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Low E Double Glazing in Christchurch

What is Low E Glass?

Low Emissivity (Low E) Glass

Windows can reflect, take in, and transfer heat, so Low E coatings can be used to enhance the performance of a window.

Low E is a common abbreviation of “Low Emissivity”. Low Emissivity means a surface that gives off low levels of radiant heat. Therefore, a glass window with a Low E coating will reduce the amount of heat transfer, making your house warmer in the winter and cooler in the summer.

Cool in the Summer and Warmer in the Winter

Low E Double Glazing    Low E Double Glazing Christchurch

This clear coating is thin —even thinner than a human hair—so it cannot be seen.  A Low E coating increases thermal performance by reducing ultraviolet and infrared light coming through the glass window, but it doesn't compromise the amount of visible light that is transferred.

Low E coatings reflect radiant heat - either from outside or inside, therefore reducing the heating and cooling costs of your home.

Double Glazing a window can halve the heat loss compared with a single glazed window. You can reduce heat loss further by using Low E Glass or by choosing units which use argon gas instead of air to fill the space between the two panes of glass.


  • Significantly reduces heating loss - compared with Double Glazed Windows without Low E Glass
  • Aligned with the NZ Building Code – improves the minimum energy performance standard of windows
  • Reduces the heating and cooling costs of your home
  • Less condensation – Low E Glass keeps the internal pane of glass warmer therefore reducing the occurrence of condensation
  • Improved comfort – your home is warmer in the winter and cooler in the summer
  • Healthier home - reduced condensation, improved warmth and a drier home
  • Reduces fading of fabrics, carpet, and furniture caused by the sun’s UV light
  • Provides remarkable clarity - the Low E coating does not affect clarity, so you can enjoy the view

Reduce Heat Loss Further with Low E Double Glazing 

The diagram below outlines how heat passing through your glass reduces when you use Double Glazing, Low E Double Glazing and Glazing Argon Gas instead of Air to fill the space between the two panes of glass. 

What is a U-Value?

A U-value measures the rate of heat loss over a surface or material, how much heat passes through your glass. A lower U-value means lower heat transfer and better insulation of your home. 


Low E Glass Types

Stake Glass supplies the following two Saint-Gobian Low E glass types:

PLANITHERM ULTRA N is low-E glass offers advanced thermal insulation properties for the most demanding of glass specifications, where neutrality and excellent performance are paramount.A double glazed window using PLANITHERM ULTRA N low-e glass will give you a U Value of 1.1, when it is combined with a 14mm thermal spacer and argon gas. Click here for further information.

COOL-LITE is used for applications requiring high solar protection and high light transmittance.
A double glazed window using COOL-LITE SKN 176 II low-e glass will give you a U-value of 1.0, when it is combined with a 16mm thermal spacer and argon gas. Click here for further information.

H1 Building Regulation Changes - Windows & Doors

Improvements to the requirements under the H1 Clause of the Building Code, were published by the Ministry of Business, Innovation and Employment (MBIE) in November 2021, and more recently, the transition periods for housing were updated. 

Window and door implementation phasing-in began on the 3 November 2022, with an additional step in the transition period in May 2023. All requirements will be in effect as of 2 November 2023.

Energy efficiency is top of mind, with the update being one of the first steps in the Government’s Building for Climate Change programme.  There are major increases in thermal performance requirements across the building envelope and they have introduced new Climate Zones.


For housing, initially, aluminium frames will require more thermally efficient glass (double glazing with a high-quality Low E pane and an argon gas fill between) to meet the minimum requirements. 

Our Low E glass, Planitherm Ultra N and Cool-Lite both meet compliance with the new requirements.  For more information, click here