreinforced) |
| Profile Depth (typical) | 45–65mm | 60–70mm |
| Weight | 2.7 kg/m³ (low density) | 1.4 kg/m³ + steel insert |
| Curtain Wall Compatible | Yes — standard system | No |
The Energy Conservation Building Code (ECBC) 2017 sets U-value requirements for fenestration in commercial buildings. Both aluminium and uPVC can achieve ECBC compliance with double glazed units (DGU), but through different mechanisms.
Aluminium conducts heat approximately 1,000 times faster than uPVC, making thermal bridging a consideration in climate zones requiring high insulation performance. This is addressed with thermal break aluminium systems — profiles with a polyamide strip separating inner and outer aluminium sections — which reduce the U-value to 2.0–2.8 W/m²K, comparable to standard uPVC. For most Indian commercial projects in composite and hot-dry climate zones, standard aluminium with DGU meets ECBC requirements without thermal break.
uPVC achieves lower U-values (1.2–1.8 W/m²K) with multi-chamber profiles. For highly energy-sensitive projects — green building certifications, GRIHA 4-star and above, IGBC Platinum — uPVC may be specified for its inherent insulation properties. However, for large commercial facades and high-rise towers, the structural limitations of uPVC typically make aluminium the only viable option regardless of thermal performance.
For projects in Mumbai, Chennai, Kochi, Vishakhapatnam, Goa and other coastal locations, corrosion resistance is the primary material selection criterion.
Aluminium 6063-T5 with anodised finish provides excellent corrosion resistance in marine environments. Anodising creates an aluminium oxide layer 15–25 microns thick that is harder than steel and chemically bonded to the substrate — it cannot peel or flake. For coastal projects, marine-grade anodising (25 microns, Class 25) is specified as standard.
uPVC frames do not corrode, but the galvanised steel reinforcement inserts used in structural applications are susceptible to corrosion in coastal environments. Moisture ingress through poorly sealed frame joints can accelerate reinforcement corrosion, causing frame distortion and seal failure over time. On large projects with hundreds of window units, this becomes a significant long-term maintenance liability.
For institutional procurement teams evaluating total cost of ownership over a 25-year building lifecycle, aluminium consistently outperforms uPVC despite higher initial procurement cost.
| Cost Factor | Aluminium 6063-T5 | uPVC |
|---|---|---|
| Initial Cost (relative) | Higher by 15–25% | Lower |
| Repainting Cycle | None (anodised) / 10–15 yr (powder coat) | N/A — surface fades |
| Hardware Replacement | Minimal — SS hardware standard | Moderate — plastic hardware degrades |
| Frame Lifespan | 40–50 years | 20–25 years |
| Scrap / Residual Value | High — aluminium recyclable | Negligible |
| Coastal Maintenance Risk | Low (anodised finish) | High (steel insert corrosion) |
Aluminium only. Structural span requirements, curtain wall integration and IS 875 wind load compliance make uPVC non-viable. Specify 6063-T5 with anodised or powder coat finish. Aluminium Sliding Windows | Curtain Wall Systems
Aluminium with DGU for acoustic and thermal performance. uPVC may be considered for internal partition windows in low-wind zones only. Specify marine-grade anodising for coastal locations. Aluminium Casement Windows
Aluminium standard — large glazed facades, open-plan floors, curtain wall systems. ECBC compliance with DGU. Green building certifications (IGBC/GRIHA) achievable with thermal break aluminium. Aluminium Sliding Doors
Aluminium for shop fronts, entrance systems and large display windows. uPVC acceptable for back-of-house and service areas only. Aluminium Shop Fronts | Folding Doors
Aluminium with marine-grade anodising (Class 25, 25 micron) is the correct specification for coastal projects. uPVC frames with steel reinforcement inserts are at risk of internal corrosion in marine environments, causing frame distortion over time. Aluminium 6063-T5 with anodised finish has been the standard for coastal commercial projects across Mumbai, Chennai and Goa for over 30 years.
Unreinforced uPVC windows are suitable for Wind Zone I and II only. For Zone III and IV — which includes most of coastal India, the Deccan Plateau and the Northeast — steel-reinforced uPVC is required. For large commercial spans, aluminium 6063-T5 is the standard specification for IS 875 compliance across all wind zones.
Aluminium windows cost approximately 15–25% more than uPVC at initial procurement for equivalent configurations. Over a 25-year lifecycle, aluminium is typically the lower total cost option due to longer frame lifespan (40–50 vs 20–25 years), lower coastal maintenance risk, and residual scrap value. For large institutional projects with 500+ window units, the lifecycle cost advantage of aluminium is significant.
Yes. Aluminium windows with double glazed units (DGU) meet ECBC 2017 U-value requirements for commercial buildings in most Indian climate zones. For highly energy-sensitive projects or GRIHA 4-star and above certifications, thermal break aluminium systems achieve U-values of 2.0–2.8 W/m²K, comparable to multi-chamber uPVC profiles.
All window systems manufactured in 6063-T5 architectural-grade aluminium. Full alloy certification supplied with each order.
Single and double glazed configurations. ECBC-compliant units with U-value documentation for green building submissions.
Full wind load compliance documentation supplied for all systems. IS 875 Part 3 calculations available on request.
Factory supply to all major cities and tier-2 markets. Project coordination for large institutional orders.
Our project team works with EPC contractors and institutional procurement teams to specify the correct aluminium window system for each application. Submit your project requirements for a technical review and quote.
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