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New Double Glazed Windows vs Retrofit Double Glazed Windows

New Double Glazed Windows vs Retrofit Double Glazed Windows 

Double glazed windows offer significant improvements over single glazed options in various aspects, including energy efficiency, comfort, noise reduction, and security. The principal benefits of double glazing lie in its structure, which consists of two panes of glass with a space in between, typically filled with an inert gas. This design creates a better insulating barrier against external temperatures, leading to reduced energy consumption for heating and cooling homes. The result is a more comfortable living environment that also contributes to lower energy bills.

However, when considering an upgrade to double glazing, homeowners are faced with a choice: installing new double glazed windows or opting for retrofitting their existing ones. New double glazed windows are a full replacement option and are designed to provide optimum performance in terms of thermal insulation and soundproofing. Their modern locking systems also contribute to enhanced security, which can be especially appealing for residents concerned about break-ins.

Retrofitting existing windows with double glazing involves modifying the current single glazed frames to accommodate a double glazed unit. This can be a cost-effective alternative that still offers improvements in terms of energy conservation and noise reduction. While retrofit may not deliver the same level of performance as new installations, it serves as a viable option for homeowners looking to upgrade without the higher investment of complete window replacement. However, it’s essential to ensure that existing frames are in good condition to support the added weight and requirements of double glazing.

Keep reading to unlock Window Tech’s in-depth guide on new double glazed windows vs retrofit double-glazed windows

About Glazing Technologies

The technology behind the glazing of double glazed windows has evolved to enhance energy efficiency. The standard double glazed window, an insulated glass unit (IGU), typically consists of two panes of glass with an air or gas-filled space in between. Low-emissivity (low-e) glass is a significant advancement, featuring a microscopically thin coating that reflects heat, helping control the climate inside homes.

Another common technology is the use of argon gas, a colourless, odourless, non-toxic gas that is denser than air, filling the space between panes. Argon gas reduces heat transfer through the window, improving thermal performance and energy efficiency.

The panes of glass in the IGU are sealed together, reducing the likelihood of condensation and preventing degradation of the window’s insulative properties. When properly installed with quality materials, the IGU can greatly reduce the need for heating and cooling, leading to lower energy bills.

Comparison of New and Retrofit Double Glazed Windows

When assessing new and retrofit double glazed windows, one should consider their impact on energy efficiency, aesthetics, cost, and durability.

Advantages of New Double Glazed Windows

Energy Efficiency: New double glazed windows often provide superior thermal performance compared to retrofits. They come with state-of-the-art sealing technologies that minimise heat loss and reduce energy bills. The frames are designed to incorporate thermal breaks, enhancing insulation.

Aesthetics: Installing new windows presents the opportunity to update the look of a property. With a broad range of materials and styles available, they can be tailored to improve the property’s aesthetic appeal significantly.

Security: Manufacturers design new windows with robust frames and locking mechanisms to enhance security. They often come with warranties that guarantee their durability over time.

Noise Reduction: By using the latest advancements in glass and frame technology, new double-glazed windows can significantly reduce external noise, creating a quieter and more peaceful interior environment compared to retrofit double glazed windows. 

Disadvantages of New Double Glazed Windows

Cost: The initial investment for new double glazed windows is typically higher when compared to retrofitting due to material and labour costs. Also, the installation process could involve additional construction work to accommodate the new units.

Installation: Installing new double glazed windows can be invasive, often requiring the removal of existing frames. This process can take longer and be more disruptive than retrofitting.


New double glazed windows with a black frame

Advantages of Retrofit Double Glazed Windows

Cost-Effective: Retrofitting existing windows with double glazing can be more cost-efficient as it leverages the existing frames, reducing material and labour costs.

Installation: The process of retrofitting is generally less invasive and quicker than installing entirely new windows, resulting in less disruption to the household.

Thermal Performance: Retrofit double glazed windows can significantly improve thermal resistance of the existing windows, subsequently enhancing energy efficiency and comfort by reducing drafts and heat loss.

Disadvantages of Retrofit Double Glazed Windows

Aesthetics Limitations: Retrofitting is often limited by the aesthetics of the existing frames, which may not be as visually appealing or modern as new frames.

Durability Concerns: Older frames may not provide the same level of durability as new ones, which can affect the longevity and performance of retrofit double glazed windows.

Sealing and Thermal Resistance: While retrofit solutions can offer improved sealing and thermal resistance, they may fall short compared to the comprehensive performance available with new windows designed specifically for double glazing.

Maintenance: Existing frames that are retrofitted may require more maintenance over time than new frames made of modern materials designed for low maintenance and long-term use.

Initial Investment Versus Long-Term Benefits

When comparing the initial outlay for new double-glazed windows versus retrofitting, the former tends to be more costly due to complete window unit replacement. Prices vary depending on factors such as window size, materials, and overall quality. In terms of energy savings, double-glazed windows contain an insulating layer of gas between the panes, providing superior thermal insulation. This can lead to significant savings on energy bills in the long run as they reduce the need for heating in the winter and air conditioning in the summer.

  • New Double-Glazed Windows – AUD 800 – AUD 1,500 per window
  • Retrofit Double-Glazing – AUD 400 – AUD 800 per window

Over several years, the enhanced energy efficiency can offset the initial investment, making double-glazed windows a financially sound choice for homeowners concerned with heating costs and environmental footprint.

