This is an amazing book - I cannot recommend it enough. If you get the chance to browse it anywhere, do - chances are you'll buy it. I bought it in the early seventies and have been browsing it ever since. It is full of wonderful images from all over the World, of houses, dovecotes, castles, grain stores and the like built by people without formal training (but often with a lot of crafts knowledge, obviously). It is endlessly fascinating - to dream away with, to inspire, to get itchy feet with, to organize an immediate trip from. There are other books on the subject (Oliver springs to mind) but this was the first, and in many respects it remains the best. Rudofsky has a fine style in writing, too: an open mind and a vast knowledge, coupled to a good sense of humour. Buy this book, you won't regret it.
I borrowed this book from Manchester's Central Library in about 1978 and loved it so much I wanted to steal it from them! I did give it back but it preyed on my mind for decades - because it was so beautiful and captured something of the universal spirit of humanity. The pictures all have something in common. It used to be a rare book because it was the exhibition catalog for a show at the NY Gallery Of Modern Art. Eventually I found a copy in the 1990's. The text is thoughtful and insightful too. There is a section on walled towns (and this is from memory of reading this in 1978 - to give you some idea of how it affected me!) where the author points out that most often walls were built to limit and delineate the size of a planned community - not mainly to defend against attack. He points out that most city walls would fail defensively. The pictures are fuzzy, old and BnW - maybe this increases the sentiment - but I think the time is right for someone to repeat the project in modern times. Especially now we have maniacs destroying the world architectural heritage - bye bye Palmyria, Bye Bye!
If you are looking at a quick read about some not-quiet-mainstream architecture, then this book is great for that. It is short, and black and white, but the projects that it encompasses give an interesting perspective on architectural knowledge, and building practices.