Double Glazing Doors & Windows

Maintaining internal lighting & temperature

Windows strongly influence the use of the building and the productivity and comfort of its occupants. The choice of glass has a direct effect on energy consumption in a hospitality venue or building. SANS 204, the South African National Standard for energy efficiency in buildings specifies minimum glazing requirements for all new buildings and building alterations. SABS Standards

The location and placement of windows in your building can dramatically affect your internal lighting and temperature. The type of glass used has a direct effect on heat retention and rejection plus natural light filtration. 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 and similarly, there is specific recommendations for each African country’s climatic zones.

There are a wide range of new glass products and innovations available to improve the thermal performance, as well as the aesthetics, of your building.

Factors to consider regarding the characteristics of glass include:

  1. 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.
  2. The solar heat gain coefficient (SHGC)– keeping harmful rays out and allowing for the correct solar energy absorption.
  3. Visible Transmittance (VT) or Light Transmission – eliminates the need for artificial light by allowing the right amount of light to enter the Building.
  4. The solar optical properties – refers to the transmittance, reflectance and absorption of light.
  5. The air leakage rating
  6. The condensation resistance rating.
  7. Appearance – aesthetic/artistic enhancement.

Useful Information

Bridging The Gap

Glass can bridge the gap between the indoors and outdoors. It also allows visual access to spaces that would not ordinarily be possible both within the building and from the building to the outside environment.

Orientation Of The Building

The solar orientation of the building must be considered when making glass choices.


Performance Optimisation

Glass must be chosen in conjunction with other features like framing, overhangs, awnings and louvers in order that the right combination optimises performance.

Safety & Security

The correct glass can provide added safety and security to your building. It goes without saying that glass installed in buildings must not pose a risk to injury for your guests.

Noise Reduction

Glass can have excellent sound proofing qualities.

Framing Available

Three main types of framing are available Aluminium, wood and PVC.

Installation Requirements

The glass and correct frame choice must be installed properly. There must be no gaps!

Reflective Characteristics

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.

Highly Recommended

Double glazing is highly recommended even in our warmer climate for building glazing. It comes at a premium cost but offers higher performance over single glazing.

Window Composition

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.

Vs. Single Pain Glazing

Double glazing performs better than conventional single pain glazing by improved performance in heat loss and noise transmission.

Incorporation Of Photovoltaic Properties

New technology combines solar energy capture by replacing conventional materials such as glass or ceramics with a constructive material with photovoltaic properties. This new technology can be used in ventilated façades and roofs, curtain walls, skylights etc. The idea is to incorporate photovoltaic properties into the building envelope and allow additional natural energy to be produced from the sun without compromising on the aesthetic value of the building.

Pre-approved Installation Companies (Required)

Glass manufacturers generally do not install glass. Instead, most suppliers have a list of recommended installation specialists.

Recycling Glass

Most glass can be recycled.

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