The Tax Office recently released two GST ‘advices’ on whether certain additions to houses constitute ‘substantial renovations’ making the premises ‘new residential premises’ for the purposes of the GST law. In these advices, the Tax Office explains its view that the addition of a second storey to a single storey house or the addition of four rooms to a six-room house does not constitute ‘substantial renovations’. Accordingly, the sale of the premises will not be taxable supplies of new residential premises. Instead, they will be input taxed supplies. As a result, taxpayers will be able to apply the principles expressed in the Tax Office’s ruling to determine the correct GST treatment of supplies of residential premises.