Can existing windows be double glazed?

The most common question our customers ever ask is “can I put double-glazing in my existing windows?” For most people, double-glazing is synonymous with energy efficiency and comfort. The short answer is yes, you can double-glaze many existing windows.

When did houses start getting double glazing?

Double glazing really started to take off in the 1980s and homes started to benefit from improved thermal efficiency, due to sealed and airtight units for both windows and doors. By the 1990s, double glazing in homes had increased from just 16% in the 1970s to over 60%.

What windows did 1930s houses have?

Windows and doors in 1930s houses Single or double storey bay windows are also a common sight. Most incorporated flat windows arranged in a semicircle, although in some cases curved glass and frames have been fitted. Leaded designs were also common.

Does replacing windows add value to home?

Windows are a functional update that are not so noticeable visually, but are much appreciated for improving energy efficiency. A $10,000 expenditure on new windows can bump up an asking price on a house about $8,500, according to, for an 85 percent ROI.

Is it worth replacing old double glazing?

The larger gap between the panes of glass on modern double glazing also makes it more effective at keeping out unwanted noise. So, if you find road traffic, loud neighbours or other sources of noise prevent you from winding down when at home, consider upgrading any old windows.

How long do double glazing windows last?

between 20 and 35 years
The general consensus on double glazing lifespan is estimated to be anything between 20 and 35 years depending on the supplier and the fitter. Others even suggest up to and above 40 years in some cases.

How do I find out how old my house windows is?

It can be etched on the glass surface itself or in the spacers between double-pane windows. If you find a text string like this, write it down as well as any other markings or text you might find. This code will represent the date of manufacture and the maker’s brand. A Google search should verify this information.

Can SLIM double glazing be retrofitted into old windows?

Retrofitting slim double glazing into old windows is more common in Scotland, particularly Edinburgh. In England it is easier to get new windows made but retrofitting is gaining credibility. There are a number of firms specialising in it, including Envirosash, CR Carpentry and Mill House Window Workshop.

How much gap should there be between double glazing windows?

Double glazing that is between 10-15 years old usually has a gap of around 6mm between the two panes of glass. This is significant because the smaller the gap, the less effective the window is at keeping heat inside the home.

What is the average lifespan of double glazing?

The average lifespan of double glazing is 20 years. This can alter to between 10-35 years, dependent on the location of the windows, quality of fitting, materials and temperature. Saving money on fitting new double glazed windows won’t happen overnight.

What is window glazing?

Window glass, called glazing, has come a long way since the days when windows had only a single pane between you and the elements. Today’s energy-efficient windows come with glazing “systems” that incorporate multiple panes of glass, gas fillings, and high-tech, heat-sensitive coatings.