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Double Glazed Aluminium Windows Cost in South Africa: Full Price Guide
💰 The complete guide to pricing, specifications, and installation costs for double glazed windows
Let me answer the question I hear more than any other. “How much do double glazed aluminium windows cost?” It’s a fair question – double glazing is a significant investment. And the answer isn’t simple because prices vary dramatically based on specifications: glass thickness, gas fill, Low-E coating, frame type (standard vs thermal break), window size, and installation complexity.
After helping hundreds of homeowners across Gauteng, Western Cape, and KZN price double glazing, I can give you accurate ranges. In this complete double glazed aluminium windows cost guide, I’ll break down double glazing price by specification, compare standard vs premium options, provide provincial pricing, and help you budget for your project. You’ll also learn about insulated glass units and how to get the best value.
For more guidance, read our thermal break guide, single vs double glaze comparison, or energy ratings guide. Ready to understand double glazing pricing? Let’s dive in.
📋 Table of Contents – Double Glazing Price Guide
💰 Double Glazing Cost Overview
Here’s what you can expect to pay for double glazed aluminium windows cost in South Africa.
| Specification | Supply Only (per m²) | Installed (per m²) | Premium vs Standard Single |
|---|---|---|---|
| Standard double glazing (air-filled) | R4,500 – R6,500 | R5,500 – R8,000 | +30% to +40% |
| Argon-filled double glazing | R5,000 – R7,500 | R6,000 – R9,000 | +40% to +50% |
| Argon + Low-E double glazing | R5,500 – R8,500 | R6,500 – R10,000 | +50% to +70% |
| Thermal break frame + double glazing | R7,000 – R10,000 | R8,500 – R12,000 | +80% to +100% |
| Thermal break + argon + Low-E (best) | R8,000 – R12,000 | R10,000 – R14,000 | +100% to +150% |
These prices are for standard window sizes (1.2m x 1.2m – 1.8m x 1.2m). Small windows have higher per m² costs; very large windows have lower per m² costs.
According to Department of Energy double glazing benefits and SANS 10400 insulation standards, double glazing is recommended for energy-efficient homes.
🔬 Cost by Specification – Glass, Gas & Coating
The specification of your insulated glass units dramatically affects price.
| Component | Option | Cost per m² (premium) | Performance Improvement |
|---|---|---|---|
| Gas fill | Air vs Argon | +R200 – R400 | 5-10% better insulation |
| Glass coating | Standard vs Low-E | +R400 – R800 | 15-25% better insulation + UV protection |
| Glass thickness | 4mm vs 5mm/6mm | +R100 – R300 | Slightly better noise reduction, strength |
| Gap width | 12mm vs 16mm | +R100 – R200 | Slightly better insulation (optimal is 16mm) |
| Laminated glass | Standard vs laminated | +R400 – R800 | Security + noise reduction |
Recommended specification for best value: Argon-filled + Low-E coating. This combination provides 80% of the benefit of premium options at 60% of the cost.
Read our single vs double glaze guide for performance details.
🪟 Cost by Frame Type – Standard vs Thermal Break
The frame is as important as the glass for energy efficiency.
| Frame Type + Glass | Installed Cost (per m²) | U-value (W/m²K) | Best For |
|---|---|---|---|
| Standard frame + single glazing | R4,500 – R7,000 | 5.0 – 5.7 | Budget, mild climates |
| Standard frame + double glazing (argon) | R6,000 – R9,000 | 2.5 – 2.8 | Good value for cold climates |
| Thermal break frame + double glazing (argon) | R8,500 – R12,000 | 1.8 – 2.0 | Best energy efficiency, cold climates |
| Thermal break + argon + Low-E | R10,000 – R14,000 | 1.5 – 1.8 | Maximum efficiency, passive solar design |
Which should you choose? Standard frame + double glazing is good value. Thermal break + double glazing is best for energy efficiency. Read our thermal break guide.
📏 Cost by Window Size
Smaller windows cost more per m² due to fixed overheads.
| Window Size (approx) | Area (m²) | Installed Cost (Standard Double) | Cost per m² |
|---|---|---|---|
| Very small (0.6m x 0.6m) | 0.36 | R3,500 – R5,500 | R9,700 – R15,300 |
| Small (0.9m x 0.9m) | 0.81 | R5,000 – R7,500 | R6,200 – R9,300 |
| Standard (1.2m x 1.2m) | 1.44 | R7,000 – R10,000 | R4,900 – R6,900 |
| Large (1.8m x 1.2m) | 2.16 | R9,500 – R14,000 | R4,400 – R6,500 |
| Picture window (2.4m x 1.2m) | 2.88 | R12,000 – R18,000 | R4,200 – R6,300 |
Standard-sized windows (1.2m x 1.2m) offer the best value for double glazed aluminium windows cost.
