As you would expect, double glazing costs more than secondary glazing, as it requires refitting existing windows. If you are bent on saving and have some room to play with, secondary glazing may be your best bet.

How do double and secondary glazing costs compare? If you’re on a budget, secondary glazing can cost up to half the price of double glazing. Of course, prices will vary, depending on whether you’d like sash or horizontal sliding windows, which are cheaper.

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


How can I save on my secondary glazing? You won’t be able to control the style of your windows. But you can pick cheaper frame materials: the lowest cost option is uPVC, with aluminium and wood at the upper end of the scale. You may also want to look at different types of glass – generally speaking, the thicker, the pricier.

The cheapest type of secondary glazing is draft reducing glass, with prices between £685 and £870. Secondary glazing which reduces noise needs more substance, and costs between £895 and £1,057 per pane.


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.


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.


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 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.