Windows strongly influence the use of the home and the living experience of its occupants. SANS 204, the South African National Standard for energy efficiency in buildings specifies minimum glazing requirements for all new buildings and building alterations
The location and placement of windows in your home can dramatically affect your internal lighting and the internal temperature. The type of glass used has a direct effect on heat retention and rejection plus natural light filtration. In addition, critical to the overall performance of your glass is the type of frame and quality of installation (SANS 204 specifies requirements on the combined effect of glass and frame). There are specified requirements for each of South Africa’s climatic zones.
There are a wide range of glass products and innovations available to improve the thermal performance, as well as the aesthetics, of your home. Factors to consider regarding the characteristics of glass include:
- The U-Factor – sometimes referred to as U-value or thermal transmittance which addresses the ability of glass to harness and retain heat in differing climatic conditions
- The solar heat gain coefficient (SHGC) – keeping harmful rays out and allowing for the correct solar energy absorption
- Visible Transmittance (VT) or Light Transmission – eliminates the need for artificial light by allowing the right amount of light to enter the home
- The condensation resistance rating
- The solar optical properties – refers to the transmittance, reflectance and absorption of light
- The air leakage rating
- Appearance – aesthetic/artistic enhancement
What you need to know:
- Glass can bridge the gap between the indoors and outdoors. It also allows visual access to spaces that would not ordinarily be possible
- The solar orientation of the house must be considered when making glass choices
- Glass must be chosen in conjunction with other features like framing, overhangs, awnings and louvers in order that the right combination optimises performance
- The correct glass can provide added safety and security to your home
- Glass can have excellent sound proofing qualities
- Three different types of framing are available Aluminium, wood and PVC.
- The glass and correct frame choice must be installed properly. There must be no gaps!
- Try to keep your summer sun out and allow your winter sun in through the use of shading or the reflective characteristic of your chosen glass
- Double glazing is highly recommended even in our warmer climate for residential glazing. It comes at a premium cost but offers higher performance over single glazing
- Double glazing is a window consisting of two glass panes separated by a hermetically sealed air or gas filled space typically between 6mm and 20mm apart. A minimum of 9mm is recommended. The industry standard is a 12mm space.
- Double glazing performs better than conventional single pain glazing by improved performance in heat loss and noise transmission.
- Glass manufacturers generally do not install glass. Instead, most suppliers have a list of recommended installation specialists
- Most glass can be recycled