TARGET
The NatHERS thermal performance target for this project was:
24.5 Heating MJ/m2.pa
33.7 Cooling MJ/m2.pa
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Thermal performance is the amount of heating or cooling that makes the interiors of a home comfortable. In other words, it is a measurement of how efficiently your home can retain heat. A building with good thermal performance will need less energy to keep the insides warm and comfortable. (CSIRO)
RESULT
The NatHERS thermal performance result for this project was:
12.4 Heating MJ/m2.pa
15.8 Cooling MJ/m2.pa
28.2 Total MJ/m2.pa
Note: This dwelling was assessed under the NCC2022 energy efficiency regulations.
The Design
In addition to implementing a NatHERs assessment, we aligned our energy efficiency solutions with the client’s vision of a functional modern family home to produce a stunning, intuitive space.
Designer: Hibbards Homes NSW
Location: Junction Hill NSW
NCC Climate Zone: 2
NatHERS Star Rating: 7.6 Stars
A contemporary medium sized modern home, the design provides ample space for busy families to live and function with ease and low maintenance.
Offering 3 generous sized bedrooms containing built in wardrobes as well as a master bedroom with its own ensuite and walk in robe equipped with hanging space and shelving.
The kitchen is open plan, overlooking the combined dining and family living space.
The home contains 3 living areas, the family/dining space, a carpeted media room as well as a kid’s retreat.
This design also includes a privately covered alfresco, perfect for outdoor entertaining.
Climate Considerations
Australia has 8 main climate zones, as defined by the National Construction Code (NCC 2019). Each of these climate zones has different design and construction requirements.
Junction Hill, New South Wales falls into the NCC Climate Zone 2, warm humid summer and mild winter.
Junction Hill is described as having hot summers and cold winters, with the temperature typically varying from 2°C to 32°C. It is rarely below -1°C or above 37°C over the course of the year. (source: weathersparke)
In hotter, more humid climate zones, it is commonly understood that the summer season impacts the cooling load more so than the winter season impacts the heating load. These are important factors that must be considered by all parties during the design process.
The Heating Load is the amount of heat energy that is to be added to a living space to maintain the temperature in an acceptable range.
The Cooling Load is the amount of heat energy that is to be removed from a living space (cooling) to maintain the temperature in an acceptable range.
Thermal Performance Solutions
The external roof colour selection for this particular dwelling is Colorbond Basalt (solar absorptance level of 0.67), whilst the external walls are Driftwood Grey brick, being in the medium solar absorptance range of 0.47.
Total Solar Absorptance is the ratio of the amount of total solar energy absorbed by the object (window). Solar absorption is the portion of total solar energy neither transmitted nor reflected.
The external walls are brick veneer, with a metal roof sheeting.
The windows are predominantly sliding with the addition of one fixed window in the Garage.
The design of this home is to accommodate a busy, young family therefore, the following thermal performance solutions were selected as a result of the NatHERS Assessment.
External Walls:
- Antiglare + R2.0 Glass Fibre Batts
Internal Walls:
- R2.0 High Density Glass Fibre Batts to the internal walls joining to the Garage only.
External Floors:
- No insulation
External Roof / Ceiling:
- R1.30 Anticon Blanket / R3.5 Glass Fibre Insulation Batts
Windows:
- Single Clear Glazing with Aluminium Frames
NatHERS 7.6 Stars
Achieving 7.6 Stars: The above performance solutions achieved a NatHERS Star rating of 6.9 stars, just falling short of the NCC2022 minimum requirement of 7 stars. A decision was therefore made to include 5 ceiling fans as follows:
Ceiling Fans: 1200mm to all four bedrooms and one living room.
The NatHERS Star rating after adding the above-mentioned ceiling fans achieved a final rating of 7.6 stars.
