Local Practice Snapshot - BCA 2010 6-Star Public Comment Draft
Published: 22 July 2009 / Amendment 1 / BCA 2010
In July 2009 the Building Commission (formerly DHW) engaged As-Built Learning Exchange to undertake a 6-Star Local Practice Snapshot to assess the likely impact of the draft BCA2010 Energy Efficiency provisions (commonly referred to as 6-Star Housing).
PROJECT BRIEF
Given the short timeline from the release of the draft provisions to the close of the Public Comments period, the project brief was restricted to analysis of houses in the first and second homebuyer segment of the Perth project housing market (see Project Flowchart)..
This also limits the scope of reporting to Climate Zone 5. It is likely that similar research undertaken for houses Climate Zones 1 and 3 (northwest) and Climate Zones 4 and 6 (central and southern) would show a far greater impact than that found for Climate Zone 5.
METHODOLOGY
On 9 July, Design and Drafting Managers from Perth based project builders were invited to a 6-Star Local Practice Snapshot Briefing Session. This session outlined the BCA public comment process, provided a brief overview of the proposed amendments to the BCA 2009 Energy Efficiency provisions, and invited Builders in the first and second homebuyer market segment to provide house assessment data for use in the analysis process (see Briefing Session Notes Flowchart).
House Sample
Builders responded promptly to the invitation to participate and provided 45 sample houses.
These houses were sorted into single and double storey house clusters (single storey: 90–130m2, 130–160m2, 160–210m2, 210–250m2; double storey: 210-280m2 – overall external walls). Within each cluster, indicative house types were then identified (terrace house, narrow lot, side facing living etc).
From these indicative house types, 10 typical examples houses where selected for detailed assessment (8 single storey, 2 double storey).
Assessment and Analysis
Builders provided BCA 2009 Glazing Calculator assessment data for the house in one orientation. External Glazing data was then generated for the remaining seven orientations to establish the BCA 2009 (5-Star) baseline data for each house. Each of the 10 houses was then assessed in each orientation using the draft BCA 2010 beta 0.2 Glazing Calculator. BCA 2009 and BCA 2010 results were then compared and, for each home, modelling was undertaken to determine the options that could be used to achieve BCA 2010 External Glazing compliance.
Each of the homes was then reviewed to determine what was required to achieve compliance with other parts of the draft BCA2010 Deemed-to-Satisfy (DTS) provisions.
Two of the single storey houses were then selected for simulation-based assessment (using House Rating Software – BERS and AccuRate) to provide an indication of likely differences between simulation and DTS assessment outcomes (see Simulation Assessment Results following the able below).
ASSESSMENT NOTES
Click the link below to download the full report and detailed assessment notes.
Building Professional Registration or Login Required
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