If you thought that straw bales were only for DIY backyard builders, think again.

In today’s episode we move onto our next sustainable design theme - renewable materials.

We’ll investigate the design of a new certified Passive House built from Huff’n’Puff SITUP strawbale wall panels. This house is located on an off grid site in the cool temperate Victorian high country.

Architect Talina Edwards, a director at Envirotecture, shares the inside story on her Huff’n’Puff Haus.

Today we’ll learn about:

Biophilic design and our intrinsic connection with nature, Country and our planet
The costs and benefits of using straw bale panels and their role in construction
Strategies to achieve Net Zero carbon, and
A wealth of insights and practical information drawn from Talina’s extensive experience

Australian Architects can earn formal CPD hours by listening to these podcasts and completing an online quiz.

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. Biophilic design is linked to care for Country and an understanding that we are part of nature and intrinsically linked with our planet. If we don't care for Mother Earth, she can't keep caring for us. It's a reciprocal relationship of being present, responsible and caring. Like we take responsibility to care for our family.

We feel better when we're outside in nature, but most of us spend around 80% of our time indoors. Biophilic design is about creating indoor environments that help us feel closer to nature and the outdoors through ideas such as plants, natural light, textures and materials. But it's critical to be very mindful of how our design choices affect the environment. Because remember, it's not only about what is good for us, it's a reciprocal relationship.

2. The primary driver for using straw bale panels is to create maximum wall insulation in colder or more extreme climate zones. Other benefits include being a renewable material, low embodied carbon and reuse of a waste product from the agricultural industry.

3. Huff n Puff straw bale wall panels are made from straw bales tightly fitted inside plywood box frames. The panels are typically 350 - 450mm thick, approximately 600 - 1200mm wide and 2.5 – 3m high depending on the project requirements and they're engineered to be load bearing.

4. Lime mortar or clay mortar can be used on the exterior or interior to seal the straw bales. Limemortar is a natural breathable material that is airtight but vapour permeable, meaning the building can sweat through it. If rendered externally, large eaves are critical to protect the external render from weathering.

5. Materials like straw bale and hempcrete are not in the building code, so additional consultant reports and engineering input is required. On this project, there were three structural engineers in total: the project structural engineer, the engineer from Huff n Puff for their SITUP panel system, and a third engineer to independently review and verify for the building surveyor.

And finally,

6. The use of straw bale panels worked out time and cost comparable to custom builds based on the use of 140mm timber stud framing that Talina typically uses for colder climates. Note: 140mm framing allows for the additional thickness of insulation and is more expensive than 90mm stud framing and insulation used in the majority of Australia.

INTERVIEW QUESTIONS

[00:00:00] Introduction

[00:01:17] How did you get started in sustainable design?

[00:05:03] What is Biophilic design?

[00:07:47] We are Nature – what does this mean?

[00:10:57] Is interest and awareness and knowledge in sustainable design increasing?

[00:12:03] What was the design brief?

[00:13:29] What were the climate design objectives?

[00:17:07] Why did you decide to build a certified Passive House?

[00:18:52] How much mechanical heating and cooling is used?

[00:19:34] Can you have an open fire or wood burner in a Passive House?

[00:22:29] Had you built with strawbale before?

[00:25:02] How did traditional strawbale evolve into strawbale panels?

[00:30:28] Explain what strawbales panels are and the design and construction process

[00:38:18] What are the challenges of using strawbale panels?

[00:43:24] Does using strawbale panels save time and cost?

[00:45:59] Are Strawbale panels suited to all climate zones?

[00:48:42] What did you use for the exterior cladding?

[00:50:13] What are the pros and cons of using lime or clay mortar?

[00:53:41] What are the key considerations to achieve Net Zero carbon?

[00:56:40] Where did you get your data to determine your carbon calculations?

[01:00:27] What are the windows made off and where did they come from?

IN THE NEXT EPISODE

Next week we continue our exploration of renewable materials.

We'll investigate the use of hempcrete in the renovation of a Federation home on an inner suburban site located in Ashbury in warm temperate Sydney. I talk to Emily Knight, Director of Emily Knight Design, who will give us the inside story on her AL project.

RESOURCE LINKS

ENVIROTECTURE WEBSITE

Project Page (Completed images) www.envirotecture.com.au/projects/project/huff-n-puff-haus

Blog Post (Construction images) www.envirotecture.com.au/resources/resource/strawbale-sit-up-panels-under-construction

Little Pot of Gold research project https://www.envirotecture.com.au/projects/project/little-pot-of-gold

PROJECT INFO

Strawbale panels - Huff’n’Puff Constructions https://glassford.com.au/main/

Exterior Cladding - Cemintel Barestone Cladding www.cemintel.com.au/product/barestone/

Certified Passive House Doors & Windows - Logic House www.logikhaus.com.au

CARBON CALCULATIONS

Alex Slater, Building Physics Australia - Passive House Consultant & carbon calculations

https://buildingphysics.au/

Environmental Performance in Construction database, University of Melbourne

The EPiC Database is a comprehensive and consistent open-access Life Cycle Inventory of environmental flow coefficients for construction materials, containing over 1,000 embodied emissions, energy and water coefficients

NABERS Embodied Carbon Tool - www.nabers.gov.au/ratings/our-ratings/nabers-embodied-carbon

OTHER INFORMATION

The Living Building Challenge https://living-future.org.au/living-building-challenge/

Sustainable House Day https://sustainablehouseday.com/

Off Grid Festival - https://www.offgridevent.com.au/