Building requirements - The Australian Standard AS 3700-2018 for Masonry Structures Section 4.7.2 says "Weepholes shall be provided to drain moisture from or through masonry construction. Where flashings are incorporated in the masonry, weepholes shall be provided in the masonry course immediately above the flashing, at centres not exceeding 1200 mm."
Bushfire requirements - The Australian Standard for Construction in Bushfire Prone areas (AS3959:2018) stipulates that new buildings in bushfire prone areas require weep hole protection to prevent ember attack. It specifies the requirements for ember screening to meet the various Bushfire Attack Level (BALs).