Are Sash Windows Double Glazed? Enhancing Thermal Efficiency

Call Us Today 07565028004

Welcome to Sash Window Refurbish

Experts in Sash Windows Repair & Restoration, Timber Windows & Timber Doors in east midlands

Why Trust Sash Window Refurbish?

Sash Windows Refurbish specializes in providing repair and restoration services for wooden windows and doors in the UK, as well as various types of carpentry. During the process of fulfilling orders, we utilize a range of tools and paints, including saws, sprays, primers, resins, and adhesives. With more than 20 years of experience in carpentry, we have tested and used various brands and types of work tools, making us well-equipped to offer helpful advice on selecting the right tools and paints for your needs. Read more ...

Can Existing Single-Glazed Sash Windows Be Upgraded to Double-glazing?

One common question homeowners have is whether existing single-glazed sash windows can be upgraded to double-glazing. The answer is a resounding YES. Retrofitting double glazing on wooden windows is a viable option, enhancing thermal performance without compromising the classic aesthetics of sash windows.

Retrofitting Double Glazing on Wooden Windows: What You Need to Know

When considering retrofitting double glazing, it’s essential to understand the process. Wooden windows can be retrofitted with double glazing, provided the frames are in good condition. This upgrade significantly improves insulation, making your home more energy-efficient and reducing heat loss.

Exploring Thermal Imaging in Recent Double-Glazing Projects

Recent advancements in technology have allowed professionals to explore thermal imaging in double-glazing projects. Thermal imaging helps identify areas with heat leaks, ensuring the installation is done with precision. This technology plays a crucial role in optimizing energy efficiency.

Thermal camera testing of our recent double glazing retrofitting projects.

Advantages of Sash Windows Double Glazing: A Comprehensive Overview

Sash windows double glazing offers a multitude of benefits. Apart from enhancing thermal efficiency, it provides excellent external noise reduction, enhanced security, and increased property value. Homeowners seeking a comprehensive solution to their window-related concerns find double glazing an ideal choice.

Double Glazing Options: Single, Vacuum, and Triple Glazing

Understanding the available double-glazing options is essential for making an informed decision. Homeowners can choose between single, vacuum, and triple glazing, each offering varying levels of insulation. Vacuum and triple glazing provide superior thermal efficiency, ensuring your home remains warm in winter and cool in summer.

External Noise Reduction

One significant advantage of double glazing is its ability to reduce external noise. Whether you live in a bustling city or a noisy neighbourhood, double-glazed sash windows create a serene indoor environment. This is particularly beneficial for light sleepers or individuals working from home, providing a peaceful atmosphere.

Enhanced Security

Sash windows double glazing not only improves thermal efficiency but also enhances home security. The modern double-glazing technology makes it significantly harder for intruders to break in, providing homeowners with peace of mind. Reinforced glass and sturdy frames create a robust barrier against unauthorized access.

Increasing Property Value

Investing in sash windows double glazing is an investment in your property’s value. Potential buyers are increasingly aware of the benefits of energy-efficient homes. Upgrading your windows not only improves the aesthetics and functionality of your property but also makes it more appealing to prospective buyers, thereby increasing its market value.

Retrofitting Double Glazing to Wooden Windows: Timeframe and Compatibility

When considering retrofitting double glazing to wooden windows, homeowners often inquire about the timeframe and compatibility of the process. The duration of the project depends on the number of windows being upgraded, with professionals efficiently completing the task within a specified timeframe.

Compatibility, on the other hand, relies on the condition of the existing window frames. If the frames are in good shape, retrofitting double glazing is a seamless process.

Can Double Glazing Be Retrofitted to Any Wooden Window?

Many homeowners wonder if double glazing can be retrofitted to any wooden window. While it’s possible for most windows, unique shapes and dimensions might require custom solutions. Experienced professionals assess the window design and offer tailored retrofitting options, ensuring a perfect fit and optimal thermal performance.

Special Shapes and Dimension Considerations

Sash windows come in various shapes and dimensions, adding character to homes. When retrofitting double glazing to these windows, special attention is given to maintaining their unique design. Professionals use specialized techniques and materials to preserve the original aesthetic while enhancing energy efficiency.

Exploring Alternatives: Secondary Glazing vs. New Double-Glazed Sash Windows

While retrofitting double glazing is a popular choice, homeowners also consider alternatives like secondary glazing or installing entirely new double-glazed sash windows. Each option has its advantages, with secondary glazing being a cost-effective solution and new double-glazed sash windows providing unmatched thermal performance.

Homeowners can weigh the pros and cons to make an informed decision based on their specific needs and budget.

Addressing Common Challenges in Sash Window Double Glazing Projects

Sash window double glazing projects may face common challenges, such as addressing drafts, ensuring a proper seal, or preserving the window’s historical charm. Experienced professionals are equipped to tackle these challenges, employing techniques like weatherstripping and using custom-made seals to maintain the window’s authenticity while maximizing energy efficiency.

