NatHERS enables the design of a home to be assessed by skilled professionals using sophisticated computer modeling programmes to improve the quality of design and achieve building approvals in Australia. NatHERS sets national standards for professionals offering assessment services as well as the software they use. Zero stars means the building shell does practically nothing to reduce the discomfort of hot or cold weather. A 5 star rating indicates good, but not outstanding, thermal performance. Occupants of a 10 star home are unlikely to need any artificial cooling or heating.