PHINZ Webinar: Airtightness – Advice for an Airtightness Champion
Event details
In this webinar Jonathan Iliffe will focus on the importance of the architect in designing an airtight building, and why a clear understanding of materials and construction methods is so important from the outset. Good passive house outcomes depend on early design decisions, careful detailing, and collaboration across the project team.
Then Ross Brown will cover the practical aspects of achieving airtightness in a new build. He will talk about various construction details—things like sealing junctions, managing penetrations for services, and using tapes and membranes so the envelope meets passive‑house‑level performance.
Ross will also explain the value of the preliminary airtightness test, using a blower‑door to check the envelope before it is fully finished. This early test will identify any weak points and allow the team to ensure leaks while it is still easy to access services, joints, and linings.
Denise will follow this with a discussion on the practicalities and science behind airtightness testing.
Presenters:
Jon Iliffe, eHaus
Jonathan Iliffe is the co-founder and director of eHaus, one of New Zealand’s leading high-performance home builders. Since establishing the company in 2010 with Baden and Glenda Brown, he has helped pioneer homes built to the Passive House standard, focusing on comfort, health, and energy efficiency. With a background in mechanical engineering and a passion for better building performance, Jon has been central to eHaus’s mission to raise the standard of home design and construction in New Zealand.
Ross Brown, eHaus
Ross Brown is the owner of eHaus Waikato and Managing Director of Brown Construction Limited, a family‑owned, high‑performance building company based in the Waikato region of New Zealand. With more than two decades of construction experience, Ross shifted his focus to passive house and high‑performance homes after partnering with eHaus in 2014, securing the eHaus licence for the Waikato and helping to pioneer better‑performing homes in the region.
Passionate about building science and environmental responsibility, Ross is a Certified Passive House Tradesperson and a Licensed Building Practitioner who champions healthier, energy‑efficient homes that outperform standard building‑code housing.
Through eHaus Waikato and Brown Construction, he leads the delivery of passive house and high‑performance homes that combine comfort, sustainability, and quality craftsmanship, positioning himself as a leading advocate for better building standards across New Zealand
Denise Martin, BEO
Denise Martin is a PHI-certified Passive House designer and certifier, ATTMA accredited airtightness tester, and founder of BEO Building science — a building science consultancy working across New Zealand and Australia.
With over 15 years in high-performance building, Denise has worked with architects, designers and builders on residential and commercial projects on both sides of the Tasman — helping teams understand what it actually takes to deliver buildings that perform as promised, not just on paper.
As an ATTMA accredited training provider, she runs ATTMA L1 (residential), ATTMA L2 (Commercial) and general blower door workshops and hosts a monthly technical forum open to her ATTMA students and anyone in the industry looking for support. Got a tricky airtightness question? Just get in touch — the community is genuinely welcoming.
When: Tuesday, 28 April 2026, 12:30pm – 2pm
Cost: Free for PHINZ members
NZIA/ADNZ members receive a 25% discount
Non-members $30.00 plus GST
Where: online (Zoom)
CPD available
2 CEPH hours
15 NZRAB pts
With thanks to our fantastic Sponsors for this webinar!
5Merchants is a provider of high-performing and PassivHaus products & services to the New Zealand market. We are the NZ distributor for SIGA (est 1966). The SIGA product range works as a family of membranes, tapes and sealants to achieve a total air and windproof building envelope for residential & commercial buildings.
