If I remember correctly, the Alliance Française building in Mitchell's Plain, Cape Town was built of compressed earth blocks made using a simple hand-operated press. The blocks had some Portland-cement content because the material available on site was mainly sea sand, which lacks the grain gradation to gain substantial cohesion under pressure.

The problems with compressed earth in the sorts of urban contexts in which the key to much sustainable settlement lies are structural limitations and site-inefficiency, compared to conventional clay brick and mortar. In other words, while four-storey structures might be perfectly feasable in these materials, the concomitant wall thicknesses at street level represent an unwelcome additional constraint on planning on already tight sites. And a four-storey vernacular on tight urban sites is precisely what sustainable settlement needs.

Not that the primary problem of shelter in Africa is one of bricks. There really is nothing wrong with fired clay brick - it is an extremely durable natural material - except that the brickfields belong to the wrong people. It is better if clamp-fired using coppiced riverine poplar or willow.

I will be happy to assist technically in building CEB presses locally. I am currently based in Cape town and have 20 years machine shop experience.

oops AFK there abit. I'm in Muizenberg. mail mosesashton@gmail.com