# Double Glazing Cost Calculator

> Calculate the full cost of double glazing with ROI and payback analysis. Compare uPVC, aluminium, and timber frame prices.

Canonical: https://renoquant.com/double-glazing-cost-calculator
Prices updated: 2026-03

## Double Glazing Pricing and Return on Investment

Understanding the full cost of double glazing helps you make an informed decision. This guide breaks down prices by frame type, window size, and installation complexity, then shows you the long-term return through energy savings.

### Detailed Cost Breakdown by Window Size

| Window Size | uPVC (EUR) | Aluminium (EUR) | Timber (EUR) | Installation (EUR) |
|------------|-----------|-----------------|-------------|-------------------|
| Small (600x900mm) | 200-350 | 350-550 | 450-750 | 60-80 |
| Standard (1200x1400mm) | 350-550 | 550-850 | 700-1,200 | 80-120 |
| Large (1800x1200mm) | 500-800 | 800-1,200 | 1,000-1,800 | 100-150 |
| Bay window (3-panel) | 800-1,500 | 1,200-2,200 | 1,500-3,000 | 200-350 |
| French doors (pair) | 700-1,200 | 1,000-1,800 | 1,200-2,500 | 150-250 |

### 10-Year and 20-Year ROI Analysis

| Scenario | Total Cost | Annual Saving | 10-Year Net | 20-Year Net | ROI % (20yr) |
|----------|-----------|---------------|-------------|-------------|--------------|
| 8 windows, single to double (uPVC) | EUR 4,800 | EUR 300 | -EUR 1,800 | +EUR 1,200 | 125% |
| 8 windows, single to double (Alu) | EUR 7,200 | EUR 300 | -EUR 4,200 | -EUR 1,200 | 83% |
| 12 windows, single to double (uPVC) | EUR 7,200 | EUR 450 | -EUR 2,700 | +EUR 1,800 | 125% |
| 8 windows, old double to new (uPVC) | EUR 4,800 | EUR 90 | -EUR 3,900 | -EUR 3,000 | 38% |

uPVC frames offer the best financial return for most homeowners. Upgrading from single glazing provides a positive return within 15-18 years. When you factor in increased property value (5-10%), the effective payback is even shorter.

### Financing Options Comparison

| Option | Typical APR | Term | Monthly (EUR 5,000) | Total Interest |
|--------|-----------|------|---------------------|---------------|
| Window company 0% finance | 0% | 12-24 months | 208-417 | EUR 0 |
| Green energy loan | 2-4% | 5-10 years | 45-88 | EUR 500-2,700 |
| Home improvement loan | 5-7% | 3-7 years | 70-145 | EUR 700-2,500 |
| Credit card (avoid) | 18-25% | Open | Variable | Significant |

Always compare the total cost of financing with the energy savings over the loan term. A 0% finance deal from the window company is almost always the best option if available.

## Frequently Asked Questions

### How much does it cost to double glaze a 3-bedroom house?

A typical 3-bedroom house has 8-12 windows. With uPVC frames, expect to pay EUR 3,500-7,000 including installation. Aluminium frames cost EUR 5,500-11,000. Timber frames are EUR 7,500-15,000. Prices vary by region and window size.

### Is it cheaper to replace all windows at once?

Yes. Most window companies offer a 10-20% discount for whole-house orders because it reduces their travel and setup costs. Installing all windows at once also means only one period of disruption.

### What financing options exist for double glazing?

Options include 0% finance from window companies (typically 12-24 months), home improvement loans (3-7% APR), green energy loans (often lower rates), and government grants. Some energy suppliers offer interest-free loans for energy efficiency improvements.

### How long do double glazed windows last?

Modern uPVC double glazing lasts 20-30 years. Aluminium frames can last 30-45 years. Timber frames, if well maintained, last 35-60 years. The sealed glass units typically last 15-25 years before the seal may fail and cause condensation between panes.

### Does double glazing increase property value?

Yes. Double glazing typically adds 5-10% to a property's value. It also improves the EPC rating, which is increasingly important for selling or renting. Properties with an EPC rating of C or above attract more buyers and higher offers.

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Interactive version with calculator: https://renoquant.com/double-glazing-cost-calculator. Figures are estimates; final quotes vary by site conditions, materials, and region.