The Short Answer
For most residential applications in Chennai — UPVC wins. For large commercial facades, high-rise buildings, and ultra-thin frame aesthetics — aluminium is better. Here's why, with actual data.
Thermal Performance: Critical in Chennai
Chennai summers reach 40°C+ with high humidity. The material that conducts less heat into your home saves money on AC every month for the life of the window.
- Aluminium — thermal conductivity: 160 W/m·K. Excellent conductor. Without a thermal break, it transfers heat directly into your room.
- UPVC — thermal conductivity: 0.17 W/m·K. Nearly 1,000× less conductive than aluminium. Multi-chamber profiles create multiple insulating air pockets.
- Impact: In a typical Chennai apartment, UPVC windows can reduce cooling load by 18–25% vs standard aluminium.
Noise Reduction
For homes near OMR's traffic, airports, or railway lines, acoustic performance matters.
- Single-glass aluminium: 20–25 dB reduction
- Single-glass UPVC: 28–32 dB reduction (better frame seal)
- Double-glass UPVC: 35–42 dB reduction — significant for urban Chennai
Coastal and Humidity Durability
Chennai's coastal air contains salt — a serious corrosion risk for untreated metals.
- Aluminium — requires quality anodising (not just paint). Anodised aluminium handles coastal air well. Cheap powder-coated aluminium corrodes within 5–8 years near the coast.
- UPVC — completely inert. No corrosion, no oxidation, no painting required. Ideal for areas like Besant Nagar, Thiruvanmiyur, and ECR.
Maintenance Over 10 Years
- UPVC: Zero maintenance. Wipe with damp cloth. No painting. No rust treatment. Colour stable for 25+ years (UV-stabilised German profiles).
- Aluminium: Anodised sections need repainting every 5–8 years in coastal areas. Hardware replacement typical at year 8–12.
Cost Comparison (Chennai 2024)
| Parameter | UPVC (German profile) | Aluminium (anodised) |
|---|---|---|
| Standard casement window (3×4 ft) | ₹6,500–₹9,000 | ₹4,500–₹7,000 |
| Sliding window (4×4 ft) | ₹8,000–₹12,000 | ₹5,500–₹9,000 |
| Double-glazing option | +₹1,800–₹2,500 | +₹2,500–₹3,500 |
| Repaint at 7 years | ₹0 | ₹400–₹600 per window |
| 10-year total cost | Lower | Higher (maintenance) |
When to Choose Aluminium Instead
- Very large glass panels (>3m wide) — aluminium's rigidity handles span better
- Shopfronts and commercial facades where ultra-thin sightlines matter
- Curtain wall systems on high-rise buildings
- Folding/bifold doors with structural spans