About This Episode
Derek Bilby, CEO of Contech Companies, brings a specialist construction perspective with 30 years of experience across civil, IT (Fletchers), and now specialist concrete work. Contech operates across Auckland, Wellington, and Christchurch with ~100 staff, specialising in repair, refurbishment, and asset life extension, a company with 60+ years of history and staff with 25+ years tenure. The central argument: repairing and extending the life of existing buildings is often better than demolishing and rebuilding, for sustainability, for cost, and for investment returns. Global investors increasingly favour sustainable, low-carbon refurbished assets with higher returns. The concrete paradox is acknowledged, concrete contributes 8% of worldwide carbon emissions, yet there's no viable replacement. Solutions include supplementary cementitious materials (SCMs), fly ash, and slag to reduce cement content, targeted concrete mixes for different building elements (foundations vs columns vs slabs), and increased post-tensioning which significantly reduces reinforcing quantities. Refurbishment risks come from unknowns, the key is thorough investigation upfront. Average workforce age in his company is mid-40s, explaining why technology adoption is slow. Digital devices on site only arrived around 2010-2011 (iPad launched 2009). He's optimistic that AI will accelerate tech adoption "extremely quickly."
Key Topics Discussed
- Repair vs rebuild. Sustainability, investment, and practical arguments for asset life extension.
- Concrete paradox. 8% of global carbon emissions, no viable replacement yet.
- SCMs and targeted mixes. Reducing cement content, right mix for right purpose.
- Post-tensioning. Efficient low-carbon construction method.
- Asset owner drives decisions. Green star ratings, sustainability marketing.
- Workforce age. Average mid-40s, explains slow tech adoption.
- Digital adoption timeline. iPad 2009, digital tools on site from 2010-2011.
- AI acceleration. Will speed tech adoption "extremely quickly."
Notable Quotes
Concrete contributes 8% of all worldwide carbon emissions.
Average workforce age mid-40s, "No wonder technology adoption is not great."
iPad only came out in 2009, digital tools on site are barely a decade old.
Guest Background
Derek Bilby is CEO of Contech Companies, specialist construction (repair, refurbishment, asset life extension). 30 years experience across civil, IT/Fletchers, and specialist concrete. ~100 staff across Auckland, Wellington, Christchurch.
