…Since CLT was invented in Austria 25 years ago and first received serious exposure with Waugh Thistleton’s first timber tower a decade ago, interest in and use of the material has exploded. CLT manufacturing plants are being built wherever there are trees. Timber towers are getting taller. It is marvellous stuff that is displacing a lot of concrete. I like it and I write about it a lot. …We say that wood is a renewable resource and it’s true; Sandra Frank noted that the wood in her company’s Strandparken project was replaced by new growth in 44 seconds. But as I learned recently from Grace Jeffers, trees might be renewable, but forests are not. …Given the pressures on our resources, do we not have an obligation to choose the system that uses the least amount of material, even if it is renewable?