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Do I need double glazing in my new house?

The historical norm throughout South Africa when it comes to windows and glazed products is to use a single layer of glazing. Over the past few years, this has started to change. Recent legislation has also brought about some drastic changes to the legal requirements for glazed products and this has had a particularly large effect on new buildings in the Garden Route area as well as elsewhere in the Southern Cape. Clients are often surprised when they hear about a requirement for double glazing in their new home and this article aims to clear up some of the confusion around double glazed windows.

Since 2011, South Africa has had mandatory energy efficiency regulations in place for all new buildings in the form of SANS10400-XA which sets requirements for many different parts of a new building, including glazing. Although the enforcement of the legislation was patchy at first, the general legal requirement for windows in residential buildings throughout South Africa became single glass panes with a low-E coating, which is a special kind of factory-applied treatment that improves the insulation value of the glass. In some cases, houses with an unusually large amount of glazing have been required to use double glazed windows instead, which is a type of window that incorporates two separate panes of glass separated by an air gap.

In November 2021, the South African government gazetted an updated version of the SANS 10400-XA regulations. There was a six-month transition period and, although enforcement is still somewhat patchy, the current legal requirement is quite different from the previous one, especially if you are building a house in the Southern Cape. This includes Garden Route areas such as Plettenberg Bay, Knysna, George, and Mossel Bay. The new regulations define a special zone known as the Southern Cape Condensation Problem Area, which stretches all the way from Malmesbury and Tulbagh in the west to Port Alfred in the east and remains south of the mountain ranges. The rules for glazing in this area, as defined by the legislation, differ considerably from those in the rest of South Africa. The biggest difference is that single low-E glass is no longer legally allowed to be used in this area, meaning that the vast majority of new houses, unless they have a very small window area, now need to use double glazing in order to comply with the requirements.

Double glazing is considerably more expensive than single glazing, which is why a lot of people try to get around this requirement. Many local glazing installers aren't even aware of the legal regulations which their installations need to comply with. As such, it is not uncommon to see houses still being built with single glazing, but the homeowners are taking a huge risk because the municipalities can refuse to issue an occupation certificate for newly built houses that do not comply with these requirements.

Despite the obvious drawback of higher costs, it is also important to understand why these requirements have been put in place. The Garden Route's coastal climate often brings high humidity levels and condensation issues, particularly during colder months. Single-glazed windows are prone to condensation formation and low-E coatings actually worsen this problem. It results in moisture-related problems such as mould growth and deterioration of window frames as well as damage to curtains, floors, paint, etc. Double glazing helps to combat condensation by maintaining a warmer inner pane, reducing the likelihood of moisture build-up. By controlling condensation, double glazing protects the integrity of your windows and preserves the air quality within your home.

Double glazing also has a number of other noteworthy advantages. With two panes of glass separated by an insulating layer of air, double glazing significantly reduces the transfer of heat through windows, helping maintain a consistent indoor temperature. This improved thermal insulation also leads to long term savings on electricity costs, as it reduces the need for excessive heating or cooling. If you want to run your house off a solar energy system, which has become very common due to load shedding, the savings can be immediate because the reduced need for artificial heating and cooling makes it feasible to install a much smaller and less expensive solar energy system. In addition, double glazing also acts as a barrier against external noise, reducing its transmission significantly, and it aligns well with principals of environmental sustainability.

For new homes in the Garden Route area, double glazed windows are now the normal legal requirement and embracing the benefits of double glazing is a smart choice. The improved thermal insulation, noise reduction, condensation control, energy efficiency, and environmental sustainability offered by double glazing contribute to a more comfortable, eco-friendly, and cost-effective living experience. As you embark on creating your dream home, make the wise investment in double glazing, and let the beauty of the Garden Route blend harmoniously with your living space.



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