On 1st of January 2017 Clause H1 Fourth edition Amendment 3 came into force. It calls up the 2009 version of NZS4218 as Acceptable Solution for Clause H1. NZS4218:2004 including the Clause H1 replacement tables remained an Acceptable Solution until 30 May 2017.
From 1 June 2017 only NZS4218:2009 is the Acceptable Solution for Clause H1.
Below is a list of the most important changes in the new Clause H1:
- The Acceptable Solution does explicitly exclude the use of foil insulation. (H1/AS1 1.0.2)
- The maximum permitted area of skylights for using the NZS4218:2009 Schedule Method has been increased from 1.2m² to 1.5m² or 1.5% of the roof area, whichever is the larger. (NZS4218:2009 4.1.1(d))
- Up to 3m² of glazing with an R-value of less than R-0.26 (“decorative glazing and louvers”) is permitted in the NZS4218:2009 Schedule Method. (NZS4218:2009 4.1.1(c))
- The maximum of 50% glazing for using the NZS4218:2009 Calculation