to be passed on in ignorance of the broader tradition of the one night house and may feature picturesque details based on variants of the traditions noted above. These legends generally take the form of a prominent member of local society proposing a wager with a landless family that members who could raise a house in a night and a day could keep the property. Some versions of these legends may emphasise that the family may cheat and win out over the complacent authority figure by building a very small hut or by simply building a hearth and chimney. A good general account of one night house traditions is provided in the book Cotters and Squatters, by the British anarchist and writer on housing issues, Colin Ward. Ward considers the one night house tradition in the context of squatting and other informal systems of occupying and using land and relates accounts from England, Ireland, Scotland and Wales, which demonstrate clear parallels in different folk traditions. He observes that similar traditions exist in Turkey, France, and North and South America. Architectural development Very little is known in detail about the building of these structures, their numbers or inhabitants, and no accurate representations survive. Most Tai Unnos (pl.) were originally made of turf and soil, with a roughly thatched roof. Once established, the walls were often replaced with local materials, including clay and stone. An experimental construction in Carmarthenshire in 2006 demonstrated that a rudimentary structure could be assembled quickly. The squatters may not have depended exclusively on agriculture and in some areas may have worked in quarries and mines. This development led to dispersed settlement patterns seen in the Welsh landscape today. Materials from early stages of construction may have been replaced by higher quality timber and slates, available via the new railways. Single storey Tŷ Unnos cottages were modified by raising the roofs and enlarging the windows. The most recent known tŷ unnos was built in 1882. Four brothers built it in Flintshire. Oliver Onions fictionalized the story in his 1914 novel Mushroom Town. As a name for modular housing The "ty unnos" concept has been used as an inspiration for low-cost modular housing systems. The Welsh woodland charity called Coed Cymru used "Ty Unnos" as a name for a house design using local materials. In 2009, they were invited to show the design in Washington, D.C. as part of