Case Study

Nelson Bay Duplex



The NatHERS thermal performance target for this project was:

58.3 Heating MJ/
33.0 Cooling MJ/

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)


41.0 Heating MJ/
28.5 Cooling MJ/

69.5 Total MJ/


41.5 Heating MJ/
28.4 Cooling MJ/

69.9 Total MJ/

Thermal Solutions

We collaborated with Torren Bell Building Design to develop a strategy to ensure this stunning multi-dwelling project achieves compliance with New South Wales construction and energy efficiency requirements whilst aligning with the owner’s overall vision.

Designer: Torren Bell Building Design

Location: Nelson Bay NSW 

NCC Climate Zone: 5 – Warm Temperate 

NatHERS Star Rating: 6 Stars 

BASIX: Deemed to Satisfy Compliance  

Solar: 3Kw per dwelling  

Rainwater Tanks: 3000L per dwelling

beach chairs

The Design

Boasting a contemporary design and luxurious finishes that exude elegance and sophistication, this modern three storey duplex is located on one of Nelson Bay’s most sort after streets overlooking Dutchman’s Beach.  

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.

Nelson Bay’s climate is classified as warm and temperate, being a city that receives significant rainfall, even in the driest months.

  • The average temperature through the year in Nelson Bay is 18.3 °C.
  • The maximum average daily temperature during the summer months is 26 °C.
  • The minimum average daily temperature during the winter months is 9 °C.
  • The rainfall is around 984 mm | 38.7 inch per year.

Thermal Performance Solutions

A combination of both dark and light colours has been selected for the external walls whilst the roof is predominately light. As lighter colours reflect the sun and darker colours retain more heat the chosen colour scheme is a perfect combination for a waterfront home in Nelson Bay.  

Opting for concrete slab on ground (which acts as additional thermal mass) topped with polished timber throughout each dwelling lessens the demand for heating and cooling energy all year round. 

The inclusion of ceiling fans in all bedrooms, kitchen and living areas also lessens the need for additional cooling via mechanical devices such as air conditioning. 

External Walls:   

  • Brick veneer cement rendered stud wall with reflective sarking and R2.00 fibreglass insulation batts. 
  • Fibre cement cladding with R2.00 fibreglass insulation batts 
  • Concrete block veneer with R2.00 fibreglass insulation batts 
  • RMAX EPS cladding panels with R2.00 fibreglass insulation batts 
  • Internal walls – plasterboard with 90mm non-reflective air gap and R2.00 fibreglass insulation batts 



  • Concrete slab – no insulation 
  • Suspended timber floor – with R2.00 fibreglass insulation batts 
  • Timber floors. 


External Roof /  Ceiling:   

  • R1.30 anticon blanket +40mm reflective air / R4.0 fibreglass insulation batts 

Ceiling Fans:  

  • 1200mm in all bedrooms and 1400mm in living area and kitchen. 


  • Single clear and double-glazed windows with aluminium frames. 


Household Features