Regenerative Design & Circularity – Andrew Noonan, Andrew Noonan Architect

Renovation Collaborative

Reducing carbon emissions, both embodied and operational, is now a design priority. But carbon cannot be considered in isolation.

Today we continue with the latest science and investigate the importance of holistic decision making and regenerative design. We'll explore the renovation and extension of a 150-year-old timber cottage on a small inner city suburban site in Turrbal Country, subtropical Brisbane.

Architect Andrew Noonan, director of Andrew Noonan Architect, shares the inside story on renovating his own home. Andrew conducted extensive research on his design, material and product choices to ensure they achieved optimal regenerative outcomes and he shares his very interesting findings.

Today we'll learn about:

• the importance of regenerative design and circular economy thinking,
• specifying timber from environmental sources,
• the long term problems with using dark colours in hot climates,
• why plasterboard wall linings are actually a very environmental solution, and

loads of other insights and practical information from Andrew's extensive research and years of experience.

Australian Architects can claim 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. Reducing carbon emissions through design is critical, but we must think holistically and find regenerative design solutions that do not focus on carbon at the expense of everything else. Regenerative design aims to integrate the building into a broader system, emphasising ways to give back and create a positive impact rather than merely reducing negative impacts.

As an example, Andrew could have achieved 10 star NatHERS but chose not to because achieving it would have required upgrading from single to double glazing. This change would have significantly increased his embodied carbon due to the added glass. NatHERS modelling proved that his house design would be comfortable in a subtropical climate without mechanical heating and cooling, and so double glazed windows were not essential.

2. Relying on rooftop solar power to offset large household energy consumption is not a balanced regenerative approach. It's crucial to prioritise reduction over production. Always explore ways to reduce energy demand first.

3. Getting the fundamentals of climate responsive design right is a vital starting point for all designs and will significantly enhance energy efficiency.

4. Choosing light coloured exterior paint in hot climates can minimise heat gain and prolong the life of exterior materials. Timber is particularly vulnerable to damage when painted dark colours because the paint essentially seals it in plastic. Dark painted walls and windows absorb large amounts of heat when exposed to the sun, causing the timber inside to steam and break down over a reasonably short time frame. Be aware that most timber window manufacturers in Brisbane and presumably in other hot climates have disclaimers about dark paints on their products which can void warranties.

5. Always investigate the origin of your timber. If you're choosing new timber, ideally find timber grown locally in Australia or New Zealand. Only choose timber with valid third party forestry certification, FSC or PEFC, to uphold environmental protection and human rights.

In recent years, many states in Australia have significantly reduced hardwood logging from native forests, making local hardwood more difficult and expensive to obtain. Be aware that affordable hardwood species commonly used for clear finished doors and windows in Australia, like New Guinea rosewood, lack third party chain of custody certification.

And finally,

6. Andrew discovered that plasterboard is a very environmental product from a circularity perspective. Initially he believed plywood would be a better option for internal linings, but he found that it contained a highly carbon intensive glue. Additionally, there is no pathway for plywood products to have a second life. Their only circular outcome is energy recovery, meaning incineration. In contrast, plasterboard has a significantly lower whole of life impact than plywood. The gypsum used in plasterboard is easily recycled to create new plasterboard from old materials.

It's important to note that the material choices made on this project are not universally applicable to all projects. Each project has unique requirements and solutions should be explored on a case by case basis.

INTERVIEW QUESTIONS

[01:42] Can you tell us about your practice and how you got started in sustainable design?

[02:59] What is Regenerative Design?

[04:17] What is the Living Building Challenge?

[10:12] What was the project design brief??

[12:23] What were the key environmental initiatives for this project?

[15:51] Why is chome finishing bad?

[16:44] Why did you use a timber framed floor as opposed to a concrete slab?

[21:58] Can you explain Circularity on your project?

[25:56] How does you design respond to the subtropical Brisbane climate?

[29:30] Can you explain how to optimise breeze flow through a house?

[30:18] Can you tell us about your NatHERS rating and why you chose single glazed windows?

[32:33] Can an energy efficient house still use gas for cooking?

[34:19] What sustainable materials did you choose for the building exterior?

[37:32] What are the problems with using dark external colours in hot climates?

[40:13] How to choose environmental timber for doors and windows

[42:08] What is timber third party chain of custody certification (FSC and PEFC)?

[49:53] Why did you choose plasterboard for your building interior?

IN THE NEXT EPISODE

Next week we move on to the sustainable design fundamentals - carefully considered floor plans that utilise space efficiently and are responsive to the climate and surrounding site.

We'll investigate the design of a new house on a small suburban site located in Palm Cove in tropical North Queensland. I talk to environmental architects Belinda Allwood and Allison Stout from People Oriented Design who give us the inside story on their Big Small House project.

This season covers a wide array of environmental ideas. I welcome your feedback on topics you'd like to see explored in more depth over the future seasons.

RESOURCE LINKS

ANDREW NOONAN ARCHITECT WEBSITE

Website Project page - 39s House www.anarchi.com.au/projects/39shouse

OTHER INFORMATION

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

Third party Timber Chain of Custody Certification (FSC & PEFC) - Australia & New Zealand - https://www.agriculture.gov.au/agriculture-land/forestry/australias-forests/certification

Responsible Wood (PEFC) - https://www.responsiblewood.org.au/what-we-do/why-we-exist/

External cladding - https://weathertex.com.au/

Construction Waste recycling – PlanetArk – Business Recycling - https://businessrecycling.com.au/

GET IN TOUCH

If you've got any comments or questions or there's any topic you'd like to know more about, please send me an email at [email protected].