Last reviewed: July 2026 · How we research these costs · Standards: Standards New Zealand My name’s Dave Petersen, and I’ve spent close to 19 years building and repairing retaining walls around Titirangi, Laingholm and the rest of the Waitākere foothills. The timber-or-concrete question comes up on almost every quote I write. Titirangi sections are… Read More: Timber vs Concrete Retaining Walls: Which Lasts Longer in Auckland? »