Passive House Design: Subtropical – Tiago Guerreiro, H4 Living

How do you design a Passive House in a Subtropical climate like Brisbane?

Today’s episode is the fourth and final episode focussing on the design specifics for each of the four climate zones around Australia, where most of our population lives.

I talk to very experienced passive house designer Tiago Guerreiro, a director at the award-winning design and construction company H4 Living based in Brisbane. In this episode, Tiago explains the Passive House design specifics for Subtropical, plus he shares heaps of other information and insights about designing and building from his years of experience to help you better understand Passive House.

Australian Architects can claim formal CPD hours for these podcasts.

MORE INFORMATION

Find everything you need on the Renovation Collaborative website.

www.renovationcollaborative.com.au

• PODCAST Key points summary, timestamps and resource links
• FREE RESOURCES Transcript edited into clear Q&A.
• CPD Australian architects can find more information on CPD, and
• COURSES Eleven easy to read courses demystifying the entire home design and construction process.

KEY POINTS SUMMARY

1. The 5 Passive House design components for a subtropical climate are as follows:

• Windows are typically double-glazed and always operable. Windows should enable cross ventilation, purging of any excess heat build-up, and connection to the outdoors to enjoy comfortable external temperatures over spring and autumn and much of winter.
• The fresh air circulation system for subtropical is an ERV (energy recovery ventilation system) which is different to the HRV systems used in the cooler southern states.
• Wall insulation can fit within a typical 90mm timber stud framed wall thickness. No under-slab insulation is required because connecting to comfortable earth temperatures (usually around 22-23 degrees Centigrade) is beneficial for cooling.
• Only one layer of external wrapping is required; the vapour-permeable weatherproof membrane on the outside of the home is taped, sealed and made airtight. An additional internal membrane may be used to obtain certainty of airtightness, but it can be avoided in most cases to reduce costs.
• Removing thermal bridges is always essential to avoid heat gain.

2. Effective shading to avoid all heat gain is critical - no sun can enter the house. Passive houses retain heat very effectively because they are well-insulated and sealed; therefore, the hotter the climate zone, the more shading is required.

3. Humidity and condensation are major issues in subtropical design. It’s always essential to run a Wufi analysis (which is a moisture study) as well as the PHPP modelling to resolve any moisture issues and prevent unseen mould growth in the building structure over the long term. . If you’d like to hear more about the Wufi analysis you can find more information in Episode 4. Passive House Consultant and Certifier – with Luc...