Home Style Green Matthew Cutler-Welsh

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

Scott Fisher is the CEO of Offsite NZ. I caught up with him to discuss the history, current practice and future opportunities of offsite manufacturing in the building industry in Aotearoa. 
https://www.offsitenz.com/

While researching a presentation to open the NZGBC 2024 Housing Summit, I looked into the climate initiatives of Europe and the US. 
In Europe, over €83b has been recently been committed by the European Parliament as part of the Energy Performance of Buildings Directive. The ultimate goal is that the building sector will be climate neutral by 2050. Importantly, there are interim goals for 2030 and 2040, which encompass both new buildings and retrofitting existing buildings. 
https://energy.ec.europa.eu/topics/energy-efficiency/energy-efficient-buildings/energy-performance-buildings-directive_en
Over in the US, there is the Inflation Reduction Act which will see a staggering $783b invested into energy security and climate change initiatives. 
https://www.whitehouse.gov/cleanenergy/inflation-reduction-act-guidebook/
Back here in Aotearoa, aside from recently updating H1 Energy Efficiency in our building code, MBIE has laid out a programme called Building for Climate Change. 
https://www.building.govt.nz/getting-started/building-for-climate-change
The implementation plan for BfCC has reporting requirements suggested for 2025. 

This week I attended a BRANZ seminar titled 'Building for our changing climate'. Tāmaki Makaurau Auckland was the last stop on the BRANZ seminar tour of the country and it's encouraging to think that rooms of designers, builders, product suppliers, building officials and others, were interested enough in this topic to take four hours out of their week. 
A key takeaway is that we're not prepared. We're already handicapped by having insufficient standards in our building code to deal with our current climate. With the forecast being 'warmer and wetter', the situation is set to get worse.
https://homestylegreen.com/?p=5936

Steve Penny is the founder and director at Honoris, a building services consultancy in Christchurch, New Zealand. He is also the host of his own podcast, A Penny for Your Thoughts.

Many people might be surprised to know that the New Zealand Building Code does not require any consideration of overheating in homes. The energy efficiency requirements in our code are based only on the ability of buildings to keep warm without excessive heat loss. There is nothing to prevent homes from being designed with large areas of unshaded north or west-facing glass.

Siân Taylor is an Architect and Passive House Designer based in Queenstown. She has experience creating homes that are designed to perform well all year round, in some of the most challenging and spectacular locations.

Follow Siân on Instagram and check out Team Green Architect's latest work at https://www.teamgreenarchitects.co.nz/.