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Debunking Concerns About VIG Glass

Debunking Concerns About VIG Glass: Main image of listed building with sash windows

Debunking Concerns About VIG Glass

Discover the truth behind VIG Glass! In this comprehensive assessment, we debunk popular myths and evaluate its performance compared to slim double glazing for window upgrades in historic buildings.

A Comprehensive Assessment of Vacuum Glazing compared to Slim Double Glazing


With the increasing interest in energy-efficient windows, VIG Glass (vacuum glazing) has emerged as a potential game-changer. However, it is important to address the concerns and myths surrounding vacuum glazing to gain a clear understanding of its capabilities and limitations. In this article, we will delve into popular misconceptions and provide a comprehensive evaluation of vacuum glazing in comparison to slim double glazing. By debunking these myths, we aim to provide an informed perspective and facilitate well-informed decisions when considering vacuum glazing for window upgrades.

Myth 1: Poor Insulation Values

Myth 2: Dew-Point Shifting and Interstitial Condensation

Myth 3: Compatibility with Georgian Frames

Myth 4: Noticeable Spacers and Potential Delamination

Myth 5: Preservation of Historic Appearance

Myth 6: Environmental Impact and Carbon Footprint

In the following sections, we will explore each of these myths, providing insights into the truth behind them and shedding light on the current state of vacuum glazing. By examining the insulation values, mitigating risks, advancements in design, spacer considerations, balancing preservation and modernization, and sustainability aspects, we aim to present a comprehensive assessment of vacuum glazing. Our goal is to provide you with a clear understanding of the benefits and limitations of this technology, allowing you to make well-informed decisions when considering window upgrades. Let’s separate fact from fiction and explore the world of vacuum glazing in detail.

Section 1: Evaluating Insulation Performance

When considering VIG Glass as a potential glazing solution, it’s important to evaluate its insulation performance. While it is true that the insulation values of vacuum glazing drop towards the edge of the unit, there are still notable benefits to be considered.

An example of a vacuum glazing system with impressive insulation performance is LandVac. With a centre-pane U-value of 0.4W/m²K, LandVac surpasses the insulation capabilities of slim double glazed units. This means that LandVac can provide better thermal insulation, reducing heat transfer and improving energy efficiency.

Comparatively, slim double glazing may experience gas loss over time, leading to decreased insulation performance. The initial insulation values of slim double glazing can deteriorate as the gas between the panes dissipates. In contrast, vacuum glazing systems, such as LandVac, maintain their insulation performance over the long term. This ensures that the desired thermal efficiency is sustained, providing consistent benefits for energy conservation and reducing heating and cooling costs.

While the insulation values at the edges of vacuum glazing units may be lower, it’s important to consider the overall performance of the glazing system. In many cases, the performance of vacuum glazing still outperforms slim double glazed units, offering superior energy efficiency and thermal insulation properties.

It is worth noting that each glazing solution has its own set of advantages and limitations. The suitability of vacuum glazing depends on various factors, such as the specific project requirements, window design, and desired performance outcomes. Therefore, a comprehensive evaluation is necessary to determine the best glazing solution for a particular application.

In conclusion, vacuum glazing, exemplified by LandVac, demonstrates impressive insulation performance with a centre-pane U-value of 0.4W/m²K. While insulation values may decrease towards the edges of the unit, vacuum glazing still outperforms slim double glazed units. The long-term insulation performance of vacuum glazing, coupled with its energy efficiency benefits, positions it as a viable option for improving thermal comfort and reducing energy consumption in buildings.

Section 2: Mitigating Risks of Dew-Point Shifting

Historic buildings present unique challenges when it comes to glazing upgrades, particularly concerning the risks of dew-point shifting and interstitial condensation. These concerns are valid and must be addressed to ensure the long-term preservation of these valuable structures.

One of the key ways to mitigate these risks is through proper installation practices, focusing on effective sealing and insulation. By ensuring a high-quality installation, the potential for moisture penetration can be significantly reduced. This includes sealing any gaps or cracks around the window frames and employing appropriate insulation materials to minimise heat transfer and condensation formation.

However, it is crucial to recognise that addressing dew-point shifting and interstitial condensation requires a holistic approach. Simply sticking to outdated window solutions may not be the most effective strategy for improving comfort and sustainability in old buildings. The goal should be to strike a balance between preserving the historic character of the windows and implementing modern glazing solutions that offer enhanced energy efficiency and thermal performance.

