As the historic town of Leuven strives to become carbon neutral, it is transforming how its building are made – and demolished. Are there lessons for the rest of the world?

Kelly Sempels’ dad was a builder, most of her five brothers are builders, and, until leaving her last job, she too was a builder. Now, after a career fixing roofs and laying bricks Sempels is plying a new trade: “urban mining”. She and her crew of six still dress and talk like builders, but their focus now revolves less around construction than dismantling.

“I love it when I can go to work and learn something new,” says the 43-year-old, pointing to a pile of laminate floor tiles in the corner of the terrace house that she is helping to strip. “Like how to break wooden floors without actually breaking them.”