Explore every episode of the podcast Home Style Green

We got the band back together!

I caught up with Sharon Robinson and Glenn Harley to discuss some topical housing issues, including;

- The legacy of Minister Chris Penk

- "The right houses, in the right place", according to Minister Chris Bishop

- H1 and timber fraction in walls Links:

- Sharon's new book, "Babe! Let's build a house", https://www.smartlivingspaces.nz/book

- Community Housing https://www.rnz.co.nz/news/community/1055757/growing-homelessness-linked-to-tighter-emergency-housing-rules-community-leader-says

- Housing Dashboard https://www.hud.govt.nz/stats-and-insights/the-government-housing-dashboard/social-housing

- I'm loving watching videos from BAS Renovations in Michigan. https://www.facebook.com/B.A.S.Renovations.734

- Comfortech H1 Hub counter batten wall solution  https://www.comfortech.co.nz/h1-hub/wall-insulation-solutions/

- OSM 3604 https://www.osm3604.nz/

- Upcoming energy modelling training 

https://nzgbc.org.nz/homestar-training

 - Check out more interviews on the Passive House Podcast

https://passivehouseaccelerator.com/podcast 

Passive House Institute New Zealand has just wrapped up its two-day conference in Auckland, with the theme of 'Passive House is a team sport'. Among the speakers was Tom Webster, registered Architect and host of Grand Designs New Zealand. I caught up with Tom and current PHINZ Chair Joe Lyth at the end of day 1.

Welcome to the first episode of Build Aotearoa for 2026.  

Coming up this year,  the NZGBC will be celebrating 20 years of advocating for better buildings in New Zealand. The update of the update of H1 is bedding in, but many builders are turning their attention to roof condensation and overheating. And the market seems to be in a prolonged period of 'cautious optimism'. 

In this episode, I continue my coverage of the THRIVE 25 Conference with a series of interviews from the trade show floor. I spoke with leading suppliers whose products and innovations are helping shape the future of Passive House construction in Australasia. From high-performance windows to advanced ventilation systems, each guest shares their unique contribution to better building.
https://www.passivhausassociation.com.au/

1. Scott Hogan – DEHUM
Scott discusses DEHUM's advanced humidity control systems and their role in maintaining optimal indoor environments for Passive House projects.
https://dehum.com.au

2. Mark Ristevski – XTour3D
Mark introduces XTour3D's cutting-edge 3D scanning solutions for construction, bringing 'digital twin' technology to the residential market.
https://xtour.com.au/

3. Mike Ward – Australian Glass Group
Mike shares insights into high-performance glazing solutions and the importance of energy-efficient glass in Passive House design.
https://agg.com.au/

4. Mark Heyman – Rotho Blaas
Mark highlights Rotho Blaas' construction systems, including airtightness and waterproofing.
https://www.rothoblaas.com/

5. Ashley Griffs – BINQ Windows
Ashley showcases BINQ's locally manufactured timber, alu-clad, and uPVC windows that meet Passive House standards for thermal performance and security.
https://www.binq.com.au/

6. Adam Socha – Kinzel Industries & Aluplast
Adam talks about Kinzel's partnership with Aluplast, delivering innovative uPVC window systems with exceptional energy efficiency and design flexibility.
https://www.aluplast.net/eng-int/company/

7. James Hazelwood – Hygge Windows
James presents Hygge Windows' approach to combining aesthetics and performance in window design, tailored for sustainable living.
https://hyggewindows.com.au/

8. Harley Truong – Logikhaus
Harley explains Logikhaus' commitment to Passive House certified windows and doors, and their role in delivering high-performance building envelopes. Plus a summary of Harley's conference presentation, proposing how we might report and communicate better about Passive House benefits.
https://www.logikhaus.com.au/

Once again, a big thank you to Andy Marlow and Taline Edwards at Envirotecture for making this possible.

I chatted with the wide range of exhibitors at the 2025 Australian Passivhaus Conference, THRIVE 25 in Melbourne. This year saw a growing contingent of panel suppliers along with a variety of window manufacturers, membrane suppliers and more.