To achieve this, collaboration between experts in historic preservation and glazing technology is vital. By working together, it is possible to develop installation techniques and guidelines that address the specific challenges faced by historic buildings. This may involve customised solutions that consider the unique characteristics of each building, such as its materials, construction techniques, and architectural features.

Moreover, ongoing monitoring and maintenance play a significant role in managing the risks of dew-point shifting and interstitial condensation. Regular inspections can identify any issues early on, allowing for timely repairs or adjustments to prevent moisture-related damage. This proactive approach helps maintain the integrity of the building envelope and minimizes the potential for long-term degradation caused by trapped moisture.

In summary, while concerns regarding dew-point shifting and interstitial condensation in historic buildings are valid, they can be mitigated through proper installation practices, sealing, insulation, and a holistic approach to building upgrades. By collaborating with experts in both historic preservation and glazing technology, it is possible to strike a balance between preserving the architectural heritage and implementing modern glazing solutions that improve comfort, energy efficiency, and sustainability. Ongoing monitoring and maintenance further ensure the long-term preservation of these cherished structures.

Section 3: Advancements in Design and Compatibility

One of the concerns raised regarding vacuum glazing systems is their compatibility with specific window designs, such as Georgian glazing bars. It is important to acknowledge these concerns while also recognising the continuous evolution of technology and design in the glazing industry.

While it may be true that no current vacuum glazing system is perfectly suited for installation in Georgian glazing bars, it is essential to keep in mind that the field of glazing technology is constantly progressing. As demand for more versatile and aesthetically pleasing solutions increases, manufacturers are actively working on developing vacuum glazing systems that can accommodate various window designs, including Georgian frames.

In fact, some emerging solutions already exist that offer promising possibilities for compatibility with Georgian glazing bars. One example is the incorporation of mechanically fixed plant-on glazing bars. This approach allows for the installation of a single pane of vacuum glazing while maintaining the visual appeal and historical integrity of the Georgian windows. With this method, the performance, aesthetics, and security of the windows can be significantly improved, meeting the requirements of both historic preservation and modern efficiency.

By utilising mechanically fixed plant-on glazing bars, the need for complex sightlines and nozzles can be minimized or eliminated. This results in a more streamlined appearance, better integration with the existing window structure, and improved overall performance. Additionally, this approach ensures that the glazing solution can meet the security requirements of modern standards, providing peace of mind to homeowners and building occupants.

While these advancements are still emerging and may not be widely available on the market at this time, it is a clear indication that the industry is actively addressing concerns regarding design compatibility. As technology and design continue to evolve, we can anticipate further progress in developing vacuum glazing systems that seamlessly integrate with Georgian glazing bars and other historical window designs.

In conclusion, while concerns exist about the compatibility of vacuum glazing systems with Georgian glazing bars, advancements in technology and design are continuously being made to address these challenges. The development of mechanically fixed plant-on glazing bars shows promise in providing improved performance, aesthetics, and security. As the industry progresses, we can expect more solutions that offer compatibility with various window designs, ensuring that historic aesthetics are preserved while benefiting from the advantages of vacuum glazing technology.

Section 4: Dispelling Concerns About Spacers

Another aspect of vacuum glazing systems that has raised concerns is the presence of spacers. It is important to understand the role of spacers in maintaining the appropriate distance between the panes in a vacuum glazing unit, as well as address potential issues associated with their design and performance.

Spacers are a necessary component of vacuum glazing systems, as they ensure the proper spacing between the glass panes. They contribute to the overall structural integrity of the unit and help maintain its thermal performance. However, advancements in spacer design have significantly improved their aesthetics and functionality.

One notable example is LandVac, which utilises translucent grey spacers. These spacers are designed to be less noticeable and blend more seamlessly with the surrounding glass. Compared to older designs that may have had more noticeable and distracting colours, the translucent grey spacers in LandVac’s system offer a more visually appealing solution. This allows the focus to be on the clarity and beauty of the glazing rather than on the presence of the spacers.

It is also important to address the rare occurrence of spacers dropping to the bottom of the unit. While this has been reported in isolated cases, it is not a widespread issue with vacuum glazing systems. Manufacturers continuously strive to improve the reliability and durability of their products, including the design and attachment of spacers. The likelihood of spacers dropping to the bottom has been minimised through rigorous quality control measures and technological advancements.

