by caleb » Tue Jul 24, 2012 12:33 pm
Gordon, the house energy rating scheme is only concerned with the thermal performance of the building (i.e. roof, walls, floors, windows, doors etc.). There is also a requirement for artificial lighting to be below 5W/m2 which was introduced last year.
As for heating and cooling systems, hot water systems, appliances, solar PV etc. these are not considered in the assessment. The reasoning behind this is that these items generally have a shorter lifespan than the building, and new owners may reasonably change or replace them.
Perhaps your friend had a different kind of assessment performed, like the free Sustainability Assessment which the government was promoting a couple of years ago (where someone would come into an existing home and make recommendations). At the time there was much uproar about the accuracy of this particular assessment program, and also some issues regarding the training and expertise of the assessors.