What difference does three metres make? Plenty, according to a story from the Edinburgh Evening News: a mistake in the location of old flats on an Ordnance Survey map is being blamed for a new housing development being built in the wrong location. Three metres is enough, apparently, to overshadow nearby residences. As Roger notes (with hilarious effect), there’s a lot of buck-passing going on about this at the local level, but the Ordnance Survey contends that its maps are no replacement for a proper engineering survey.