In the case of LandVac, we have observed minimal instances of spacers dropping to the bottom, and it is considered a rare occurrence. Our commitment to providing a high-quality product extends to all components, including spacers, to ensure long-term performance and customer satisfaction.

In summary, while concerns regarding spacers in vacuum glazing systems have been raised, advancements in spacer design, such as the translucent grey spacers used in LandVac, have addressed aesthetic considerations. The rare occurrence of spacers dropping to the bottom of the unit should not overshadow the overall reliability and performance of vacuum glazing systems. By prioritising quality control and technological advancements, manufacturers are continually improving the design and performance of spacers to ensure the long-term integrity of the glazing units.

Section 5: Balancing Preservation and Modernisation

Preserving the character of historic windows is a legitimate concern when considering the adoption of new glazing technologies. It is essential to find a balance between the preservation of architectural heritage and the need for improved energy efficiency and performance. Fortunately, various options are available that aim to address these concerns while meeting modern requirements.

One approach to strike this balance is through the careful selection and implementation of vacuum-insulated glazing systems. While it is true that incorporating historic glass types into vacuum glazing remains a challenge, the focus should be on finding solutions that offer a suitable compromise between preservation and modernization.

By collaborating with expert glazing manufacturers, it is possible to explore alternative designs that maintain the visual integrity of historic windows while incorporating the benefits of vacuum glazing. Through customised configurations and attention to detail, it is feasible to create glazing units that align with the aesthetics of pre-1950s windows.

Moreover, it is essential to consider the broader context of energy efficiency goals and sustainability. Upgrading historic windows with vacuum glazing can significantly improve thermal performance, reduce energy consumption, and enhance occupant comfort. These advantages should not be overlooked when evaluating the potential impact on the character of historic buildings.

Striking a balance between preservation and modernisation requires a nuanced approach. It involves careful consideration of factors such as the specific requirements of the building, the availability of alternative glazing options, and the overall goals for energy efficiency and sustainability. By working closely with preservation experts, architects, and glazing specialists, it is possible to develop tailored solutions that meet the unique needs of historic buildings while ensuring compatibility with modern performance standards.

In conclusion, finding the right balance between preservation and modernisation is essential when considering vacuum glazing for historic windows. While incorporating exact replicas of historic glass types may pose challenges, it is crucial to prioritise the overall energy efficiency and sustainability objectives. By collaborating with experts and exploring alternative designs, it is possible to achieve a harmonious blend of preservation and modernisation that respects the character of historic buildings while embracing the benefits of vacuum glazing.

Section 6: Sustainability and Carbon Footprint Considerations

When evaluating the sustainability and carbon footprint of vacuum glazing, it is important to take a holistic approach that considers multiple factors. While manufacturing location is a valid consideration, its impact on the overall sustainability of vacuum glazing can be mitigated as production facilities may be established closer to the target markets.

Currently, many vacuum glazing systems are manufactured in the Far East, which introduces transportation-related carbon emissions. However, as the demand for vacuum glazing increases, it becomes feasible to establish production facilities in closer proximity to the markets where the glazing is needed. By localising manufacturing, the environmental effects of transporting the units from distant locations can be significantly reduced or eliminated.

In addition to reducing transportation-related emissions, the overall sustainability of vacuum glazing extends beyond the manufacturing location. It is important to consider the entire life cycle of the product, including energy inputs, heat retention, product lifespan, and recyclability.

Vacuum glazing excels in terms of energy efficiency and heat retention, offering substantial reductions in energy consumption for heating and cooling. These benefits contribute to the overall sustainability of buildings, reducing greenhouse gas emissions and the reliance on fossil fuels.

Furthermore, vacuum glazing is designed to be durable and long-lasting, ensuring that it can serve its purpose for an extended period. The longevity of vacuum glazing units reduces the need for frequent replacements, minimizing waste and resource consumption over time.

At the end of their life cycle, vacuum glazing units can be recycled, further enhancing their sustainability. The recyclability of the materials used in vacuum glazing ensures that they can be repurposed rather than ending up in landfills, contributing to a circular economy and reducing the environmental impact.

By considering the potential for localised production and evaluating the energy efficiency, durability, and recyclability of vacuum glazing, we can envision a future where the sustainability of this technology is maximised. As demand increases, the establishment of production facilities closer to the target markets can eliminate or significantly reduce the carbon emissions associated with transportation.

