House prefabrication using flat pack panels delivers multiple environmental and cost benefits and is the way of the future.

In today's episode, we dive into our next sustainable design theme, prefabrication, and we'll explore house design and construction using cross laminated timber. Architect Jae Warrander, director of Makers, shares the story behind his Akaroa Bach: a prefabricated holiday home situated in a mild temperate climate on the east coast of New Zealand's South Island.

Makers, located in Wellington, New Zealand, is a collaboration between Makers of Architecture and Makers Fabrication.

Today we'll explore what CLT is, the process, benefits and costs of using CLT for prefabricated panel construction, and the ideal scenarios for utilising CLT.

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. Cross Laminated Timber (CLT) is an engineered wood panel product created by gluing layers of timber together with the grain alternating at 90 degrees for added strength. CLT panels are cut into entire wall, floor and roof sections with precise computer accuracy.

2. CLT buildings must be meticulously designed and this includes all openings and holes cut for doors and windows, services, fittings and even power points. Everything must be accurately located in the computer shop drawings because making changes on site is very challenging.

3. The CLT serves as both the internal wall lining and the structural shell. Externally, it needs thermal insulation, a weather and air tightness building wrap and cladding for weatherproofing. Internally, makers utilise prefabricated stud frame walls in conjunction with CLT to accommodate access to services, particularly in bathrooms.

4. Once prefabricated, the CLT panels are transported to the site and assembled to create the entire building form. The construction timeline is streamlined because site foundations, retaining walls and service connections can occur simultaneously with the off site CLT prefabrication.

5. Prefabrication using CLT offers several advantages:

• It replaces studs, bracing and other structural components.
• It eliminates the need for trims such as skirtings, cornices and architraves.
• It's made from locally sourced New Zealand pine.
• It reduces construction time on site.
• It enables building on remote or difficult to access sites, sometimes even by helicopter lift, and
• Off site construction minimises waste and enhances building quality.

6. Makers Fabrication are professional builders who also offer CLT cutting and prefabrication services to other architects and industry.

And finally, don't take my word for it. You can find out what it's like to live in a CLT house for yourself. The Akaroa Bach is available for holiday rentals on Airbnb. Find the link in the show notes

INTERVIEW QUESTIONS

[00:00] Introduction

[01:14] How did Makers start?

[04:30] In your experience is interest in sustainable design changing?

[05:23] What was the design brief?

[07:12] What is CLT?

[11:10] Does CLT replace the stud frame?

[12:08] What is the external wall build up?

[17:29] How are services integrated into the external frame?

[19:29] How are doors and windows incorporated?

[22:05] Where does your timber come from?

[22:27] Do CLT structures go on posts or a concrete floor slab?

[26:19] How do the interiors work?

[33:02] How does the structure work – are there posts and tie down?

[34:20] How do you work out if a site is suitable for prefabrication?

[35:39] Is CLT and prefabrication suitable for extensions?

[36:31] What is the benefit of CLT over standard prefabricated timber stud frame?

[41:50] Are panelised systems (CLT or stud frame) more cost effective than standard construction?

[43:09] Are the services of Makers Fabrication available to other architects and industry?

[45:32] How would an architect work with you if they wanted to utilise Makers Prefabrication?

[47:18] What advice would you give to anyone wanting to build with CLT or stud frame prefabrication?

[49:34] Key points summary

IN THE NEXT EPISODE

Next week we continue investigating prefabricated panel systems.

We'll explore structural insulated panels, or SIPs and their use in a new Passive House located on a very challenging site in the mild temperate climate of Wellington, New Zealand. Architect Murray Robertson, a director of Robertson Architects in New Zealand, will share the story behind his Bell House project.

And finally today, if you're enjoying my podcasts, I would love it if you would leave me a review or a star rating. To help others find the show, head over to www.ratethispodcast.com/renovationcollaborative  and follow the simple instructions.

RESOURCE LINKS

MAKERS OF ARCHITECTURE - Project Page (images) https://www.makersofarchitecture.co.nz/project/akaroa-bach

MAKERS FABRICATION – CLT Construction (general images) https://makersfabrication.co.nz/

MAKERS WEBSITE https://makers.co.nz/

PROJECT INFO

Terra Lana wool insulation: https://www.terralana.co.nz/

PIR Insulation NZ: https://greenstuf.co.nz/product/greenstuf-pir-panel/

ProClima Building Wrap

Bathroom light wall - Multi-wall Polycarbonate cladding

Timber floor finish: Osmo Polyxoil Raw (white tinted finish to keep pine looking natural and prevent it yellowing)

Australia: https://www.osmoaustralia.com.au/products/polyxoil-raw-

NZ: https://www.osmo.co.nz/product/Polyx%C2%AE-Oils%20Raw%20and%20Natural%20

OTHER INFO

XLAM https://xlam.co/

Airbnb – Bellbird Bach – Akaroa

https://www.airbnb.com.au/rooms/1354774335327608889?search_mode=regular_search&adults=1&check_in=2025-06-01&check_out=2025-06-06&children=0&infants=0&pets=0&source_impression_id=p3_1748433124_P3K8SODsiituoEQ5&previous_page_section_name=1000&federated_search_id=96e3ba2d-19ed-4949-b1ad-071d0ff392e4

Makers of Architecture - Warrander Studio https://www.makersofarchitecture.co.nz/project/warrander-studio

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].