Build Aotearoa 13: Homestar vs Building Code

The New Zealand Building Code does not guarantee performance in all areas that many homeowners might expect. Fortunately, Homestar is available to close the performance gaps.

Homestar Headline Benefits
•    Fresh air
•    Dry
•    Comfort
•    Carbon  

Homestar Design Checklist
This is a summary of the basic requirements over and above basic building code compliance for achieving 6 Homestar v5. Inclusion of everything here does not guarantee compliance but is a starting point for what should be considered.

• Homestar Designer: This can be someone within the project team or an external consultant. Engage them in the process as early as possible.
• Energy model: Homestar v5 uses predicted performance criteria rather than a schedule of allowable insulation levels. The performance criteria include estimated energy consumption, winter and summer internal temperature and likely carbon emissions and these can be calculated using the Energy and Carbon Calculator for Homes (ECCHO). Energy modelling used to be a highly specialised process and expensive process. ECCHO makes energy modelling accessible to Homestar Designers
• Continuous mechanical ventilation: Internal moisture is a significant problem for New Zealand homes and there is adequate evidence that the building code requirements of openable windows is not reliable for providing enough fresh air and removing dampness. There are simple solutions available for 6 Homestar that are nearly silent, cost very little to run and will provide much more reliable benefits to homeowners.
• Thermally broken windows: Pay attention to the window frames, not just the glass.
  Slab edge insulation OR above slab insulation: Junctions such as the connection between walls and floors are risk areas for condensation. Some additional insulation detail can help prevent this and can be easily incorporated when considered early.
• Water efficient fittings: These are commonly available. Select the best WELS rated products. 

For more, visit https://nzgbc.org.nz/introduction-to-homestar