Well, the question is not 'when did Britain let go of its territories'. The question is 'when did Britain lose the kind of involvement you need to get into low

Well, the question is not 'when did Britain let go of its territories'. The question is 'when did Britain lose the kind of involvement you need to get into low-level building regulation?' Near as I can find, they never had that kind of interest or involvement. Which is why I wanted a source for your claim that they banned traditional building materials. So my thinking is simple: prior to 1930 is a bit early for concrete blocks to be the logical building material outside of places like New York, and even there, it would be a bit newfangled. After 1930 is a bit late for the british to be really calling the shots about what gets built and how it gets built, since the period between 1945 and 1960 was characterized by increasing independence and english divestment. Maybe some university buildings? Anyway, this whole conversation is a bit of a strange digression from your original rather belicose response to my observation that concrete was not by any means the 'European way'. It's my feeling that, aside from some monumental architecture (which it seems nigeria also had) most europeans were also building with brick, wood, plaster and thatch, up until the 19th century. If you look at a modern timber frame house in the UK, the basic structure would be familiar to a roman architect. The timber structure is laid on brick piles, which are in turn laid on concrete foundations (the only modern addition - victorian houses often wouldn't have these), then a tile roof is fitted on top. It's a ridiculously ancient design.