🗺️ Double Glazing Prices by Province
Double glazing price varies across South Africa due to labour rates, transport, and competition.
| Province/City | Standard Double (Installed per m²) | Thermal Break + Double (Installed per m²) | Notes |
|---|---|---|---|
| Gauteng | R6,000 – R8,500 | R8,500 – R12,000 | Most competitive, many suppliers |
| Western Cape | R6,500 – R9,000 | R9,000 – R13,000 | Coastal-grade recommended |
| KwaZulu-Natal | R6,500 – R9,000 | R9,000 – R13,000 | Coastal-grade recommended |
| Johannesburg | R5,800 – R8,200 | R8,200 – R11,500 | Best prices in Gauteng |
| Pretoria | R6,000 – R8,500 | R8,500 – R12,000 | Similar to Johannesburg |
| Cape Town | R6,500 – R9,500 | R9,500 – R14,000 | Coastal-grade essential within 5km |
| Durban | R6,500 – R9,500 | R9,500 – R14,000 | High humidity requires quality seals |
In Gauteng, you’ll find the most competitive double glazing pricing. Coastal areas add 10-15% for marine-grade protection.
🛠️ Installation Costs – What to Expect
Installation is a significant part of double glazed aluminium windows cost.
| Installation Scope | Cost Range | Includes |
|---|---|---|
| New build (per m²) | R600 – R900 | Fitting into prepared openings |
| Retrofit (replacement, per m²) | R900 – R1,500 | Removal of old windows, disposal, fitting |
| Window removal only (per window) | R300 – R600 | Labour to remove old window |
| Structural modifications (per opening) | R500 – R2,000 | Enlarging openings, lintel work |
Installation timeline: 2-3 days for a typical house (10-15 windows).
Important: Double glazing is heavier than single glazing. Ensure your installer has experience with heavy glass panels.
Read our installation cost guide for more detail.
🏠 Full House Replacement – Realistic Budgets
Here’s what to budget for replacing all windows in different house sizes.
| House Size | Window Area (approx) | Standard Double (Installed) | Thermal Break + Double (Installed) | Premium (TB + Argon + Low-E) |
|---|---|---|---|---|
| Small house (2-bed, 1-bath) | 8-12 m² | R50,000 – R85,000 | R65,000 – R110,000 | R80,000 – R140,000 |
| Medium house (3-bed, 2-bath) | 12-18 m² | R75,000 – R130,000 | R100,000 – R170,000 | R125,000 – R210,000 |
| Large house (4-5 bed, 3+bath) | 18-25 m² | R110,000 – R190,000 | R150,000 – R250,000 | R190,000 – R320,000 |
These are approximate budgets for standard window sizes. Large picture windows, sliding windows, or custom shapes add to the cost.
Use our Pay Later option to manage cash flow for large projects.
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📊 Cost vs Energy Savings – Payback Analysis
Here’s what you can expect to save annually and how long payback takes.
| Upgrade (from single glazing) | Extra Cost (12m² house) | Annual Energy Saving | Payback (Gauteng) |
|---|---|---|---|
| Standard double (air-filled) | R15,000 – R25,000 | R500 – R1,000 | 15-25 years |
| Argon-filled double | R20,000 – R35,000 | R700 – R1,300 | 15-25 years |
| Argon + Low-E double | R25,000 – R45,000 | R900 – R1,700 | 15-25 years |
| Thermal break + double (argon) | R40,000 – R70,000 | R1,200 – R2,200 | 20-30 years |
Important note: Energy savings alone rarely justify double glazing from a purely financial perspective. However, when you add comfort, noise reduction, condensation prevention, and increased home value, double glazing makes excellent sense for long-term homeowners.
For noise reduction or homes on busy streets, the payback is measured in quality of life, not just rands.
Read our soundproof windows guide for noise reduction benefits.
⚠️ Hidden Costs to Watch Out For
⚠️ Warning: These Hidden Costs Inflate Your Double Glazing Budget
Always ask for a detailed breakdown when comparing double glazed aluminium windows cost quotes.