Special thanks to Environtecture and the Australian Passivhaus Association for supporting the Passive House Accelerator to be there and bring you these highlights. 

Peter Sullivan, Smart SIPs
Peter introduces us to his structural insulated panel system designed to simplify construction while delivering high performance for Passive House and other energy-efficient builds.

Annettee Braagaard, Nordic Blinds
Annettee shares how intelligent Danish blind systems support shading and comfort in Passive House projects across Australia.

Ben Mitchell, SIP Solid and Solcraft

Ben explains how their Solcraft panels can help deliver stronger, warmer homes in the Australian market.

Rohan Madathanapalli, Bondor Metecno
As Principal Sponsor of THRIVE 25, Rohan outlines Bondor's role in advanced panel technology and how one product can serve multiple functions, speeding up products and helping to reduce overall cost.

Klaus Herrmann, Alpine Passive House
Klaus highlights the benefits of Australian-made prefabricated panels design with European experience.

Thomas Paarhammer, Paarhammer Windows & Doors
Thomas shares insights from over 30 years of crafting high-quality windows and doors tailored for Australian conditions and Passive House requirements.

Villy Yordanov, Pro Clima Australia
Villy explains some of the new products available from long-time Passive House support, pro clima.

Rachael Sparnon-Freeman, Pacific Ventilation
Rachael discusses mechanical ventilation solutions, indoor air quality, and how Pacific Ventilation can support both commercial and residential projects.

Joel Seagren, Fantech
Joel speaks about fan technologies and their application in Passive House ventilation systems and energy recovery solutions.

Michael Drage, Reimagined Habitat, Net Zero Plus, Efficient Habitat
Michael talks about communicating passive house in the language of clients, drawing on his experience from the financial sector.

The government is seeking consultation on insulation standards. Again.

Jason Quinn has waded through the details and provided a handy summary. Check it out, and get your submission in by 28 February 2025.

The government has released New Zealand's second emission reduction plan and it does mention building and construction. 

Elrond Burrell shared his thoughts. 

View the ERP 2 at https://environment.govt.nz/publications/second-emissions-reduction-plan-at-a-glance/

Follow Elrond on LinkedIn and read his review of ERP at https://www.linkedin.com/pulse/erp2-building-construction-what-impact-have-elrond-burrell-6ztjc/

I'm now on Bluesky @kakarikicastle.bsky.social 

I'm joined again by Sharon Robinson and Glenn Harley for a chat about the possibility of builder self-certification and MBIE's updated weather files. 

Wao Summit 2024 is happening next week, 29th October - 2nd November.
Speakers include John Bell, Monique Kelly, Dr. Jim Salinger, Alec Tang, Jane Lloyd, Dr. Greg Bodeker, Sam Gibson, Paul Spoonley and more!
Tickets and information https://www.wao.co.nz/summit2024

I caught up with Glenn Harley and Joseph Lyth to talk about the recent Passive House conference in Wellington, and other building issues in Aotearoa. 

https://www.resilienz.co.nz/

Notes from RMBA's Constructive Industry Forum. 

Wao is a collective dedicated to a regenerative future.

I caught up with co-founder Monique Kelly to discuss why she does what she does, and their upcoming Summit. 

For more information check out https://www.wao.co.nz/summit2024 

99 Waiwai Drive, Milldale north of Auckland looks like a regular new house in a regular new subdivision, but around 30 people visited the site mid-build to see why it's different. This showhome will be one of the Platinum Homes high-performance range. It's a SIP (structural insulation panel) construction and achieved a near Passive House level of airtightness. 

I caught up with Sam Watt, the General Manager of Platinum Homes, Rodney. 

https://www.platinumhomes.co.nz/our-homes/house-and-land-packages/99-waiwai-drive-milldale/

https://formance.co.nz/

Kirsty Merriman is a property developer who is conscious about the type of homes she delivers. She's interested in sharing her knowledge about profitable and responsible project management. https://kirstymerriman.com/

In this episode of Build Aotearoa, I explore the concept of building circularity and its impact on the construction industry. Learn about deconstruction vs. demolition and reflect on the reduce-reuse-recycle hierarchy. I also discuss the role of polystyrene pods and alternative fillers in concrete slabs. 

