Frequently Asked Questions about secondary Glazing Windows

Secondary Glazing is a slim lightweight aluminium second window that is added to an existing window. Ideal for listed buildings where there are restrictions on changing the windows. Each unit is tailor made for you. Our Secondary Glazing is made to mirror your existing sight lines yet paying close attention to the opening configuration of your existing windows. Each Secondary glazed window is virtually invisible from outside.

The installation of Secondary Glazing is a completely reversible installation that does not change the appearance of the building and can be removed without causing any damage to the fabric of the building and therefore in most cases one is permitted to install it. We would be happy to call or email your conservation officer just to confirm and put your mind at rest that you comply with your local planning authority. Read more about Secondary Glazing for Listed and Heritage properties here.

Secondary Glazing is recommended by both English Heritage and the Listed Property Owners Club.

Face fixing Secondary Glazing units are often the best method for saving space on a window cill, and allows for a small cavity between glass surfaces for increased thermal performance. Depending on the window we may choose to pack away from the primary window in timber surrounds first.

Reveal fixing is achieved by screwing sideways through the aluminium and timber subframe (where required) into the window reveal. This method is more commonly used for acoustic projects where an optimum gap of 70mm - 100mm is preferential. 

If installed correctly to allow for balanced, low level ventilation within the window aperture. Correct levels of air convection between the glass surfaces of the primary window and the secondary glazed panels will allow both internal and external air temperatures to moderate and, as a result reduce the chances of condensation forming from extreme temperature variations.

You must be aware though that Secondary Glazing windows do not act as a de-humidifier in buildings where damp may be a problem through the masonry, nor will it rectify badly insulated primary windows.

All of our Secondary Glazed units are supplied with 4mm toughened safety glass as standard, and are certified in accordance to BS EN 121 50 and for safety up to BS EN 12600 Class 1. Here at Just Secondary Glazing we also offer safety glass options such as laminated and acoustic laminated in various thicknesses where required. All panels are easily removable or open fully in case of emergency. 

Our surveyor will be able to give you a firm idea once they have been measured but as a guide a standard size window can be fitted within an hour. Obviously it depends on the particular job but as a guide an average semi detached home with seven to nine windows could in most cases be installed in one day.

Your new Secondary Glazing Windows are not "off the shelf" and are made to measure for you but we do have fast lead times so depending on the project we aim to install within two to six weeks. Once we have measured up then as well as providing you with a written quotation we can give you a more accurate installation date.

You can either email or phone through your measurements here or our surveyor can pop along at a time convenient to you and measure up. We will then email or post you a free quotation without any obligation. We are a small, specialist business and there are no salesmen and no gimmicky offers. We will give you our best price first time.

No problem, you can email us your questions here and we will respond promptly or even better just give us a call on 0800 8611167