What Glass?

9 years ago
5 minutes

There are a number of factors to consider before you buy an apartment and one of those items is checking what type of glass has been selected by the builder or developer for the apartment. As windows have a lasting impact on the quality of life in any living space, careful consideration of the size, type and placement of windows is required to ensure a comfortable living environment with maximum natural light levels throughout the year.


There are two sets of factors that need to be considered when choosing the right glass for a living space.

The basic factors are climate, location and the orientation of windows.

The four secondary factors which determine the right glass solution are insulation, heat loss and heat gain, ventilation and acoustics.

If an apartment is located in areas that experience colder, longer winters, you need glass that offers better insulation than ordinary glass. Ordinary glass lets your apartment’s heat leak out during cold weather. The best way to insulate windows is to use low emissivity (Low E) glass. This type of glass acts like insulation and significantly improves the energy efficiency of a living space.

Double-glazed windows also offer improved insulation as well as improved noise reduction. For apartments located in warmer climate zones it is also better to use glass that absorbs and reflects the heat such as toned (tinted) glass or toned Low E glass.


Understanding the orientation of the apartment’s windows and how much sun they get throughout different seasons will influence the type of glass needed. To understand what would achieve the best results from window orientation note the following:

  • Achieving a thermally efficient living space can be helped by orientating the apartment’s windows to the north where possible, with eaves or shading to keep the summer sun off the glass.
  • Northerly facing sunrooms capture the best of the sunny aspect without the harshness of the afternoon heat.
  • Most bedrooms should get morning sun; therefore a north-east position would be a good option.
  • The westerly sun as it sets is the most severe in summer and so using a Low E coated glass with a tint in the glass, which makes it appear slightly darker will significantly help keep out that uncomfortable sun load.

Site and surrounding area:

Glass selection should also depend on the site of the apartment. For example, if the apartment is in a high density urban area, an acoustic noise-reducing glass like Viridian’s ComfortHushTM may be required to help reduce unwanted noise.

To address any privacy issues, a translucent glass product like Viridian’s ComfortPlus TranslucentTM is a good option, as it allows natural light to enter the apartment whilst providing privacy at the same time.

The importance of performance glass for Australian properties:

Put simply – no modern apartment should be built with anything less than a Low E glass and preferably with double glazing. The increasing performance requirements associated with building and renovating means there is a growing demand for energy efficient glass. People are also becoming increasingly aware of the impact energy efficient glass can have on the comfort levels and costs of their living environment.

Ordinary windows are an energy leak. A typical, adequately-insulated building that uses ordinary glass can lose up to 49% of heat through the windows in winter. The same windows allow up to 87% of solar heat gain during summer.*

This is where performance glass such as Viridian’s entry-level energy efficiency product SmartGlassTM comes into play. Viridian’s SmartGlassTM works like wall and ceiling insulation, protecting the building from extremes of heat and cold. It offers greater insulation performance, 39% better than ordinary glass, combined with a choice of four levels of solar protection. As it is single glazed it can fit in most standard window frames and whilst it has the same thickness as ordinary glass, its special durable Low E coating improves its insulation significantly over that of ordinary glass.

Double glazing is also now becoming more commonly available and so its pricing has improved significantly. A double glazing product like Viridian’s new LightBridgeTM allows you to mix and match multiple glass types to achieve different performance outcomes.

It’s also important to remember that different windows around a building demand different performance levels, so make sure the apartment has a glazing solution that best meets the building’s various requirements such as sun load and noise control etc. For example, a product like Viridian’s LightBridgeTM is available in two upgrade options, Sanctuary level 1 and Sanctuary level 2. Sanctuary level 1 is a laminated Grade A safety glass. It offers enhanced security, near-complete elimination of UV rays, and a modest level of noise control, and Sanctuary level 2 has all the benefits of Sanctuary 1 but with greatly enhanced noise control. These Sanctuary upgrades help facilitate different window performance levels depending on the specific needs or issues for certain rooms or areas of the apartment.

Benefits of performance glass:

  • Viridian’s entry-level energy efficiency product SmartGlassTM which fits in a standard frame can offer up to 25% savings on heating and cooling bills and greater insulation performance, 39% better than ordinary glass.
  • SmartGlassTM can help properties achieve up to an extra Star Rating in energy efficiency when compared with ordinary glass **
  • Ordinary glass offers little insulation, Low E single glazing such as SmartGlassTM is good, however Low E double glazing like Viridian’s LightBridgeTM is the most effective way to achieve superior insulation.
  • Double glazed products allow you to mix and match multiple glass to achieve different performance outcomes (enhanced noise control, security, etc.)