The scope for this work is to design, develop and document an Excel-based calculator for residential energy efficiency, which covers the current (NCC 2022) Deemed-to-Satisfy (DTS) elemental provisions in Section 13 Energy Efficiency of the ABCB Housing Provisions Standard. The DTS calculator will be applicable to all Class 1 buildings i.e., both 1a and 1b. The calculator will incorporate the following existing ABCB residential calculators; external glazing, Whole-of-Home (WOH) energy usage and artificial lighting. The front end of the existing calculators can be modified to suit this new all-encompassing calculator, however no other changes will be required to the existing ABCB calculators.

The DTS calculator will be designed to provide industry with a simple and clear tool to assist in following the DTS elemental pathway for NCC 2022. The calculator will be easy to access, easy to use with inbuilt instruction and explanatory detail. The calculator will also provide a summary level report that can be used by the key stakeholders to include in the building design documentation for relevant approvals and certifications by a building surveyor.

The DTS calculator, for simplicity and access within the stakeholder group, will be developed in Microsoft Excel and must also operate effectively on a range of Excel versions going back at least 8 years. Ongoing maintenance of the calculator is not included within the scope of this work.

The focus of the calculator is only on the Energy Efficiency provisions in Section 13 of the ABCB Housing Provision Standards. The following sub-categories of Section 13 will require inclusion in the calculator:

• Building fabric
• External glazing (existing glazing calculator)
• Building sealing
• Ceiling fans
• Whole-of-Home (WOH) energy usage (existing WOH calculator), and
• Services (including the artificial lighting calculator)

The timeline for this work is that the user acceptance testing will be completed, and a beta version of the tool will be ready for board approval by 01 March 2024.