Britain’s planning laws are often described as slightly mad, unfit for purpose and antiquated. But this nugget, reported by Phineas Harper in The Guardian and highlighted by John Naughton, is quite delightful:

British domestic architecture has also been shaped by idiosyncratic rules that contribute to its poor environmental credentials. For instance, in many parts of the UK, homes that face each other at the rear are required to be built 21 metres apart. This large distance means that instead of clustering buildings together around cool courtyards or shady streets, as is common in hotter climates, many homes in new neighbourhoods are directly exposed to the sun.

The 21-metre rule is, according to the Stirling prize-winning architect Annalie Riches, a bizarre hangover from 1902, originally intended to protect the modesty of Edwardian women. The urban designers Raymond Unwin and Barry Parker walked apart in a field until they could no longer see each other’s nipples through their shirts. The two men measured the distance between them to be 70ft (21 metres), and this became the distance that is still used today, 120 years later, to dictate how far apart many British homes should be built.