Secondary Glazing Guide and Costs

What is secondary glazing?

Secondary glazing on a sash window

Secondary glazing involves installing a pane of glass and frame to existing windows. Unlike double glazing, which would remove a single glazed window and replace it, secondary glazing is added to the existing window.

The purpose of installing secondary glazing is to offer energy insulation and soundproofing to your windows. It is a cheaper solution to double glazing and is a good option if you cannot replace existing windows due to living in period or listed properties.

Although you are technically adding a pane of glass to your existing windows, secondary glazing can be slim and discreet using a strong but lightweight aluminium frame to hold it in place. You can also open and close secondary glazing as you would a normal window.

Secondary glazing is fairly easy to install yourself and can be bought with DIY kits.This will again lower the cost and avoid installation fees as you would have with double glazing.



How much does secondary glazing cost?

The exact cost of secondary glazing will depend on several factors like the number of windows you need to install and the type of window you have. It will also depend on whether your motivation is mainly for noise or draft proofing. Noise reduction proofing requires a particular type of glass which is slightly more expensive.

In comparison to installing double glazing, secondary glazing typically works out cheaper and is quicker to fit. It’s worth getting a few quotes from different installers to find the best deal for you.

The following prices are examples costs for secondary glazing for two window types:

Type of glazing
Cost of noise reduction secondary glazing
Cost of draft reduction secondary glazing
Sash windows
£1057 + VAT
£870 + VAT
Horizontal sliding windows
£894 + VAT
£685 + VAT


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Should I install secondary glazing?

There are 5 factors to consider when choosing whether to install secondary glazing:

  1. You live in a period or grade I or II listed building where you are not permitted to install double glazing.

  2. You cannot get planning permission for double glazing installation. Secondary glazing installation does not require planning permission, and can easily be installed by homeowners themselves.

  3. You want to retain your original windows, and do not want to alter the external look of your building with modern-looking double glazing. Secondary glazing solutions are fit on the interior of the existing window and can come in discreet styles and means of opening for easy access.

  4. You are on a budget. Secondary glazing is considerably less expensive to install than double glazing. This would suit homeowners on a smaller budget who want to conserve energy but require a cheaper solution. You can also reduce costs by fitting the secondary glazing yourself and eliminating installation costs.

  5. You live on a busy road or in a built-up area. Secondary glazing is more effective at reducing noise pollution than double glazing. This is because there is a larger space between the existing window and the secondary glazing which is better at lowering sound levels than the two sealed panes within double glazing which are closer together.

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Secondary glazing for sash windows

Sash window units are a common design feature of period properties. They have two vertically sliding frames made of a single pane of glass and are often poorly fitted.

If you are not keen to replace sash windows with a double glazing, secondary glazing can provide you with a means to retain your original windows but reduce the drafts caused by the poor insulation. They will also help to reduce noise pollution.

Secondary glazing can open in a variety of ways such as horizontal or vertical sliders and hinge units to provide you with easy access.



Magnetic secondary glazing

Magnetic secondary glazing is quick and simple to install but still promises the same insulation and noise reduction benefits as permanent secondary glazing. It also costs less than other secondary glazing solutions.

As the name suggests, this glazing uses magnets to attach to the pre-existing window frame. The magnetic strips are self-adhesive and can match the colour of your window so that you do not see them should you remove and store them during warmer months.

The material used to make magnetic secondary glazing is typically P.E.T. (Polyethylene terephthalate) which is a recyclable plastic.

Magnetic secondary glazing can be attached and removed fairly easily which could come in handy during the summer months. Unlike permanent secondary glazing, they do not have the opening and closing function but must be removed in their entirety to open the window.



Everest secondary glazing

Everest have been in operation since 1965 and produce secondary glazing solutions and installation.

Their frames are made of aluminum and cater for sliding sash windows or hinged systems. Their secondary glazing solutions all come with a 10 year guarantee.

The company scored 57% in the Which? overall customer survey at the time of writing (November 2016). This includes overall satisfaction and likelihood to recommend.



Anglian secondary glazing

Anglian have been manufacturing and installing home improvements for 50 years with their British made products.

They make bespoke secondary glazing for all window styles including sash windows. These can be sliding, tilting or hinged systems.

The company scored 63% in the Which? overall customer survey at the time of writing (November 2016). This includes overall satisfaction and likelihood to recommend.



Clearview secondary glazing

Clearview is a privately owned business which has been designing and manufacturing secondary glazing systems for over 20 years, in the commercial, residential and heritage and listed building markets.

They produce vertical sliding secondary glazing or hinged systems and can also design bespoke solutions for sash windows for heritage or listed properties.

Whilst not individually named in the same customer survey as larger companies, Everest and Anglian, Which? have named Clearview as a trusted trader.


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