The NCC 2022 energy efficiency provisions introduce 7-Star NatHERS ratings for new residential buildings, driving improved thermal performance, reduced energy use, and enhanced occupant comfort. Architects and builders must adapt their designs and construction methods to comply with these changes while balancing cost and design flexibility.

Key Changes & What to Expect:

Higher Minimum Energy Efficiency Standards
  • The minimum thermal performance standard for new homes has increased from 6 stars to 7 stars under the Nationwide House Energy Rating Scheme (NatHERS).
  • This applies to Class 1 dwellings (houses and townhouses) and Class 2 apartments.
  • A new Whole-of-Home energy rating must be met, considering the energy usage of fixed appliances (heating, cooling, hot water, lighting, etc.).
Key Design Considerations 
  • Passive design principles are now critical to meeting the new 7-star standard:
    • Improved orientation and zoning to maximize natural heating and cooling.
    • Enhanced insulation and glazing to reduce heat loss and gain.
    • Tighter building envelope to minimize air leakage.
    • Shading strategies (eaves, pergolas, landscaping) to reduce overheating in summer.
  • Thermal bridging and junction detailing must be carefully managed to prevent heat transfer.
  • Window-to-wall ratios and glazing selection will significantly impact compliance.
What Builders Need to Watch For
  • More stringent insulation requirements:
    • Walls, floors, and roofs must have higher R-values to improve heat retention.
    • Installation quality is crucial – gaps and compression in insulation will compromise performance.
  • Air-tightness is now a key focus:
    • Expect increased attention on sealing around doors, windows, and penetrations.
    • Blower door testing, while not mandatory, is being strongly encouraged to ensure compliance.
  • Ventilation balance:
    • While homes must be airtight, they also need adequate fresh air through ventilation systems or mechanical solutions like heat recovery ventilation (HRV).
Whole-of-Home Energy Budget & Renewables
  • New homes must comply with an overall energy budget that considers heating, cooling, hot water, lighting, and appliances.
  • Solar PV systems, battery storage, and energy-efficient appliances will become more common to offset energy consumption.
  • Gas appliances are less favoured, with an industry push toward all-electric homes.
Compliance & Certification
  • Energy rating assessments will be stricter, requiring detailed thermal modelling and energy assessments.
  • Builders must provide evidence of compliance, including:
    • NatHERS certificates for thermal performance.
    • Whole-of-home energy calculations.
    • Documentation on insulation and glazing performance.
Why It Matters:
  • Non-compliance could lead to costly redesigns, delays, and rework.
  • Higher-rated homes are more comfortable, energy-efficient, and cheaper to run.
  • Early planning with energy consultants is crucial to achieving compliance without compromising design.

 

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