In his 1912 pamphlet for the Garden Cities and Town Planning Association Nothing Gained by Overcrowding, Raymond Unwin set out in detail the lessons learnt from his formidable practical experience in the design and layout of housing: at New Earswick from 1902, Letchworth Garden City from 1905, and most significantly at Hampstead Garden Suburb, where the 'artisans' quarter' 1907-9 was probably his masterwork of spatial design. His interest in minimising the length of paved road to number of houses served, and 'greening' the ubiquitous mechanistic bye-law suburb of the late 19thcentury provided motivation for defining a general theory of design, which under pinned Garden City principles. Nothing Gained by Overcrowdingemerged as a principle which was to have a revolutionary impact on housing and urban form over the next 50 years. Unwin's theory had developed with his work, but the origins can be found in two earlier and less well known publications. On the building of houses in the Garden City' was written for the first international conference of the Garden City Association, held in September 1901. The following year he published the Fabian Society Tract Cottage Plans and Common Sense, in which he took first principles, 'shelter, comfort, privacy', and drew out general criteria and specific standards. Housing had to be freed from the bye-law strait jacket. This would sweep away 'back yards, back alleys and abominations … too long screened by that wretched prefix back'. Republished here for the first time together, with an introductory essay by Dr Mervyn Miller, these three papers make clear the development of Raymond Unwin's theories of planning and housing, theories which were among the most influential of the 20th Century.