Be sure to check out recent episodes of the Passive House Podcast from the Passive House Accelerator for more on building cicularity.

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/.

Stärke has been in the window industry in New Zealand since the 80s. They were at the forefront of supplying aluminium frames to the building industry but have recently made some big changes. With a focus on building performance, Benjy Simmons describes the new direction of Stärke as a 'once-in-fifty-year' change. While the company has a long legacy, they've experienced rapid change over the last few years. 

Benjy credits some of the openness to change to him being from outside the industry. He's come in with a different perspective. "We're beginning to see ourselves as a building performance company not just a window and door company", says Benjy. 

Check out the full range of Stärke products along with their education pages and other resources.

More is not always better, especially regarding the amount of timber in the frame of a house. The more timber there is, the less space there is for insulation. The way this is measured is called timber fraction.

Most homes in Aotearoa are designed using the assumption that timber will make up around 14% - 18% of the area in a wall. A 2020 BRANZ research study found that in reality, the average timber fraction is closer to 40%. This means there is considerably less space available for insulation.

Unfortunately, this is not always picked up during the consenting or pre-lining inspection process. H1 Energy Efficiency calculations are checked at the design stage, usually using the much lower default timber fraction assumption. The result of all this is that many consumers are effectively getting less insulation than they're paying for, and much more thermal bridging. 

PlaceMakers has recently launched a new service providing a detailed report of the actual timber content for any wall frame and roof truss they supply. This accurate figure can then be used to provide true H1 calculations. Alternatively, a designer might choose to adapt their plan to reduce the thermal bridging and increase the amount of insulation.

National Technical Resource Manager, Pete Hammond explains how Framology works. We also discuss the option of using external insulating products like RigidRAP-XT from IBS to eliminate thermal bridges.

Denise Martin has been involved with many of Aotearoa's Passive House projects. As one of the most experienced blower door testers in the country, she's been involved with verifying a range of residential and commercial buildings both in New Zealand and Australia.

I caught up with Denise to chat about how she got into building science in the first place and some of the challenges and opportunities facing the building sector in New Zealand. We also discuss the building code, energy modelling, thermal performance and air tightness.

If you don't already, I highly recommend following Denise on Instagram, TikTok and LinkedIn.

I found it confronting listening to Tova O'Brien's guest this past week as she described the experiences of staying in motel emergency accommodation with a young daughter. From my relative privilege (of choosing the right parents and having things turn out ok for me so far), I find it hard to imagine being in this situation. But it's the reality for nearly 6,500 people across Aotearoa, half of whom are children. 

This is an emergency, and the problem is complex. The solution will require more than simply building more houses because the underlying issues are more complex than that.

Related to this is a proposal from the Ministry of Business Innovation and Employment (MBIE) to review the building consent process in New Zealand. This is something I'd like to look at in more detail because we must get the balance right.

In 2023, MBIE sought public submissions in response to an options paper on a review of the building consent system. This week MBIE published a summary of the 270 submissions received.

At the other end of the spectrum, I caught up with Jonathan Holmes about living in a Certified Passive House Premium home and working on assessing the embodied carbon in our buildings. 

Other links for this week's podcast episode:

• Jonathan Holmes on LinkedIn
• Holmes House, Sustainable Engineering
• Hawea Flat, Home Style Green

Be sure to register for Reimagine Buildings '24

Last week, February 22nd rolled around. This was a significant date in the Cutler-Welsh household thirteen years ago when our house was located close to the Avon River in Christchurch. While it was a life-changing day for us, life has gone on. We ultimately lost our recently renovated home in Richmond as a result of the Canterbury Earthquakes, but many lost so much more. 

What would a moratorium on consenting new buildings in known floodplains, tsunami or fire risk areas, look like? How would the resulting plummet in land values impact the economy and further inflate the cost of housing?

