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Glass is typically a constant throughout all buildings, commercial or residential builds are done using a variety of material, bricks, wood, concrete but almost all involve the extensive use of glass.  

Glass can transform a space, it allows natural light in, can keep noise out while protecting against the elements and changing weather throughout the year. The windows in a building can effectively protect against both unwanted heat gain and insulate against heat loss. 

Choosing the right glass enables greater design flexibility to overcome site deficiencies and it’s a great way to provide a comfortable, healthy and energy efficient environment.


By including glazing that offers strong solar control and thermal insulation in your build, you're providing the ability to help balance the temperature in your building. When the right materials are used there is less reliance on the excessive use of heating and cooling systems to control the building temperature. Providing an energy efficiency that can provide both environmental and financial savings. 

Environmental Compliance

As greenhouse gas emissions become a growing concern, the government has developed mandatory minimum Energy Efficiency Measures for both residential and commercial construction.

The code is performance based, offering a number of paths to compliance and setting out the performance that a building has to achieve. In terms of glazing, the key focus is on minimising the rate of summertime heat gain and winter heat loss.

How does it work?

Traditional windows are an energy weak spot in a building’s design, letting heat in during summer and letting warmth escape during winter. Energy efficient glass such as the Viridian products below, act like a plug, letting in light while controlling the flow of heat in and out of your space.

Beating the heat 

Solar heat gain is the increase in thermal energy within a space or object as it absorbs solar radiation. On a technical level, objects hit by sunlight absorb the short-wave infrared components and re-radiate that heat at longer infrared wavelengths. Transparent building materials such as most glass, allow light to pass through  almost unimpeded, though once that light is converted to long-wave infrared radiation it is unable to exit, as glass is opaque to longer wave-lengths.  Which is fine in the cooler months, but can lead to a very uncomfortable living or working environment in the warmer months and increase the reliance on air conditioning systems. 

By utilising energy efficient glass you can help to limit the impact of solar heat gain to keep your space cooler in summer in a less energy-consuming way. Viridian have a number of options available to maximise natural light, typically, toned glass is the most suitable for reducing solar heat gain, though it can also reduce the amount of natural light entering your space. Viridian's energy efficient range includes Solar Control toned glass, absorbing the sun’s heat while still offering high daylight transmission to the inside.

Low-E coated glass products are an alternative option for energy efficient glazing. Low-E is a clear glass which has a special coating on one surface of the glass. Low-E refers to low emissivity and this describes the capacity of a surface to radiate heat. Low-E glass has a microscopically thin, transparent coating (it is thinner than a human hair) that reflects long-wave infrared energy (or heat). Some Low-E windows also reflect significant amounts of short-wave solar infrared energy. When the interior heat energy tries to escape to the colder outside space during the cooler months, the Low-E coating reflects the heat back to the inside, reducing the radiant heat loss through the glass. The reverse happens during the summer. 


Keeping warm

In colder months, solar heat gain is actually desirable. Windows can be positioned to achieve passive solar heat gain and warm your building in winter. Energy efficient glass can also aid in reducing the amount of heat lost through windows during winter, reducing the reliance on heating systems to provide a comfortable temperature. 

Both Low-E glass and double glazed units can greatly improve thermal insulation and in turn, the energy efficiency of your build. Double glazed windows utilize two separate pieces of glass, separated by a vacuum. The vacuum layer acts as an insulative barrier. The glass used can be laminated or UV tinted, but is otherwise similar to the glass used in single glazed windows. In some instances double glazed windows can be up to 100% more efficient than a single glazed equivalent.



The orientation of a building can possibly be the most important consideration of the design process when considering the future features that will be available. It is also an extremely important factor when determining what glass options will be included. 

At the risk of stating the obvious, a building in a cooler climate will have differing needs to a building in a warmer climate. Typically in warmer climates a greater use of energy is used on cooling the space, therefore a glazing option that helps to reduce heat gain is generally more efficient to include. Obviously the opposite applies in cooler climates, where optimizing for the most sunlight hours and choosing a glazing option that helps reduce heat loss is normally preferred. 

North-facing windows can utilise the sun for passive heating during cold winters, receiving twice the winter heating compared to those facing east or west.  In summer, windows facing north and south receive only half the summertime heat of east and west facing glazing. This minimises solar heat gain and is due to the steeper angle of the sun’s path through the sky in summer.

Generally, southern locations will often require products with high performance thermal insulation, while in a northern location, solar radiation will usually be the more critical component.

Click on the links below for product information and further details, or please contact us for assistance. We're human and here to help any way that we can! Thank you to the good people at Viridian Glass for the info. 

SOURCE: Viridian Glass

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