Found a very good series of videos on how to build a cob pizza oven by the build naturally channel – loads of interesting videos on there, including information on how to test clay content in soil and how to sift clay – along with how to build cob – which is relevant to other heat related topics such as rocket stove mass heaters.

Looking into making my own methane from kitchen waste – have known about this for a long time but this new design I saw is quite nifty – will update this page once I have the materials to attempt it