Unlock the secrets of how a NatHERS Existing Homes assessment is meticulously conducted from start to finish.
NatHERS Existing Homes assessments can only be conducted by accredited NatHERS assessors. These professionals have undergone rigorous training and certification to ensure they are well-versed in the technical standards and methodologies required for accurate assessments. Accreditation is managed by organisations such as the Australian Building Sustainability Association (ABSA) and the Building Designers Association of Victoria (BDAV).
Assessors must adhere to strict guidelines and maintain their accreditation through continuous professional development. This ensures that they stay up-to-date with the latest advancements in building science and energy efficiency standards. Homeowners looking to have their existing homes assessed should always verify the credentials of their chosen assessor to ensure compliance with NatHERS requirements.
The data collection phase is crucial as it forms the foundation of the NatHERS assessment. Assessors gather a comprehensive set of data related to the building's physical characteristics and its thermal performance. Key information includes the home's floor plans, elevations, and sections, which provide detailed insights into the building's layout and design.
Additional data collected includes the types of construction materials used for walls, roofs, and floors, as well as information about insulation, glazing, and shading devices. The orientation of the building and its geographical location are also noted, as these factors significantly impact thermal performance. Ventilation details and the presence of any renewable energy systems are also recorded to provide a holistic view of the home's energy profile.
Several specialised tools and software are employed during a NatHERS Existing Homes assessment to ensure accuracy and consistency. Accredited assessors use NatHERS-approved software such as AccuRate, BERS Pro, and FirstRate5. These tools are designed to simulate the thermal performance of residential buildings based on the collected data.
The software models the building's energy usage and predicts how it will perform under various climatic conditions. It takes into account factors such as solar heat gain, heat loss through building fabric, and the efficiency of heating and cooling systems. The use of these sophisticated tools allows assessors to provide a detailed and reliable energy efficiency rating for the home.
The assessment process begins with an initial consultation where the assessor explains the scope and objectives of the NatHERS assessment to the homeowner. This is followed by a thorough site visit where the assessor collects all necessary data, including measurements and observations of the building's features and systems.
After the site visit, the assessor inputs the collected data into the NatHERS-approved software. The software runs simulations to analyse the thermal performance of the home. The assessor reviews the results, ensuring that all data has been accurately captured and that the simulations reflect the actual conditions of the home. The final step involves compiling a comprehensive report that details the home's energy performance and provides the NatHERS star rating.
The star rating is a key outcome of the NatHERS assessment, representing the home's energy efficiency on a scale from 0 to 10 stars. The rating is calculated based on the amount of energy required to heat and cool the home to maintain comfortable indoor temperatures. Homes that require less energy to achieve this are awarded higher star ratings.
The software calculates the star rating by simulating the home's thermal performance over a typical year, taking into account local climate data. Factors such as insulation levels, window performance, and building orientation play significant roles in determining the final rating. A higher star rating indicates better thermal performance and lower energy consumption, providing homeowners with a clear indication of their home's energy efficiency.