Skip to main content

BU579 WEERS - Window Energy Efficiency Rating System


Product Description

The Window Energy Efficiency Rating System (WEERS) is a 6-star rating system for assessing the thermal performance of new residential windows. It was developed by BRANZ in conjunction with the Window Association of New Zealand (WANZ). WEERS combines the thermal performance of the frame and glazing, together with the size of the window, to calculate an individual thermal performance rating for each window.

This bulletin replaces Bulleting 474 WERS – Window Efficiency Rating System.

The bulletin covers:

  • how does WEERS work
  • window specification and manufacture
  • comparing windows
  • what is not covered in WEERS
  • window thermal performance rating calculation
  • calculating a WEERS rating.
Product Information
Publication date 2 December 2014
Product type Bulletin
Availability Available
Product code BU579