How Low E glass works

Double-glazing is made from two pieces of glass sealed together with an air space or gas in between. Triple glazing takes this one step further and adds an extra piece of glass and another air or gas space.

Metro Double and Triple Glazing units are Insulating Glass Units manufactured and sealed in the manufacturing process. They consist of two panes of glass separated around the edges by a spacer and sealed at the perimeter in factory-controlled conditions. The spacer contains a desiccant-drying agent, which absorbs moisture vapour in the cavity. 

New Zealand building standards require new homes to be fitted with higher performance than single glazing.  Recognising that single-glazed windows transfer cold very easily through the glass, and cause condensation to form on the inside of the windows.  Double and Triple glazing work to separate this outside piece of glass from the inside to reduce the amount of heat that flows through a single piece of glass.  The current national performance standard has one performance level, across the three climate zones.  In the MBIE proposals its seems likely there will be a move to six with higher thermal performance requirements for windows.

Whatever you are trying to achieve whether it’s keeping your home warm or cool, trying to reduce noise, UV or sun or even increase security? Metro Performance Glass can help select the right Low E double glazing that delivers the right level of performance of what you are looking to achieve. So you can enjoy a more comfortable home.


As a member of the Window and Glass Association Metro, are also part of the IGUMA sub group.

IGUMA (Insulated Glass Unit Manufacturers Association) is a group of Glass Processors who have agreed to an (independently verified) testing regime.

NZS4223.2:2016 requires IGU to be tested and demonstrate compliance.  IGUMA members who comply with IGUMA-BS EN1279 testing also comply with the requirements of Section 5 of NZS 4223.2:2016.