Brought to you by the Architects’ Journal. AJ sustainability editor Hattie Hartman and co-host Joe Jack Williams talk to changemakers and innovators who are transforming architecture by designing in ways that respect planetary boundaries. Nominated for Audio Content of the Year at the PPA Awards 2025.
Show notes & more info here: https://www.architectsjournal.co.uk/podcasts
Ana Belizário: ‘Timber should be the material of choice in the global south’
Episode 61. AJ Climate Champions with Hattie Hartman and Joe Jack Williams.
In this episode, we turn our attention to the global south. Ana Belizário describes Brazil’s burgeoning mass timber movement, which includes notable exemplars such as the Children's Village School (in Tocantins in northern Brazil) which won the RIBA International Prize in 2018. Many talented Brazilian architects are shifting their focus from concrete to timber.
Belizário cites Waugh Thistleton’s Murray Grove as a precedent many Brazilians designers initially strove to emulate. By now there are many more typologies and approaches, including a high-end retail complex in São Paulo’s fashionable Pinheiros district which will open in early 2026.
We also discuss the biodiversity challenges of pine and eucalyptus plantations, which supply Brazil’s mass timber industry, including their potential for growth and how they relate to native species.
Belizário argues that hybrid construction is a crucial way forward. While not carbon negative, hybrid construction is an easy win because the industry ‘feels safe’ with it, according to Belizário. ‘Every cubic metre counts. A thousand hybrid structures is better than one super mass timber structure that will never come,’ she explains.
At the time of recording, Belizário had just returned from COP 30 in Belém where Built by Nature launched its Principles for Responsible Timber Construction. She describes the five principles as a useful tool for a project, a company, or even a country to situate itself on its timber journey and develop an action plan for the various points.
Post-COP, Belizário is hopeful. ‘Sustainability got popular,’ she says.
Reflecting on how Brazil’s mass timber industry has grown in recent years, Belizário hopes that within five years Urbem will be able to boast an all-female mass timber installation team!
For show notes and to catch up on all AJ Climate Champions episodes, click here.
Supported by Built by Nature
26 Nov 2025
Kirsten Haggart: Building with timber has reached a ‘tipping point’
Episode 60. AJ Climate Champions with Hattie Hartman and Joe Jack Williams.
In this episode, we take a deep dive into building with timber. Haggart shares numerous tips for practices just getting started. Early engagement with the supply chain and getting the right engineer are essential. Efficient use of timber is essential, as is designing for longevity and adaptability by getting column grids right and incorporating ‘soft spots’ where connections between floors can be introduced at a later date. Managing moisture by designing out wet trades is just as critical as fire risk.
Haggart also explains how engineered timber structures can be designed for circularity. She sees a future of more manufacturer take-back schemes, rather than the current fledgling approach of one-to-one reuse between a host building and a donor building.
Waugh Thistleton's Black & White Building recently won global recognition as a winner of the Built by Nature prize, recognised particularly for its efficient use of timber in both structure and facade and an informative LCA report which sets out the metrics behind the building in an engaging and accessible manner that others can learn from.
Current projects in the pipeline include a twin office building for Lendlease on the Milan Expo site, a stone clad office tower in Maidenhead and collaboration with community housing practice We Can Make in Bristol.
For show notes and to catch up on all AJ Climate Champions episodes, click here.
Supported by Built by Nature
12 Nov 2025
Joe Giddings on the ‘mind-blowing’ growth of bio-based materials in Europe
Episode 59. AJ Climate Champions with Hattie Hartman and Joe Jack Williams.
On the eve of Cop30 in Brazil, Built by Nature European Networks Lead and ACAN co-founder Joe Giddings talks to the AJ about how to build responsibly with timber.
Giddings takes a deep dive into Built by Nature's (BbN) five Principles for Responsible Timber Construction, which provide a holistic framework for building with timber without unintended consequences. He also describes BbN’s workstreams to quantify and promote lean use of timber. Current research includes the development of two new metrics for assessing the impact of building with timber: the use renewal ratio (the length of timber remains locked up in a building compared to how long it takes the tree that supplied it to grow) and wood use intensity, the volume of timber used per square metre of building.
Giddings challenges numerous tropes. Local is not always best; what’s needed is a holistic understanding of what timber is abundant in the supply chain that is appropriate for a particular application. Monocultures of Sitka Spruce are not all bad; in the UK, they are a stronghold for red squirrels. Different aspects of biodiversity can drive different specification choices. Again, a holistic view is what matters.
He also describes his work with partners across Europe, including Bauhaus Earth in Berlin, BBCA in France and MassMadera in Spain. ‘I’ve been blown away by the pace and scale of change across Europe,’ says Giddings. He predicts that in the next decade, the pockets of innovation that have emerged in Denmark, Sweden and France will spread across Europe driven by EU legislation – and ‘hopefully the UK, too’.
For show notes and to catch up on all AJ Climate Champions episodes, click here.
Supported by Built by Nature
Who has been a guest on AJ Climate Champions
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Summer Islam
Melissa Mean
Tara Gbolade
Brisco Loran
Sarah Castle
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