The Stirling Prize is the Baftas for architects, a moment for auto-erotic self-congratulation. Awarded by the Royal Institute of British Architects, its premise is straightforward: it’s for Britain’s best building of the year. But this year, it seems the prize committee has struggled even with this. Among the six projects shortlisted for this ostensibly nationwide prize, four are in London and a couple could barely even be considered buildings at all.