History and Development of Double Glazing
Although the exact history of double glazing is somewhat difficult to trace, it is commonly believed that the technology originated in Scotland in the Victorian era and made its way to the United States in the 1930s.
A century ago, heat energy was even more expensive in the UK than it is today.
Early origins:
Residents of draughty Victorian properties in Scotland often relied on one heat source, usually a fire in the kitchen, during the winter.
Cold draughts blowing through single paned windows were an unfortunate part of Scottish wintertime life. Anyone who has spent a winter in Scotland can easily understand why people back then were eager to invent more energy efficient windows!
Double glazing technology made its way from Scotland to America in the 1930s, where it was trademarked by an inventor named C. D. Haven. Mr. Haven named his windows ‘Thermopane’ and began to promote them through a company called the Libby Owens Ford Glass Company. Thermopane windows were quite popular in the United States over the next two decades; some elderly Americans still recall a time when having Thermopane windows installed in a home was the height of sophistication.
Popularity in the UK:
Although double glazing as a building technique has been around for about eighty years, homes and businesses in the UK rarely chose to install double glazed windows until about forty years ago. Starting in the 1970s, however, double glazed windows quickly grew in popularity in the UK.
There are a few reasons why it took so long to catch on in the UK. First, building codes in the UK before the 1970s were much less strict. Pre-1970s building codes did not place nearly as much emphasis on energy efficiency as they do today, so homebuilders and homeowners had little motivation to improve the energy efficiency of their homes.
Secondly, suitable materials before the 1970s were much more expensive than they are today. With the development of economical aluminium window frames in the 1970s, the cost of replacement windows came down dramatically and came quickly within the financial reach of a good number of UK homeowners. The later developments of uPVC as a building material further reduced the cost of replacement windows.
Thirdly, the energy crisis of the 1970s shocked many UK citizens into reconsidering the way they used energy. In 1973, members of the Organization of Arab Petroleum Exporting Countries (OAPEC) declared an oil embargo in response to the United States’ support of Israel during the 1973-74 Yom Kippur War. OAPEC’s embargo severely restricted the supply of oil to the US and Western Europe, causing consumer panic. Suddenly, the UK had to confront its dependence on foreign oil.
Many newly energy-conscious homeowners in the UK decided to reduce their dependency on heating oil by installing the new, more efficient window technology. The Yom Kippur war may have been an international relations nightmare, but it did a lot to raise awareness of the benefits of double glazing in the UK!
Double glazing today:
In the UK now, double glazing is a standard feature in most new homes and an increasingly popular retrofit option for older homes. A growing number of homeowners in the UK are also installing double glazed windows in conservatories or the orangery. It’s estimated that UK residents now spend about £3,000 million a year on replacement windows for their homes or businesses.
Recent changes to environmental regulations in the UK have further enhanced the appeal of double glazing for many homeowners. The Energy White Paper, the Code for Sustainable Homes, and the introduction of Home Information Packs are a few examples of government initiatives that will likely enhance demand in the UK in future years.
The double glazing industry:
As the popularity of double glazing has spread across the UK, the number of installation companies has also grown. Small family-run companies to large national chains all offer installation services. The vast array of replacement window installation companies now operating in the UK mean that homeowners have more choice than ever when selecting a contractor.
However, with numerous glaziers competing for installation contracts with homeowners, some companies have unfortunately resorted to high-pressure sales tactics to promote their services. In recent years, the industry in the UK has developed something of a negative reputation due to the irresponsible sales practices of some contractors.
In order to protect homeowners and restore the industry’s reputation, several industry associations and watchdog groups have been formed in recent years. The main industry body for double glazing contractors is the Glass and Glazing Federation (GGF). GGF members not only install replacement windows but also work with any kind of flat glass or architectural glass products.
The Fenestration Self Assessment Scheme or FENSA, is another organization within the Glass and Glazing Federation. (‘Fenestration’ comes from the Latin word for window, ‘fenestra’).
Contractors who are FENSA members can issue certificates to homeowners testifying to the quality of their work. In addition, windows installed by a FENSA contactor come with a 5-10 year guarantee.
Finally, the Double Glazing and Conservatory Ombudsman Scheme (DGCOS) offers protections to homeowners quite similar to FENSA’s guarantees. The DGCOS also offers ombudsman dispute resolution service to homeowners who are dissatisfied with their contractors for any reason.
The history of double glazing is long. The technology made its debut in draughty Victorian properties in Scotland over a century ago, traveled to America in the 1930s, gained popularity in the UK in the 1970s on the back of environmental regulations and the Arab oil crisis.
Double glazing is now a common home improvement choice in the UK, and the industry has grown remarkably in recent years. UK homeowners now have more choice than ever when it comes to installing replacement windows in their properties and enjoy a high standard of industry protection and regulation.


