Cross Laminated Timber Explained: Carbon, Cost & Construction

Dean sits down with Sean Bull from Xlam to unpack cross laminated timber (CLT) — how it’s made, how it performs, and whether it can play a meaningful role in reducing embodied carbon across Australian construction.Sean shares his journey from structural engineering and post-tension concrete into the mass timber space, and explains how CLT panels are manufactured, pressed and machined in Australia using radiata pine sourced from PEFC-certified forests.The conversation explores:What CLT actually is and how it’s manufacturedFire resistance levels (FRLs) and performance pathwaysAcoustic considerations in multi-residential buildsEmbodied carbon vs biogenic carbon storageEnvironmental Product Declarations (EPDs)Forestry certification and sustainable sourcingThe impact of the Black Summer bushfires on timber supplyInstallation timeframes and on-site efficienciesCost comparisons with concrete structuresReuse and circular economy potentialWhether mass timber can realistically scale to meet housing demandSean also discusses a recent Luigi Rosselli project in Sydney and what’s required to bring CLT into mainstream housing, from design decisions to stakeholder.Links & Resources:Xlam Australia: xlam.com.auEnvironmental Product Declarations (EPDs) – Xlam: xlam.co/resourcesPEFC (Programme for the Endorsement of Forest Certification): pefc.orgResponsible Wood (Australian PEFC member): responsiblewood.org.auLiving Building Challenge: living-future.org/lbcLuigi Rosselli Architects: luigirosselli.comMass Timber podcast: masstimberpodcast.comHosted by Dean Ipaviz, builder & director at Verdecon, creating high-performance, low-impact homes across Australia. Follow Dean Ipaviz and @_thebuiltenvironment on Instagram and visit thebuiltenvironment.com.au