The brand new 'historic' mansions dividing opinion

"What's implied in the word 'McMansion' is that it's been super-sized," Saumarez Smith says. "Everything is overblown, over-scaled, but it has no relationship with its context, like massive houses on small plots. Huge, pretentious porticoes, which have no real function other than to just look important." Done badly, he adds, the results can be almost comic, "like terrible plastic surgery".