- VAT: Some quotes exclude VAT (15%). Always confirm.
- Removal and disposal of old windows: Often excluded – add R500 – R1,500 per window.
- Structural work: Lintel reinforcement, opening enlargement – add R500 – R2,000 per opening.
- Plaster repairs: After removal, surrounding plaster often needs repair – add R300 – R800 per window.
- Delivery fees: Some fabricators charge R500 – R2,000 for delivery.
- Access equipment: Second-storey windows may need scaffolding – add R2,000 – R6,000.
- Custom colours (powder coating): Standard white/silver included; custom colours add 20-35%.
- Non-standard sizes: Custom size windows add 15-30% to fabrication costs.
- Low-E coating upgrade: Not always included – confirm specification.
- Argon gas fill: Not always included – standard double glazing may be air-filled only.
Read our buying checklist for more.
💎 Cheap vs Premium – Is It Worth the Upgrade?
Here’s the honest truth about double glazing pricing at different tiers.
| Tier | Example Specification | Cost (Installed per m²) | Pros | Cons |
|---|---|---|---|---|
| Budget | Air-filled only, standard frame | R5,500 – R8,000 | Lowest cost, still better than single | Poorer performance, may not meet expectations |
| Mid-range (best value) | Argon-filled + Low-E, standard frame | R6,500 – R10,000 | Good performance, reasonable cost | Frame still conducts heat |
| Premium | Argon + Low-E + thermal break frame | R10,000 – R14,000 | Maximum energy efficiency, best comfort | Highest cost, longest payback |
Our recommendation: Mid-range (argon-filled + Low-E) offers the best value. You get excellent performance without paying for thermal break frames unless you live in a very cold climate (Highveld winters).
Read our brand guide for quality recommendations.
📊 Complete Double Glazing Cost Comparison Table
Use this as your final reference for double glazed aluminium windows cost.
| Configuration | U-value (W/m²K) | Supply Only (per m²) | Installed (per m²) | 12m² House Installed |
|---|---|---|---|---|
| Single glazing (baseline) | 5.7 | R2,800 – R4,500 | R4,500 – R7,000 | R54,000 – R84,000 |
| Double (air-filled) | 2.8 | R4,500 – R6,500 | R5,500 – R8,000 | R66,000 – R96,000 |
| Double + argon | 2.6 | R5,000 – R7,500 | R6,000 – R9,000 | R72,000 – R108,000 |
| Double + argon + Low-E | 2.0 – 2.2 | R5,500 – R8,500 | R6,500 – R10,000 | R78,000 – R120,000 |
| Thermal break + double + argon | 1.8 – 2.0 | R7,000 – R10,000 | R8,500 – R12,000 | R102,000 – R144,000 |
| TB + double + argon + Low-E (best) | 1.5 – 1.8 | R8,000 – R12,000 | R10,000 – R14,000 | R120,000 – R168,000 |
❓ Frequently Asked Questions About Double Glazing Costs
How much do double glazed aluminium windows cost per square metre in South Africa?
Double glazed aluminium windows cost ranges from R5,500 – R8,000 per m² installed for standard units (air-filled), R6,000 – R9,000 for argon-filled, and R8,500 – R12,000 for thermal break frames with double glazing. For a typical 1.44m² bedroom window, budget R7,000 – R14,000 installed. Read our full price guide for detailed breakdowns.
What is the cheapest double glazing option?
The cheapest double glazing price is standard air-filled double glazing with standard aluminium frames: R5,500 – R8,000 per m² installed. However, for marginally more (R6,000-9,000 per m²), argon-filled units offer 5-10% better insulation. The best value is argon-filled + Low-E (R6,500-10,000 per m²) – 80% of the benefit at 60% of the cost of premium options.
Is double glazing worth the money?
For long-term homeowners, yes. While pure energy payback is long (15-25 years), insulated glass units provide comfort (no cold spots near windows), noise reduction (30-35 dB), condensation prevention, UV protection (with Low-E), and increased home value. For homes on busy streets or in cold climates, double glazing is excellent value. For rentals or short-term ownership, single glazing may be sufficient.
How much does it cost to double glaze a 3-bedroom house?
A typical 3-bedroom house has 12-18m² of windows. Double glazing pricing for a full house: standard double R75,000 – R130,000 installed; argon-filled + Low-E R90,000 – R160,000; thermal break + double R100,000 – R170,000; premium (TB + argon + Low-E) R125,000 – R210,000. Use our Pay Later option to manage cash flow.