But if not now, when? The risks are likely to get higher and ultimately we have to ask ourselves if we're prepared to keep making our stop-banks higher or retreat to higher, less shaky ground.

There are fundamental gaps in what the New Zealand Building Code covers and how well it covers the aspects that are included. These reasons should be enough to justify using standards like Passive House or Homestar to go above and beyond the building code.

In this series, I'll be looking at reasons why it's better to ask about the value and risk minisation resulting from higher performance standards rather than focussing only on perceived upfront cost. 

As I draft this episode, there's a chorus of cicadas outside my window. The sun is shining and there's a faint breath of a breeze. It seems calm where I live, here in a relatively leafy part of Tāmaki Makaurau. 

But all is not calm everywhere in Aotearoa today, Waitangi Day 2024.

There are not many new ideas in the building industry. The basic concepts have been around for a while. 'High-performance' products and design details that might be described as 'innovative' here in New Zealand are likely to be standard practice somewhere else.

With building his experience in Europe and Scandanavia Richard Eden is well placed to help New Zealand builders do things better. He can often be found teaching builders around the country how to do a good quality install of good quality windows.

Brad Wills is Director: Strategic Customers & Programs at Schneider Electric. Based in Tennessee, he has three decades of experience with the organisation. We discuss the diverse range of products and services now offered by Schneider as well as the exciting opportunities for smart metering, microgrids, onsite battery storage and more.

In 2007 when Kim Feldborg arrived in New Zealand he was surprised at how cold and inefficient the houses were, despite growing up in much colder European climates. Originally from Denmark, Kim has built houses in Greenland, Norway, Germany and England. He now enjoys life in a Certifed Passive House he built himself in Taupō.

Richard Houghton now lives in a very good, healthy home. But that wasn't always the case. Along with Simon Cator from Pro Clima NZ, we discuss Richard's journey in designing and building an energy-efficient SIP home just outside Auckland, New Zealand. 

Zola Rose has a vision for regenerative housing as a solution for improving communities and sustainability. She brings diverse and international experience to Aotearoa New Zealand where she now calls Nelson her home.

Real estate has long been used as an investment and a means of making a profit in New Zealand. Zola explains how this has tended to undermine the values that we should otherwise associate with where we live. Housing should protect, shelter and foster community, but we've tended towards the commoditisation of housing.

There are solutions that can help provide better housing and helping people implement these solutions is the basis for Zola's social enterprise.

https://www.commonground.net.nz

Darren O'Dea is a self-confessed building physics nerd. Along with co-founder David Carroll, he has helped to create Speckel, a platform for designing low carbon, healthier, durable and energy-efficient buildings. Having proven popular with architects and consultants in Australia, Speckel is now available in New Zealand. Find out more at https://www.speckel.io/

Sabine Schoenberg is co-founder of the Smart Healthy Green Living network, a collection of videos and streaming content on everything from tiny homes and carpentry to interior design and gardening. Through her network, Sabine is promoting the 'Do One Thing' campaign to help everyone take a step towards living a more sustainable life.

My third conversation with Simon Cator in our series on the control layers of a well-performing building envelope. In this episode, we cover the why and how of airtightness.

Following my previous chat with Simon Cator we continue our discussion about how to construct a good building envelope. This week we're focussing on keeping the weather out. We cover the benefits of a monolithic membrane instead of a microporous one, the importance of being resistant to water while maintaining permeability to vapour, and how to keep everything connected.

Casey Curtis shares tips on how and why to create airtight buildings, the benefits of mid-build open homes, and using collaborative design to create the right house on any given site.

Michael Rubino is an educator, author and an expert in mould remediation of homes. In this interview he shares his journey and some tips on how we can make our homes a better, healthier place to live.

Simon Cator is passionate about helping people to build better homes. Prior to becoming Regional Sales Manager for the Upper North Island at Pro Clima NZ, he worked for New Zealand's online architectural products library - EBOSS and also HRV before that.

In this introductory episode, I spoke with Simon about the diversity of his role at Pro Clima and how he talks with people throughout the whole building industry to help change the way we do things.