Sizing steel lintels for brick veneer
Steel lintel sizes used to be given in NZS 3604:1999 Timber-framed buildings, but all cladding information was removed from the 2011 standard. The requirements for brick veneer construction are now contained in E2/AS1 (the 2011 version that incorporates Amendment 5). Steel lintel sizes are given in Table 18E on page 116.
Summarised from BRANZ Guideline(external link), November 2013.