Does double glazing reduce noise significantly?
Yes – standard double glazing reduces outside noise by 30-35 dB, which is noticeable (a busy street at 70 dB sounds like 35-40 dB inside – quiet conversation level). For maximum noise reduction, use laminated glass (adds R400-800 per m²). Read our soundproof windows guide for more.
What is the difference between double glazing and thermal break windows?
Double glazing addresses heat loss through glass (two panes). Thermal break addresses heat loss through the frame (polyamide strip). For maximum energy efficiency, use both together. Standard double glazing costs R5,500-8,000/m² installed. Adding thermal break frames costs R8,500-12,000/m² installed – 50-70% more but stops frame heat loss. Read our thermal break guide.
How long does double glazing last?
Quality insulated glass units last 15-25 years. The glass itself is permanent; the weak point is the perimeter seal. When the seal fails, moisture enters between panes (fogging). Cheap units may fail in 5-7 years. Look for warranties of 10+ years on the seal. Quality argon-filled units with warm edge spacers last longest.
How do I find a reliable double glazing supplier?
Use ServiceLink SA’s free quote service to find verified aluminium fabricators specialising in double glazing. Ask: What warranty do you offer? (minimum 10 years). Do you use argon gas and Low-E? What is the U-value? Can you provide references? For Gauteng, Western Cape, or KZN, ask for local references. Read our contractor guide.
✅ Final Thoughts: Double Glazing Is an Investment in Comfort
After reading this double glazed aluminium windows cost guide, you understand the investment required and the benefits you’ll receive.
Yes, double glazing is expensive – R6,000-14,000 per m² installed for quality units. But the benefits extend beyond energy savings: year-round comfort, noise reduction, condensation prevention, UV protection, and increased home value.
If budget allows, choose argon-filled + Low-E double glazing with standard frames – the best value combination. For maximum efficiency in cold climates (Gauteng, Free State), add thermal break frames. For tight budgets, standard double glazing (air-filled) still outperforms single glazing significantly.
Don’t buy the cheapest option – cheap double glazing fails prematurely. Invest in quality with good warranties. Your comfort and energy savings will thank you.
Key takeaways for double glazing costs:
- Budget R5,500 – R8,000 per m² for standard double (air-filled) installed
- Budget R6,500 – R10,000 per m² for argon-filled + Low-E (best value)
- Budget R8,500 – R14,000 per m² for thermal break + double (max efficiency)
- Full house (12-18m²): R75,000 – R210,000 depending on specification
- Gauteng offers the most competitive pricing
- Coastal areas add 10-15% for marine-grade protection
- Energy payback: 15-25 years – but comfort and noise benefits add value
- Cheap double glazing fails prematurely – invest in quality (10+ year warranty)
- Argon-filled + Low-E offers the best value for most homeowners
- Use ServiceLink SA to find verified suppliers and compare quotes
Your next step: Ready to invest in double glazing? Get free quotes from verified aluminium fabricators in your area.
Ready to Get Double Glazing Quotes?
Get free, no-obligation quotes from verified aluminium fabricators. Compare double glazed aluminium windows cost options and find the best value for your home.
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📚 Official resources & standards referenced:
- Department of Energy – Double glazing benefits and energy efficiency guidelines.
- SANS 10400 – South African National Standard for insulation standards and building regulations.
Information provided for general guidance. Prices vary by location, specification, and market conditions. Always get multiple quotes for your specific project.
Written by: ServiceLink SA Research Team
Specialist Energy Efficiency & Aluminium Window Experts
The ServiceLink SA Research Team has extensive experience with double glazed aluminium window installations across thousands of South African homes. Our team has worked closely with certified fabricators, energy efficiency specialists, and homeowners to develop this comprehensive double glazing pricing guide. This guide is based on real project data, fabricator quotes, and performance tracking from across Gauteng, Western Cape, KwaZulu-Natal, and nationwide. We update our information regularly to reflect current market conditions and energy standards.
For more information about double glazing, explore our related resources: thermal break guide, single vs double glaze, energy ratings guide, soundproof windows guide, and brand quality guide. Learn about our process on what is ServiceLink SA and read our ServiceLink SA review. Find fabricators in your area: Gauteng, Western Cape, KwaZulu-Natal, Johannesburg, Pretoria, Cape Town, Durban, and Sandton. For related services, see our air conditioning and building construction guides.