Cellars in The UK
Cellars in the UK, however, were mainly included only in larger houses, and in houses built up to the period of World War I, after which detached and semi-detached properties were constructed without cellars, usually to avoid the higher building costs entailed. Since house building had increased vastly between the wars, the lack of cellars in more recent housing was to become a major problem in the Air Raid Precautions (ARP) programmes in the UK during World War II.
Alternatives had to be found speedily once it became clear that Germany was contemplating air raids as a means of demoralising the population and disrupting supply lines in Britain. Initial recommendations were that householders should shelter under the stairs. Later, authorities supplied materials to households to construct communal street shelters and Morrison and Anderson shelters.
Read more about this topic: Air-raid Shelter