Preserving the Charm: Double Glazing in Listed Buildings

Preserving the architectural charm of listed buildings is paramount when considering any modifications. Double glazing can be seamlessly integrated into listed properties, ensuring compliance with historical preservation guidelines.

By using heritage-appropriate materials and techniques, professionals can enhance thermal efficiency without compromising the building’s historical integrity.

Varieties of Double-Glazing Glass

Double glazing comes in various glass types, each offering specific benefits. Low-E glass, for instance, minimizes heat transfer, while laminated glass enhances security. Homeowners can choose the glass type based on their priorities, whether it’s energy efficiency, security, or noise reduction, creating a tailored solution for their home.

Ensuring Window Functionality During and After Reglazing

During the reglazing process, ensuring window functionality is crucial. Professionals take meticulous care to maintain the smooth operation of sash windows. Proper realignment, balancing sashes, and lubricating moving parts are essential steps. Post-reglazing and regular maintenance ensure the longevity and optimal functionality of the windows, providing homeowners with lasting benefits.

Repairing Sash Window Frames: A Crucial Step in Reglazing Projects

Before reglazing, assessing and repairing sash window frames is essential. Damaged or rotting frames compromise the effectiveness of double glazing. Repairing these frames is a crucial step, ensuring a solid foundation for the new glazing. Professionals use specialized techniques and materials to restore the frames, guaranteeing the durability of the entire system.


How Does Double-Glazing Work?

Double glazing works by trapping a layer of air or gas between two panes of glass. This trapped layer acts as an insulator, reducing heat transfer between the interior and exterior of the building. This process significantly improves thermal efficiency, keeping homes warm in winter and cool in summer.

What Is the Lifespan of Double Glazing?

The lifespan of double glazing depends on various factors, including the quality of materials, installation, and maintenance. Generally, well-maintained double glazing can last for 20 to 25 years or more. Regular inspections and timely repairs ensure its longevity, providing homeowners with enduring benefits.

Distinguishing Between Secondary Glazing and Double Glazing

Secondary glazing involves adding a pane of glass to existing windows, creating a double-glazed effect. While it offers some insulation benefits, it is not as effective as primary double glazing.

Can old sash windows be double-glazed?

Yes, old sash windows can be double-glazed, but they require careful retrofitting to maintain their aesthetic appeal and functionality. Specialized techniques and materials can be used to add double glazing to existing sash windows, improving energy efficiency and insulation.

Can wooden sash windows be double-glazed?

Wooden sash windows can also be double-glazed. Double glazing involves adding a sealed unit with two panes of glass to the existing window frame, providing better insulation. This process can be applied to wooden sash windows, enhancing their energy efficiency without compromising their traditional appearance.

About the author

Glen Ramsey, who presently holds the positions of customer support and content manager, is a cherished member of the Sash Window Refurbish team. He is in a unique position to provide advice on all questions pertaining to the renovation of historic windows because he has a wealth of experience in all elements of window renovation, dealing with clients regularly and assisting them in choosing the best window-related course of action. He oversees the creation of information for all of our platforms in his capacity as content manager, including web content and other materials. Glen has witnessed the whole gamut of Sash Window Refurbish's window restoration activities, from our work on significant listed Georgian homes to a wide variety of smaller-scale private residential projects.


My technician Andrew replaced all my sash windows that had rotten sills. Accessing the rotten sills was not an easy task. He explained to me what needed to be done in order to fix the problem. He is a great person and I’m happy that he was the one who did the job. He is reliable, tidy, friendly and very professional. I highly recommend him.



I hired Andrew and Alex a while back to repair my damaged sash windows. They were was very considerate and very patient as he did his job. A few days ago, I had another problem with one of my sash lock keys and I called him again to come and fix the problem. I’m very impressed that Liam responded quickly and he not only fixed the problem but he also gave me a spare key. What a great after sales service!

Alan W.


I’m very impressed with the new windows that Andrew installed and also the reconditioning job that he did on other sash windows. The quality of his work is by far more superior than what we got when we hired another company a few years back. We will certainly hire him again if any window work arises

Kelly (Sleaford)


Our decorator referred us to Andrew because some of the work needed a window expert. Andrew together with our decorator did a fantastic job. The work was done efficiently and to the highest standards. Andrew is understanding, committed and very professional. I recommend him without any hesitation.

Steaven Reader


Alex did a great job in fixing windows in our terraced house. The windows were broken, frames damaged and the wood was also rotten. Alex's job was high quality and he did it pretty fast. I was also very impressed that he was considerate of my son’s asthma condition and maintained cleanliness. Top work.



Andrew just recently replaced three sash windows in my Edwardian house. He also repaired and replaced some sills and draught proofed three windows. In addition to that, he also did some carpentry work. What I like the most about Liam is that he did a clean job. He is very professional and always updated me about the timescales and costs. He also did his job with minimal disruptions. I highly recommend him.

Cris M.