A stack of blocks teeters on the side of a busy road in Charlton, London, like a pile of shipping containers freshly offloaded from the nearby Thames. It is an arresting sight in this area of builders’ merchants and big box retail stores, each block thrusting out above the one below as if the whole pile might topple any minute. …“We wanted to create an eye-catching beacon,” says Michael Finlay, standing outside the new £5m Workstack.  …“Huge swathes of workspace have been lost,” says Finlay. “We feel like we’re the ones with our finger in the dyke.”  …Workstack is constructed from big sheets of cross-laminated timber (CLT), a material De Rijke has been championing since 2006, when dRMM designed a music and sports hall for Kingsdale school a few miles away.