A recent visit to mid-Wales allowed a first hand experience of composting toilets, living in a yurt and additional research into low-impact solutions at CAT. CAT is the Centre for Alternative Technology near Machynlleth. It has developed over the years from a place for pioneering spirits to call home, to a world recognised centre for research and education. At the visitor centre there are many displays showing different technologies, both low and high tech, from the simple greenhouse to solar panels and electric conversion. Our yurt was a relaxing space to stay, although another reminder for the importance of proper ventilation in control of moisture. The traditional mongolian yurt has an open high-level oculus at the centre venting the tent from above. Here in Wales however, a clear pvc cover has been fitted over this to prevent the rain coming in. Without this high level ventilation and a constant fire drawing air through the yurt there was very little movement of air and it became a bit stuffy in the hot summer days, releasing the night’s moisture vapour out of the felt walls. Composting toilets are a waterless system relying on natural decomposing rather than flushing away. Sawdust is sprinkled in to help with drying out and therefore controls odours. In rural areas getting toilets onto mains drainage can be costly and severely limiting for a project. Anybody on a cesspit system would benefit from using less water as this fills up the tank. Using and researching the composting toilets was useful to be able to advise potential clients who wish or need to be off mains drainage. They were clean, simple and pretty odour free. Keeping up-to-date with renewables technology is important as this area is always developing however, often the simple time-tested systems are the best such as controlling solar gains and heat losses through proper site orientation and roof overhangs, planting and shading etc. Using less first, and adding technology to reduce the impact of what is used, second, is a good mantra to follow. If you are in the area or nearby I can recommend a visit it CAT, even if it is just to ride their gravity-fed, water-powered and electric and fuel-free cable car! Pictures: Top: Central roof vent within a yurt, Mid: Thermal non-structural rammed earth wall capturing solar heat and regulating humidity; Bottom L: Simple sliding external solar shading: Bottom R: Solar glazing shades and produces electricity.