Architecturally inspired systems for superior style and performance

Alert: Using incorrect performance values

05 November 2014

incorrect-performance-values

AlertRecently, the Australian Window Association (AWA) has alerted the industry that non-members were advising energy raters to use glass only values (Ug) rather than the whole window value (Uw).

Energy assessors using free on line calculators were being encouraged to use glass only U-Value (U GLASS) and Solar Heat Gain Coefficient (SHGC GLASS) performance results in the absence of immediately available whole window custom ratings to carry out building performance ratings.

Under the National Construction Code (NCC) within the Building Code of Australia (BCA), energy efficiency provisions for Volume One, Section J2.4 Glazing and Volume Two, Section 3.12.2.1 External Glazing, states that external glazing performance data must be determined in accordance with the guidelines of the Australian Fenestration Rating Council (AFRC).

By not using the total window system values to Australian approved procedures and environmental conditions, it can result in significant under performance or over performance of the building envelope, especially in buildings with large glazed areas. The stated performance of the building will not meet the energy efficiency provisions of the BCA.

Architectural Window Systems (AWS) has tested our entire range of window and door systems, ensuring energy ratings for all of our frames are easily available. These can be found on the Window Energy Rating Scheme website at www.wers.net.

To read the full article on the Incorrect Use of Glass Only Values for Glazing Energy Performance Ratings, please see http://www.awa.org.au/resources/incorrect-use-of-glass-only-values-for-glazing-energy-performance-ratings.

Subscribe for specification insights, tools and resources