Repair and Maintenance Costs

The longevity of new double-glazed windows is typically greater than that of retrofitted ones. As windows age, the sealant can deteriorate, reducing the efficacy of the thermal insulation. The costs associated with repairing and maintaining windows will vary depending on the age and condition of the current frames, as well as the quality of the double glazing.

Retrofitting may require additional changes over time, such as re-sealing or replacing the insulating layer. Regular maintenance of new installations usually involves basic cleaning and occasional painting if wooden frames are used, making them a more reliable option in terms of maintenance:

  • New Double-Glazed Windows:
    • Minor regular maintenance
    • Occasional painting (for wooden frames)
    • Longer intervals before major repairs are needed
  • Retrofit Double-Glazing:
    • Potential for more frequent sealant replacement
    • Possible deterioration of insulating layer sooner than new units
    • More frequent checks to maintain energy efficiency

By choosing new double-glazed units, homeowners may enjoy a decrease in repair and maintenance costs and a prolonged period before any significant deterioration occurs, preserving the home’s thermal efficiency for an extended duration.


An expert installing double glazed windows

Environmental Impact 

New double glazed windows are designed to offer superior energy efficiency over single glazed and older double glazed units. They achieve this by creating a barrier against heat transfer, which ensures that less energy is required to maintain comfortable temperatures inside a building. This reduction in energy use directly correlates to lower carbon emissions, making them an environmentally advantageous choice.

In terms of thermal performance, new double glazing typically features improved sealing technologies and inert gas fills between panes, which enhance insulation. Retrofit double glazed windows, while still beneficial compared to single glazing, may not provide the same level of performance if the existing frames are not as thermally efficient.

Health Benefits

Health benefits of installing new or retrofit double glazing extend beyond thermal comfort. They can effectively block out harmful UV rays, which not only protects the skin but also prevents furniture and fabrics from fading. Furthermore, double glazed units can reduce external noise pollution, which is conducive to lower stress levels and better mental health for those inside.

The comfort of occupants is also a key consideration. Effective double glazing can eliminate cold spots and draughts, contributing to a steady indoor climate. By maintaining consistent temperatures and reducing the need to constantly adjust heating or cooling systems, they can also indirectly promote better health by creating living and working environments that are less prone to causing thermal stress.

Improved air quality is an indirect benefit due to the decreased need for heating and cooling systems, which can circulate dust and other allergens. Both new and retrofit double glazed windows contribute to this aspect; however, newer models may offer more advanced solutions for ventilation that further improve indoor air quality.

A Summary: New Double Glazed Windows vs Retrofit Double Glazed Windows

Aspect New Double Glazed Windows Retrofit Double Glazed Windows
Energy Efficiency Superior thermal performance with state-of-the-art sealing technologies. Improved thermal resistance but may not match new windows’ performance.
Aesthetics Opportunity to update property appearance with a variety of styles and materials. Limited by existing frames, which may not be as visually appealing.
Security Robust frames and locking mechanisms, often with warranties. Depends on the condition and strength of existing frames.
Noise Reduction Significantly reduces external noise with advanced glass and frame technology. Improves noise reduction but may not be as effective as new windows.
Cost Higher initial investment due to material and labour costs. More cost-efficient by leveraging existing frames.
Installation More invasive, requiring removal of existing frames. Less invasive and quicker installation process.

Glazing Technologies

Technology Benefit Mechanism
Low-e Glass Reflects heat, improving climate control Microscopic metallic layer
Argon Gas Filling Reduces heat transfer Denser than air
Insulated Glass Unit Enhances overall insulation Sealed dual-pane system

Cost Considerations and Energy Savings

Type Average Cost Range Energy Savings
New Double-Glazed Windows AUD 800 – AUD 1,500 per window Superior energy savings over time
Retrofit Double-Glazing AUD 400 – AUD 800 per window Significant but potentially less than new windows

Repair and Maintenance Costs

Type Details
New Double-Glazed Windows Minor regular maintenance, occasional painting if wooden frames, longer intervals before major repairs.
Retrofit Double-Glazing Potential for more frequent sealant replacement, possible deterioration of insulating layer, more frequent checks.

Environmental Impact and Health Benefits

Aspect Details
Environmental Impact New double glazed windows offer superior energy efficiency, reducing carbon emissions. Retrofit windows also improve efficiency but may not match new windows.
Health Benefits Both new and retrofit double glazing improve thermal comfort, block UV rays, and reduce noise pollution, contributing to better health and comfort.


Superior Double Glazing by Windows Tech 

Whether you opt for new double glazed windows or retrofit double glazed windows, our team has a winning solution for you.

For over 10 years, Windows Tech has been setting the bar high in Melbourne with top-tier products that are high-quality, energy-efficient, German-engineered, and Australian-compliant

Contact us today to start elevating your home with superior double glazing solutions. 

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Alex Rogovenko

Alex is the driving force behind Windows Tech, a Melbourne-based company renowned for its high-quality, energy-efficient double glazed windows and doors. With a strong focus on personalized services and sustainability, Alex has positioned the company as a leader in the industry, reflecting his modern entrepreneurial vision.