Mitchell & Dickinson Secondary Glazing: A Smart Solution for Period Homes

 Maintaining the character of a period property while improving its energy efficiency can be challenging. Many older homes feature beautiful original sash, casement, or other single-glazed windows, but these windows can contribute significantly to heat loss and outside noise. Mitchell & Dickinson secondary glazing offers a practical way to improve comfort and insulation while retaining the appearance and character of original windows.

What Is Secondary Glazing?

Secondary glazing involves installing an additional glazing layer on the inside of an existing window. Unlike replacement double glazing, the original window remains in place. The additional layer creates an insulating space that can help reduce heat loss and improve acoustic performance.

Mitchell & Dickinson has developed CosyGlazing, a bespoke secondary glazing system designed particularly for period and listed properties. The system uses lightweight plexiglass and magnetic fixing strips, creating an unobtrusive solution that can be removed when required.

Why Choose Mitchell & Dickinson Secondary Glazing?

One of the biggest advantages of secondary glazing is that homeowners can improve window performance without replacing original windows. This can be particularly important for heritage properties where preserving historic features is a priority.

Mitchell & Dickinson states that its CosyGlazing system can reduce heat loss through single-glazed windows by up to 70%. The company also says the system can be fitted to different window types while allowing windows to continue opening normally.

Benefits of CosyGlazing Secondary Glazing

1. Improved Thermal Efficiency

Older single-glazed windows can allow considerable heat to escape. Adding a secondary glazing layer creates an additional insulating barrier, helping keep warm air inside during winter.

According to Mitchell & Dickinson, CosyGlazing can reduce heat loss through single glazing by up to 70%, although actual performance depends on the property, existing windows and installation.

2. Reduced Outside Noise

Secondary glazing can also help reduce unwanted external noise. The additional glazing layer and air gap between the original window and secondary pane create another barrier against sound transmission.

This can be particularly useful for properties located near busy roads, town centres, airports or other noisy environments.

3. Preserve Original Windows

For owners of period homes, replacing original windows can change the appearance and character of the property. Secondary glazing allows the original windows to remain in place while improving their thermal performance.

This makes it an attractive option for historic and listed buildings.

4. Suitable for Listed Properties

Mitchell & Dickinson specifically designed CosyGlazing with period and listed properties in mind. The company states that its system is approved for Grade 1 and Grade 2 listed buildings. However, individual properties can have different requirements, so owners should check with the relevant conservation or planning authority where necessary.

5. Virtually Invisible Design

Traditional secondary glazing can sometimes introduce noticeable frames around windows. Mitchell & Dickinson's CosyGlazing system is designed to be much less intrusive.

The company says the system mounts directly onto opening window sashes and can be virtually invisible from both inside and outside.

6. Windows Can Still Open

A major benefit of the integrated system is that homeowners don't necessarily have to sacrifice the functionality of their original windows.

CosyGlazing is designed for different window styles, including sash and casement windows, and Mitchell & Dickinson states that windows can continue to open and close as usual.

Secondary Glazing for Sash Windows

Sash windows are a common feature of Georgian, Victorian and other period properties. Replacing them can be undesirable when homeowners want to preserve their original appearance.

Mitchell & Dickinson's secondary glazing system can be integrated with sash windows. The company describes solutions that allow the sashes to slide while the secondary glazing remains fitted.

This provides a way to combine traditional architectural character with improved modern comfort.

How Does Magnetic Secondary Glazing Work?

CosyGlazing uses magnetic strips to secure the secondary glazing to the existing window. This approach means the panels can be removed when required, including for cleaning.

Mitchell & Dickinson states that suction lifts are provided with installations so homeowners can remove the units and clean both the original windows and secondary glazing panels before replacing them.

What Is CosyGlazing Made From?

The system uses plexiglass, a lightweight and transparent material that provides an alternative to conventional glass. Mitchell & Dickinson describes plexiglass as lightweight, shatter-resistant and suitable for secondary glazing applications.

The material also helps keep the installation relatively unobtrusive while providing an additional insulating layer.

Can Secondary Glazing Help With Condensation?

Secondary glazing can reduce condensation caused by warm, moist indoor air contacting cold glass. However, it does not necessarily eliminate condensation completely.

Mitchell & Dickinson also highlights the importance of maintaining the original window's putty and paintwork because moisture can enter through defects in the building fabric and become trapped within the glazing system.

For this reason, secondary glazing works best when combined with appropriate ventilation and good window maintenance.

Secondary Glazing vs Double Glazing

Both secondary and double glazing can improve thermal efficiency, but they work differently.

Double glazing generally involves replacing an existing window with a sealed unit containing two panes of glass.

Secondary glazing adds another pane inside the existing window while leaving the original window intact.

For modern properties, replacement double glazing may be a suitable choice. For period and listed properties, secondary glazing can be particularly attractive because it can improve performance without removing historic windows.

Is Mitchell & Dickinson Secondary Glazing Worth It?

For homeowners who want to improve the comfort and efficiency of a period property while retaining original windows, secondary glazing can be a highly practical option.

Mitchell & Dickinson combines secondary glazing with other services such as draught-proofing, insulation and window restoration. Its approach is designed around improving the performance of older buildings without unnecessarily compromising their character.

The right solution will depend on factors such as window type, existing condition, property age, conservation requirements, ventilation and the homeowner's insulation and noise-reduction goals.