Window Glass & Glazing Types
Originally, windows only had one job, and that was to let light into a building. The first windows were made with pieces of glass held together by lattice leading. Soon after, the invention of thinner and flatter plate glass led to larger squares of glass held together by wooden glazing bars.
Float glass was invented in the late 1950s, allowing for the quicker production of large, flawless glass sheets. This helped the development of more advanced glazing. Double glazing became the norm from the 1970s onwards, as energy efficiency, comfort and security became more important to homeowners.
Installing single glazing is still a requirement on occasion where planning or conservation regulations apply. Along with timber frames, single glazing helps a property retain its period look. To improve insulation under these circumstances we recommend secondary glazing.
Double glazing is one of the most effective ways to improve the insulation of a home, creating a warm and comfortable living environment.
In a double glazed window, two panes of glass are joined by a spacer bar. The gap between the panes traps warm air, slowing the escape of heat from a building. In addition, the best windows introduce an inert gas, such as argon, which further limits the movement of cold air.
In the UK, all new buildings must install at least 1.4 U-value or C rated double glazed windows as standard, but many companies are offering double glazing that can achieve an A or even A+ rating.
Triple glazing contains a third pane of glass, creating an extra cavity which traps warm air and reduces heat loss through the sealed unit.
A common misconception about triple glazing is that the improvement in thermal performance is due to the extra pane itself. However, it's more about the types of glass and coatings used, the gas filled sealed unit and the distance between the panes.
Is triple glazing really any better than double glazing?
Everest triple glazing is one of the highest performing glazing units on the market with an industry-leading lowest U-value making it ultra energy efficient. Choosing energy-efficient Everest windows can help lower your energy bills and reduce your carbon footprint.
If your priority is noise reduction, we recommend noise-reducing double glazing because the middle pane in triple glazing can increase sound vibration and amplify sound transference.
As the Future Homes Standards are introduced, the energy efficiency of a home and U-values for windows will become more important. At Everest, we believe that triple glazed windows will become a requirement in all new build houses as the standards for the fabric structure of buildings keep increasing.
A practical alternative to double glazing for conservation areas
If you live in a listed building or conservation area it may not be possible to replace your windows. In this instance secondary glazing would be the perfect option to reduce noise and cold draughts.
With secondary glazing an additional window installed directly inside of the existing frame. It can help your home achieve thermal, security and noise reduction benefits, whilst remaining invisible to the outside.
Types of glass
New technologies have been developed that make window glass stronger, shatterproof, clearer and quieter. It's important to consider what type of glass would be best suited to your requirements.
Low emissivity glass has an invisible, thin coating applied to its surface that reflects heat. It is strategically placed on the inner pane of glass to help keep heat indoors and to maintain a comfortable temperature.
Low iron glass
Windows that contain low iron glass are noticeably clearer. They allow a higher level of light to pass through compared to older glass types, which sometimes have a slightly green tint.
Security glass is available in a range of sizes and thicknesses depending on your security needs. Typically, laminated glass is 6.4mm thick (compared to 4mm for standard glass), and contains a thin plastic interlayer that prevents the glass from breaking. Toughened glass is up to five times as strong as ordinary glass of the same thickness.
Used as an outer pane in a double glazed unit, this provides an extra level of security to the window as a whole. Toughened glass must also be used for fixed lights in side panels to doors, as well as in windows close to the ground.
Noise reducing glass
Noise reducing glass contains an inner pane that is 6.8mm thick supported by an outer pane that is an incredible 6mm thick. Together, they provide excellent sound insulation. A thin and lightweight solution to noise problems.
Add coloured shapes, patterns and bevelled designs into the glass itself. Decorative glass looks beautiful in top hung fanlights – the top sashes of casement windows – as well as feature windows in halls and stairwells. Coloured glass is similar to stained glass windows, but it doesn't require leading to hold the glass together.
Stylish strips of lead are a purely visual benefit that can be added to your window in order to make it more aesthetically pleasing.
Obscure glass creates a 'cloudy' effect, also known as privacy glass. There's a variety of textures available, such as leaves and flowers, as well as grainy patterns.