Double Glazing Manufacturers

IGUMA (Insulated Glass Unit Manufacturers Association) is a group of Glass Processors who have agreed to an (independently verified) testing regime.  Your IGUMA Member supplier can provide you with a copy of the current compliance certificate for the product you are purchasing.

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.

Identification of Insulating Glass Units

The New Zealand Building Code Clause B2 (amendment 9, January 2017) modifies NZS 4223 Part 2 as follows:

5.3 Marking

Insulating glass units shall be permanently and clearly marked. As a minimum, marking shall include the following:

  1. a) The name or registered trademark of the manufacturer or supplier;
  2. b) The date of manufacture (use the year as the minimum), and
  3. c) Complies with NZS 4223.2:2016.

Marking shall be visible after the IGU has been installed, and must be legible and durable for the life of the unit.


  • Etching and permanent laser marking are acceptable means for marking insulating glass units.  Externally affixed adhesive labels are not acceptable.
  • Additional Marking may be used by the manufacturer.