Under the National Construction Code (NCC), new residential builds (housing, residential apartments, multi – dwelling development) as well as build extensions are required to achieve a minimum Star Rating with respect to the building envelopes ability to meet minimum heating and cooling loads (Thermal Comfort). Different climate zones across Australia require different approaches to meeting the minimum Star Rating.
The role of an ABSA Accredited Assessor is to use the appropriate Nationwide House Energy Rating Scheme (NatHERS) – approved rating software to determine the Star Rating. In carrying that process through the Assessor will provide guidance regarding building materials, window and other products as well as other specifications.
An Accredited Assessor will use one of three Software’s (BERSPro, FirstRate5 and Accurate) to enter data to develop a simulation model of the residence to determine expected indoor temperatures based on data specific to that dwelling.
The following elements are considered:
The software will then model how much cooling or heating occupants may need to stay comfortable during a typical year. It does this by firstly simulating how the local climate heats and cools the house every hour of every day of the year.
This includes information on design and construction, climate and common patterns of household use. The software tools do not consider electrical appliances in the dwelling, apart from the air flow impacts from ceiling fans.
Once internal temperatures fall outside a comfortable range, the software models the need for heating and cooling on the assumption that the occupants of the house will firstly open and close windows and any blinds or awnings to restore comfortable internal temperatures (when it makes sense to do so) before using any heating or cooling system. The total estimated annual heating and cooling requirements are then converted to a star rating out of 10 stars. Further information on the process