Is secondary glazing and double glazing the same thing?
No, secondary glazing and double glazing are not the same thing. Double glazing involves the installation of a sealed unit that consists of two panes of glass separated by a layer of air or inert gas, such as argon. The sealed space between the panes acts as an insulating barrier, reducing heat transfer and improving energy efficiency. Double glazing is a primary glazing system, meaning it is the primary layer of glass in the window.
Secondary glazing involves adding an additional layer of glass or acrylic to the interior side of existing windows. This secondary glazing panel is separate from the original window and is not hermetically sealed like double glazing. Secondary glazing is considered a reversible solution, as it does not permanently alter the original window and can be removed. This makes it preferable for listed and heritage properties as it does not alter the building’s aesthetic characteristics and allows you to retain the windows’ period features.
What types of windows can I fit secondary glazing to?
Secondary glazing can be fitted to all types of windows, including metal and stone mullions as well as doors with glazed areas (e.g. French doors). Products like Mitchell & Dickinson’s CosyGlazing is particularly effective in sash and casement windows in period and listed properties as it’s completely invisible and highly energy efficient.
Is secondary double glazing worth it?
Secondary glazing can be an excellent way to draught-proof your windows without altering the aesthetic appearance of your property. It is particularly good for listed and period buildings as replacing existing windows with double glazing often isn’t an option due to planning and conservation regulations.
Secondary glazing such as Mitchell & Dickinson’s CosyGlazing also offers a fantastic return on investment and can reduce heat loss in your property by as much as 70%.
Do you need planning permission for secondary glazing?
In most cases, secondary glazing is considered a “permitted development” and doesn’t require planning permission. However, exceptions may apply, especially in conservation areas or for listed buildings. It is best to check with your local planning authority for specific guidelines before commencing any works.
How long does it take to fit secondary glazing?
The installation time for secondary glazing depends on the project’s scope and complexity. Generally, secondary glazing installation is a quicker process than installing new windows.
Will secondary glazing prevent condensation?
Condensation on windows is formed in two ways. The first is caused by warm moist air from the inside touching the cold glass and condensing. This is reduced by secondary glazing, but it’s not guaranteed to stop it completely. The second is caused by external sources of moisture, such as from broken putty allowing rain to leak under each pane of glass and settle on the lower glazing bars. Secondary glazing can trap this water in the void, causing condensation. Therefore, when installing products such as Mitchell & Dickinson’s CosyGlazing, it’s advisable to keep the putty and paintwork in good condition. This will prevent condensation and increase the lifespan of the window.
How much heat is saved by secondary glazing?
Secondary glazing enhances thermal insulation and can reduce heat loss by up to 70%. The amount of heat saved depends on factors like the quality of installation and the type of material used. Mitchell & Dickinson’s CosyGlazing secondary glazing solution is designed to optimise energy efficiency and has a U value of 1.7.
Can secondary glazing be removed and cleaned?
It depends on how the secondary glazing has been attached to your windows. With products like Mitchell & Dickinson’s CosyGlazing secondary glazing you can remove it using suction lifts (which are provided with all their installations). You can then clean your original windows and the CosyGlazing units before attaching them back on.