In conclusion, while manufacturing location and transportation are valid considerations, they can be mitigated through the establishment of local production facilities. The overall sustainability of vacuum glazing is driven by its energy efficiency, durability, and recyclability. By embracing vacuum glazing as a sustainable glazing solution, we can reduce energy consumption, minimise waste, and contribute to a more environmentally responsible future.

Section 7: Additional Factors to Consider

When assessing the suitability of vacuum glazing, it is essential to consider additional factors beyond sustainability and carbon footprint. These factors play a significant role in the overall performance and benefits of vacuum glazing solutions.

One crucial factor is the longevity of vacuum glazing. Traditional glazing solutions, such as slim double glazed units, often suffer from decreased performance and potential seal failure over time. In contrast, vacuum glazing is designed to maintain its superior thermal performance and durability for an extended period. The long lifespan of vacuum glazing reduces the need for frequent replacements, resulting in fewer materials consumed and less waste generated, further contributing to sustainability.

Moreover, altering glazing bars to accommodate traditional double glazed units can have a potential impact on security and longevity. Increasing the rebate and reducing the strength of glazing bars may compromise the overall security of windows. In contrast, vacuum glazing, particularly when combined with mechanically fixed plant-on glazing bars, can provide enhanced security levels comparable to modern window systems. This ensures that homeowners can enjoy both the energy efficiency benefits of vacuum glazing and the peace of mind that their windows are secure and durable.

Another crucial consideration is acoustic performance. Homeowner comfort relies not only on energy efficiency but also on reducing external noise pollution. Vacuum glazing, with its multiple panes and advanced sealing technology, offers significant improvements in acoustic insulation. Achieving acoustic ratings as high as 41dB, VIG glass helps create a quiet and tranquil living environment, enhancing the overall comfort and well-being of occupants.

By incorporating these additional factors into the evaluation process, we gain a more comprehensive understanding of the advantages of vacuum glazing. Its longevity ensures a sustainable and long-lasting solution, while its compatibility with existing glazing bars maintains security and architectural integrity. Furthermore, the superior acoustic performance of vacuum glazing contributes to a peaceful and comfortable indoor environment.

In conclusion, when considering vacuum glazing as a glazing solution, it is crucial to take into account its longevity, impact on security and longevity when altering glazing bars, and acoustic performance. These factors complement the sustainability and energy efficiency benefits of vacuum glazing, providing homeowners with a comprehensive solution that enhances their living environment in multiple aspects. By considering these additional factors, we can make informed decisions and prioritise solutions that optimise comfort, security, and sustainability.


In conclusion, this comprehensive assessment has provided valuable insights into the concerns surrounding vacuum glazing and its potential as a glazing solution. We have examined various aspects, from insulation performance and dew-point shifting to design compatibility and sustainability considerations. Through this analysis, we have highlighted the need for informed decision-making and a holistic approach when evaluating glazing options for historic buildings.

While some concerns have been raised, it is important to recognize that vacuum glazing, such as LandVac, offers impressive insulation values, outperforming slim double glazed units. Additionally, the risks associated with dew-point shifting and interstitial condensation can be mitigated through proper installation practices and a comprehensive approach to improving building performance. Advances in design and compatibility are continually being made, with solutions for Georgian glazing bars and mechanically fixed plant on glazing bars showing promise for improved performance, aesthetics, and security.

Furthermore, sustainability and carbon footprint considerations should take into account not only manufacturing location but also the overall energy inputs, heat retention, product lifespan, and recyclability of vacuum glazing. The potential for production to be moved closer to demand, such as in the UK, further eliminates the environmental effects of long-distance transportation.

Moreover, the longevity of vacuum glazing, its impact on security and longevity compared to altering glazing bars, and its acoustic performance are additional factors that contribute to its appeal as a comprehensive glazing solution.

While acknowledging the current concerns and limitations, we remain committed to ongoing research and development. Our goal is to address the identified issues and provide even better vacuum glazing options in the future. We strive to offer solutions that stand the test of time, align with historic aesthetics, and meet the evolving needs of energy efficiency and sustainability.

Informed decision-making, based on a thorough understanding of the pros and cons of vacuum glazing, is essential. We encourage further exploration and collaboration to drive innovation, enhance performance, and ensure the preservation and modernization of historic buildings.

Together, we can shape a future where vacuum glazing becomes a reliable and sustainable choice for upgrading historic windows, striking the perfect balance between preservation and the demands of modern living.