The YAYA winner’s shimmering King’s Cross office more than justifies the developer’s decision to put its faith in emerging talent, writes Elizabeth Hopkirk Argent’s 30-hectare King’s Cross development in central London is a compendium of fashionable architects, a reference book in built form. They have got a Chipperfield, a Heatherwick and a Maki, plus a Brooks in gestation. Into that starry anthology, the fruit of Allies and Morrison’s now 20-year-old masterplan, a few younger practices have been invited to pitch. One of the last schemes to be completed is Coffey Architects’ shimmering 22 Handyside Street, an £18m three-storey office building that stands at the very eastern edge of the estate where it rubs up against York Way, that still-grimy artery leading north through railway badlands from King’s Cross station towards Islington.